ol.vips.operations

absolute value of an image

Operation name: abs.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

add two images

Operation name: add.

Returns an image handle.

Required inputs: - left → :left (image): Left-hand image argument - right → :right (image): Right-hand image argument

Optional inputs: - none

Outputs: - out → :out (image): Output image

append an alpha channel

Operation name: addalpha.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

affine transform of an image

Operation name: affine.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - matrix → :matrix (seqable of number): Transformation matrix

Optional inputs: - odx → :odx (float): Horizontal output displacement - ody → :ody (float): Vertical output displacement - idx → :idx (float): Horizontal input displacement - idy → :idy (float): Vertical input displacement - background → :background (seqable of number): Background value - premultiplied → :premultiplied (boolean): Images have premultiplied alpha - extend → :extend (keyword, see ol.vips.enums/extend): How to generate the extra pixels

Outputs: - out → :out (image): Output image

join an array of images

Operation name: arrayjoin.

Returns an image handle.

Required inputs: - input → :in (seqable of image): Array of input images

Optional inputs: - across → :across (integer): Number of images across grid - shim → :shim (integer): Pixels between images - background → :background (seqable of number): Colour for new pixels - halign → :halign (keyword, see ol.vips.enums/align): Align on the left, centre or right - valign → :valign (keyword, see ol.vips.enums/align): Align on the top, centre or bottom - hspacing → :hspacing (integer): Horizontal spacing between images - vspacing → :vspacing (integer): Vertical spacing between images

Outputs: - out → :out (image): Output image

autorotate image by exif tag

Operation name: autorot.

Returns a closeable result map. Pass it anywhere an image is expected, or inspect :out and the additional outputs directly.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image - angle → :angle (keyword, see ol.vips.enums/angle): Angle image was rotated by - flip → :flip (boolean): Whether the image was flipped or not

find image average

Operation name: avg.

Returns a closeable result map. Pass it anywhere an image is expected, or inspect :out and the additional outputs directly.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (float): Output value

boolean operation across image bands

Operation name: bandbool.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - boolean → :boolean (keyword, see ol.vips.enums/operation-boolean): Boolean to perform

Optional inputs: - none

Outputs: - out → :out (image): Output image

fold up x axis into bands

Operation name: bandfold.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - factor → :factor (integer): Fold by this factor

Outputs: - out → :out (image): Output image

bandwise join a set of images

Operation name: bandjoin.

Returns an image handle.

Required inputs: - input → :in (seqable of image): Array of input images

Optional inputs: - none

Outputs: - out → :out (image): Output image

append a constant band to an image

Operation name: bandjoin_const.

Returns an image handle.

Required inputs: - input → :in (image): Input image - c → :c (seqable of number): Array of constants to add

Optional inputs: - none

Outputs: - out → :out (image): Output image

band-wise average

Operation name: bandmean.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument

Optional inputs: - none

Outputs: - out → :out (image): Output image

band-wise rank of a set of images

Operation name: bandrank.

Returns an image handle.

Required inputs: - input → :in (seqable of image): Array of input images

Optional inputs: - index → :index (integer): Select this band element from sorted list

Outputs: - out → :out (image): Output image

unfold image bands into x axis

Operation name: bandunfold.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - factor → :factor (integer): Unfold by this factor

Outputs: - out → :out (image): Output image

make a black image

Operation name: black.

Returns an image handle.

Required inputs: - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels

Optional inputs: - bands → :bands (integer): Number of bands in image

Outputs: - out → :out (image): Output image

boolean operation on two images

Operation name: boolean.

Returns an image handle.

Required inputs: - left → :left (image): Left-hand image argument - right → :right (image): Right-hand image argument - boolean → :boolean (keyword, see ol.vips.enums/operation-boolean): Boolean to perform

Optional inputs: - none

Outputs: - out → :out (image): Output image

boolean operations against a constant

Operation name: boolean_const.

Returns an image handle.

Required inputs: - input → :in (image): Input image - boolean → :boolean (keyword, see ol.vips.enums/operation-boolean): Boolean to perform - c → :c (seqable of number): Array of constants

Optional inputs: - none

Outputs: - out → :out (image): Output image

build a look-up table

Operation name: buildlut.

Returns an image handle.

Required inputs: - input → :in (image): Matrix of XY coordinates

Optional inputs: - none

Outputs: - out → :out (image): Output image

byteswap an image

Operation name: byteswap.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

cache an image

Operation name: cache.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - max-tiles → :max-tiles (integer): Maximum number of tiles to cache - tile-height → :tile-height (integer): Tile height in pixels - tile-width → :tile-width (integer): Tile width in pixels

Outputs: - out → :out (image): Output image

Canny edge detector

Operation name: canny.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - sigma → :sigma (float): Sigma of Gaussian - precision → :precision (keyword, see ol.vips.enums/precision): Convolve with this precision

Outputs: - out → :out (image): Output image

use pixel values to pick cases from an array of images

Operation name: case.

Returns an image handle.

Required inputs: - index → :index (image): Index image - cases → :cases (seqable of image): Array of case images

Optional inputs: - none

Outputs: - out → :out (image): Output image

cast an image

Operation name: cast.

Returns an image handle.

Required inputs: - input → :in (image): Input image - format → :format (keyword, see ol.vips.enums/band-format): Format to cast to

Optional inputs: - shift → :shift (boolean): Shift integer values up and down

Outputs: - out → :out (image): Output image

clamp values of an image

Operation name: clamp.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - min → :min (float): Minimum value - max → :max (float): Maximum value

Outputs: - out → :out (image): Output image

transform LCh to CMC

Operation name: CMC2LCh.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

transform CMYK to XYZ

Operation name: CMYK2XYZ.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

convert to a new colorspace

Operation name: colourspace.

Returns an image handle.

Required inputs: - input → :in (image): Input image - space → :space (keyword, see ol.vips.enums/interpretation): Destination color space

Optional inputs: - source-space → :source-space (keyword, see ol.vips.enums/interpretation): Source color space

Outputs: - out → :out (image): Output image

convolve with rotating mask

Operation name: compass.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - mask → :mask (image): Input matrix image

Optional inputs: - times → :times (integer): Rotate and convolve this many times - angle → :angle (keyword, see ol.vips.enums/angle45): Rotate mask by this much between convolutions - combine → :combine (keyword, see ol.vips.enums/combine): Combine convolution results like this - precision → :precision (keyword, see ol.vips.enums/precision): Convolve with this precision - layers → :layers (integer): Use this many layers in approximation - cluster → :cluster (integer): Cluster lines closer than this in approximation

Outputs: - out → :out (image): Output image

perform a complex operation on an image

Operation name: complex.

Returns an image handle.

Required inputs: - input → :in (image): Input image - cmplx → :cmplx (keyword, see ol.vips.enums/operation-complex): Complex to perform

Optional inputs: - none

Outputs: - out → :out (image): Output image

complex binary operations on two images

Operation name: complex2.

Returns an image handle.

Required inputs: - left → :left (image): Left-hand image argument - right → :right (image): Right-hand image argument - cmplx → :cmplx (keyword, see ol.vips.enums/operation-complex2): Binary complex operation to perform

Optional inputs: - none

Outputs: - out → :out (image): Output image

form a complex image from two real images

Operation name: complexform.

Returns an image handle.

Required inputs: - left → :left (image): Left-hand image argument - right → :right (image): Right-hand image argument

Optional inputs: - none

Outputs: - out → :out (image): Output image

get a component from a complex image

Operation name: complexget.

Returns an image handle.

Required inputs: - input → :in (image): Input image - get → :get (keyword, see ol.vips.enums/operation-complexget): Complex to perform

Optional inputs: - none

Outputs: - out → :out (image): Output image

blend a pair of images with a blend mode

Operation name: composite2.

Returns an image handle.

Required inputs: - base → :base (image): Base image - overlay → :overlay (image): Overlay image - mode → :mode (keyword, see ol.vips.enums/blend-mode): VipsBlendMode to join with

Optional inputs: - x → :x (integer): x position of overlay - y → :y (integer): y position of overlay - compositing-space → :compositing-space (keyword, see ol.vips.enums/interpretation): Composite images in this colour space - premultiplied → :premultiplied (boolean): Images have premultiplied alpha

Outputs: - out → :out (image): Output image

convolution operation

Operation name: conv.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - mask → :mask (image): Input matrix image

Optional inputs: - precision → :precision (keyword, see ol.vips.enums/precision): Convolve with this precision - layers → :layers (integer): Use this many layers in approximation - cluster → :cluster (integer): Cluster lines closer than this in approximation

Outputs: - out → :out (image): Output image

approximate integer convolution

Operation name: conva.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - mask → :mask (image): Input matrix image

Optional inputs: - layers → :layers (integer): Use this many layers in approximation - cluster → :cluster (integer): Cluster lines closer than this in approximation

Outputs: - out → :out (image): Output image

approximate separable integer convolution

Operation name: convasep.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - mask → :mask (image): Input matrix image

Optional inputs: - layers → :layers (integer): Use this many layers in approximation

Outputs: - out → :out (image): Output image

float convolution operation

Operation name: convf.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - mask → :mask (image): Input matrix image

Optional inputs: - none

Outputs: - out → :out (image): Output image

int convolution operation

Operation name: convi.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - mask → :mask (image): Input matrix image

Optional inputs: - none

Outputs: - out → :out (image): Output image

separable convolution operation

Operation name: convsep.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - mask → :mask (image): Input matrix image

Optional inputs: - precision → :precision (keyword, see ol.vips.enums/precision): Convolve with this precision - layers → :layers (integer): Use this many layers in approximation - cluster → :cluster (integer): Cluster lines closer than this in approximation

Outputs: - out → :out (image): Output image

copy an image

Operation name: copy.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - swap → :swap (boolean): Swap bytes in image between little and big-endian - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels - bands → :bands (integer): Number of bands in image - format → :format (keyword, see ol.vips.enums/band-format): Pixel format in image - coding → :coding (keyword, see ol.vips.enums/coding): Pixel coding - interpretation → :interpretation (keyword, see ol.vips.enums/interpretation): Pixel interpretation - xres → :xres (float): Horizontal resolution in pixels/mm - yres → :yres (float): Vertical resolution in pixels/mm - xoffset → :xoffset (integer): Horizontal offset of origin - yoffset → :yoffset (integer): Vertical offset of origin

Outputs: - out → :out (image): Output image

count lines in an image

Operation name: countlines.

Returns a result map.

Required inputs: - input → :in (image): Input image argument - direction → :direction (keyword, see ol.vips.enums/direction): Countlines left-right or up-down

Optional inputs: - none

Outputs: - nolines → :nolines (float): Number of lines

load csv

Operation name: csvload.

Returns a closeable result map. Pass it anywhere an image is expected, or inspect :out and the additional outputs directly.

Required inputs: - filename → :filename (string): Filename to load from

Optional inputs: - skip → :skip (integer): Skip this many lines at the start of the file - lines → :lines (integer): Read this many lines from the file - whitespace → :whitespace (string): Set of whitespace characters - separator → :separator (string): Set of separator characters - memory → :memory (boolean): Force open via memory - access → :access (keyword, see ol.vips.enums/access): Required access pattern for this file - fail-on → :fail-on (keyword, see ol.vips.enums/fail-on): Error level to fail on - revalidate → :revalidate (boolean): Don’t use a cached result for this operation - sequential → :sequential (boolean): Sequential read only - fail → :fail (boolean): Fail on first warning - disc → :disc (boolean): Open to disc

Outputs: - out → :out (image): Output image - flags → :flags (integer flags): Flags for this file

save image to csv

Operation name: csvsave.

Returns a result map.

Required inputs: - input → :in (image): Image to save - filename → :filename (string): Filename to save to

Optional inputs: - separator → :separator (string): Separator characters - keep → :keep (integer flags): Which metadata to retain - background → :background (seqable of number): Background value - page-height → :page-height (integer): Set page height for multipage save - profile → :profile (string): Filename of ICC profile to embed - strip → :strip (boolean): Strip all metadata from image

Outputs: - none

calculate dE00

Operation name: dE00.

Returns an image handle.

Required inputs: - left → :left (image): Left-hand input image - right → :right (image): Right-hand input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

calculate dE76

Operation name: dE76.

Returns an image handle.

Required inputs: - left → :left (image): Left-hand input image - right → :right (image): Right-hand input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

calculate dECMC

Operation name: dECMC.

Returns an image handle.

Required inputs: - left → :left (image): Left-hand input image - right → :right (image): Right-hand input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

find image standard deviation

Operation name: deviate.

Returns a closeable result map. Pass it anywhere an image is expected, or inspect :out and the additional outputs directly.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (float): Output value

divide two images

Operation name: divide.

Returns an image handle.

Required inputs: - left → :left (image): Left-hand image argument - right → :right (image): Right-hand image argument

Optional inputs: - none

Outputs: - out → :out (image): Output image

draw a circle on an image

Operation name: draw_circle.

Returns a result map.

Required inputs: - image → :image (image): Image to draw on - ink → :ink (seqable of number): Color for pixels - cx → :cx (integer): Centre of draw_circle - cy → :cy (integer): Centre of draw_circle - radius → :radius (integer): Radius in pixels

Optional inputs: - fill → :fill (boolean): Draw a solid object

Outputs: - none

flood-fill an area

Operation name: draw_flood.

Returns a result map.

Required inputs: - image → :image (image): Image to draw on - ink → :ink (seqable of number): Color for pixels - x → :x (integer): DrawFlood start point - y → :y (integer): DrawFlood start point

Optional inputs: - test → :test (image): Test pixels in this image - equal → :equal (boolean): DrawFlood while equal to edge

Outputs: - left → :left (integer): Left edge of modified area - top → :top (integer): Top edge of modified area - width → :width (integer): Width of modified area - height → :height (integer): Height of modified area

paint an image into another image

Operation name: draw_image.

Returns a result map.

Required inputs: - image → :image (image): Image to draw on - sub → :sub (image): Sub-image to insert into main image - x → :x (integer): Draw image here - y → :y (integer): Draw image here

Optional inputs: - mode → :mode (keyword, see ol.vips.enums/combine-mode): Combining mode

Outputs: - none

draw a line on an image

Operation name: draw_line.

Returns a result map.

Required inputs: - image → :image (image): Image to draw on - ink → :ink (seqable of number): Color for pixels - x1 → :x1 (integer): Start of draw_line - y1 → :y1 (integer): Start of draw_line - x2 → :x2 (integer): End of draw_line - y2 → :y2 (integer): End of draw_line

Optional inputs: - none

Outputs: - none

draw a mask on an image

Operation name: draw_mask.

Returns a result map.

Required inputs: - image → :image (image): Image to draw on - ink → :ink (seqable of number): Color for pixels - mask → :mask (image): Mask of pixels to draw - x → :x (integer): Draw mask here - y → :y (integer): Draw mask here

Optional inputs: - none

Outputs: - none

paint a rectangle on an image

Operation name: draw_rect.

Returns a result map.

Required inputs: - image → :image (image): Image to draw on - ink → :ink (seqable of number): Color for pixels - left → :left (integer): Rect to fill - top → :top (integer): Rect to fill - width → :width (integer): Rect to fill - height → :height (integer): Rect to fill

Optional inputs: - fill → :fill (boolean): Draw a solid object

Outputs: - none

blur a rectangle on an image

Operation name: draw_smudge.

Returns a result map.

Required inputs: - image → :image (image): Image to draw on - left → :left (integer): Rect to fill - top → :top (integer): Rect to fill - width → :width (integer): Rect to fill - height → :height (integer): Rect to fill

Optional inputs: - none

Outputs: - none

save image to deepzoom file

Operation name: dzsave.

Returns a result map.

Required inputs: - input → :in (image): Image to save - filename → :filename (string): Filename to save to

Optional inputs: - dirname → :dirname (string): Directory name to save to - imagename → :imagename (string): Image name - layout → :layout (keyword, see ol.vips.enums/foreign-dz-layout): Directory layout - suffix → :suffix (string): Filename suffix for tiles - overlap → :overlap (integer): Tile overlap in pixels - tile-size → :tile-size (integer): Tile size in pixels - tile-height → :tile-height (integer): Tile height in pixels - tile-width → :tile-width (integer): Tile width in pixels - centre → :centre (boolean): Center image in tile - depth → :depth (keyword, see ol.vips.enums/foreign-dz-depth): Pyramid depth - angle → :angle (keyword, see ol.vips.enums/angle): Rotate image during save - container → :container (keyword, see ol.vips.enums/foreign-dz-container): Pyramid container type - properties → :properties (boolean): Write a properties file to the output directory - compression → :compression (integer): ZIP deflate compression level - region-shrink → :region-shrink (keyword, see ol.vips.enums/region-shrink): Method to shrink regions - skip-blanks → :skip-blanks (integer): Skip tiles which are nearly equal to the background - id → :id (string): Resource ID - q → :Q (integer): Q factor - no-strip → :no-strip (boolean): Don’t strip tile metadata - basename → :basename (string): Base name to save to - keep → :keep (integer flags): Which metadata to retain - background → :background (seqable of number): Background value - page-height → :page-height (integer): Set page height for multipage save - profile → :profile (string): Filename of ICC profile to embed - strip → :strip (boolean): Strip all metadata from image

Outputs: - none

embed an image in a larger image

Operation name: embed.

Returns an image handle.

Required inputs: - input → :in (image): Input image - x → :x (integer): Left edge of input in output - y → :y (integer): Top edge of input in output - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels

Optional inputs: - extend → :extend (keyword, see ol.vips.enums/extend): How to generate the extra pixels - background → :background (seqable of number): Color for background pixels

Outputs: - out → :out (image): Output image

extract an area from an image

Operation name: extract_area.

Returns an image handle.

Required inputs: - input → :input (image): Input image - left → :left (integer): Left edge of extract area - top → :top (integer): Top edge of extract area - width → :width (integer): Width of extract area - height → :height (integer): Height of extract area

Optional inputs: - none

Outputs: - out → :out (image): Output image

extract band from an image

Operation name: extract_band.

Returns an image handle.

Required inputs: - input → :in (image): Input image - band → :band (integer): Band to extract

Optional inputs: - n → :n (integer): Number of bands to extract

Outputs: - out → :out (image): Output image

make an image showing the eye’s spatial response

Operation name: eye.

Returns an image handle.

Required inputs: - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels

Optional inputs: - uchar → :uchar (boolean): Output an unsigned char image - factor → :factor (float): Maximum spatial frequency

Outputs: - out → :out (image): Output image

false-color an image

Operation name: falsecolour.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

fast correlation

Operation name: fastcor.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - ref → :ref (image): Input reference image

Optional inputs: - none

Outputs: - out → :out (image): Output image

fill image zeros with nearest non-zero pixel

Operation name: fill_nearest.

Returns a closeable result map. Pass it anywhere an image is expected, or inspect :out and the additional outputs directly.

Required inputs: - input → :in (image): Input image argument

Optional inputs: - none

Outputs: - out → :out (image): Value of nearest non-zero pixel - distance → :distance (image): Distance to nearest non-zero pixel

search an image for non-edge areas

Operation name: find_trim.

Returns a result map.

Required inputs: - input → :in (image): Image to find_trim

Optional inputs: - threshold → :threshold (float): Object threshold - background → :background (seqable of number): Color for background pixels - line-art → :line-art (boolean): Enable line art mode

Outputs: - left → :left (integer): Left edge of image - top → :top (integer): Top edge of extract area - width → :width (integer): Width of extract area - height → :height (integer): Height of extract area

flatten alpha out of an image

Operation name: flatten.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - background → :background (seqable of number): Background value - max-alpha → :max-alpha (float): Maximum value of alpha channel

Outputs: - out → :out (image): Output image

flip an image

Operation name: flip.

Returns an image handle.

Required inputs: - input → :in (image): Input image - direction → :direction (keyword, see ol.vips.enums/direction): Direction to flip image

Optional inputs: - none

Outputs: - out → :out (image): Output image

transform float RGB to Radiance coding

Operation name: float2rad.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

make a fractal surface

Operation name: fractsurf.

Returns an image handle.

Required inputs: - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels - fractal-dimension → :fractal-dimension (float): Fractal dimension

Optional inputs: - none

Outputs: - out → :out (image): Output image

frequency-domain filtering

Operation name: freqmult.

Returns an image handle.

Required inputs: - input → :in (image): Input image - mask → :mask (image): Input mask image

Optional inputs: - none

Outputs: - out → :out (image): Output image

gamma an image

Operation name: gamma.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - exponent → :exponent (float): Gamma factor

Outputs: - out → :out (image): Output image

gaussian blur

Operation name: gaussblur.

Returns an image handle.

Required inputs: - input → :in (image): Input image - sigma → :sigma (float): Sigma of Gaussian

Optional inputs: - min-ampl → :min-ampl (float): Minimum amplitude of Gaussian - precision → :precision (keyword, see ol.vips.enums/precision): Convolve with this precision

Outputs: - out → :out (image): Output image

make a gaussian image

Operation name: gaussmat.

Returns an image handle.

Required inputs: - sigma → :sigma (float): Sigma of Gaussian - min-ampl → :min-ampl (float): Minimum amplitude of Gaussian

Optional inputs: - separable → :separable (boolean): Generate separable Gaussian - integer → :integer (boolean): Generate integer Gaussian - precision → :precision (keyword, see ol.vips.enums/precision): Generate with this precision

Outputs: - out → :out (image): Output image

make a gaussnoise image

Operation name: gaussnoise.

Returns an image handle.

Required inputs: - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels

Optional inputs: - sigma → :sigma (float): Standard deviation of pixels in generated image - mean → :mean (float): Mean of pixels in generated image - seed → :seed (integer): Random number seed

Outputs: - out → :out (image): Output image

load GIF with libnsgif

Operation name: gifload.

Returns a closeable result map. Pass it anywhere an image is expected, or inspect :out and the additional outputs directly.

Required inputs: - filename → :filename (string): Filename to load from

Optional inputs: - n → :n (integer): Number of pages to load, -1 for all - page → :page (integer): First page to load - memory → :memory (boolean): Force open via memory - access → :access (keyword, see ol.vips.enums/access): Required access pattern for this file - fail-on → :fail-on (keyword, see ol.vips.enums/fail-on): Error level to fail on - revalidate → :revalidate (boolean): Don’t use a cached result for this operation - sequential → :sequential (boolean): Sequential read only - fail → :fail (boolean): Fail on first warning - disc → :disc (boolean): Open to disc

Outputs: - out → :out (image): Output image - flags → :flags (integer flags): Flags for this file

save as gif

Operation name: gifsave.

Returns a result map.

Required inputs: - input → :in (image): Image to save - filename → :filename (string): Filename to save to

Optional inputs: - dither → :dither (float): Amount of dithering - effort → :effort (integer): Quantisation effort - bitdepth → :bitdepth (integer): Number of bits per pixel - interframe-maxerror → :interframe-maxerror (float): Maximum inter-frame error for transparency - reuse → :reuse (boolean): Reuse palette from input - interpalette-maxerror → :interpalette-maxerror (float): Maximum inter-palette error for palette reusage - interlace → :interlace (boolean): Generate an interlaced (progressive) GIF - reoptimise → :reoptimise (boolean): Reoptimise colour palettes - keep-duplicate-frames → :keep-duplicate-frames (boolean): Keep duplicate frames in the output instead of combining them - keep → :keep (integer flags): Which metadata to retain - background → :background (seqable of number): Background value - page-height → :page-height (integer): Set page height for multipage save - profile → :profile (string): Filename of ICC profile to embed - strip → :strip (boolean): Strip all metadata from image

Outputs: - none

global balance an image mosaic

Operation name: globalbalance.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - gamma → :gamma (float): Image gamma - int-output → :int-output (boolean): Integer output

Outputs: - out → :out (image): Output image

place an image within a larger image with a certain gravity

Operation name: gravity.

Returns an image handle.

Required inputs: - input → :in (image): Input image - direction → :direction (keyword, see ol.vips.enums/compass-direction): Direction to place image within width/height - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels

Optional inputs: - extend → :extend (keyword, see ol.vips.enums/extend): How to generate the extra pixels - background → :background (seqable of number): Color for background pixels

Outputs: - out → :out (image): Output image

make a grey ramp image

Operation name: grey.

Returns an image handle.

Required inputs: - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels

Optional inputs: - uchar → :uchar (boolean): Output an unsigned char image

Outputs: - out → :out (image): Output image

grid an image

Operation name: grid.

Returns an image handle.

Required inputs: - input → :in (image): Input image - tile-height → :tile-height (integer): Chop into tiles this high - across → :across (integer): Number of tiles across - down → :down (integer): Number of tiles down

Optional inputs: - none

Outputs: - out → :out (image): Output image

load a HEIF image

Operation name: heifload.

Returns a closeable result map. Pass it anywhere an image is expected, or inspect :out and the additional outputs directly.

Required inputs: - filename → :filename (string): Filename to load from

Optional inputs: - page → :page (integer): First page to load - n → :n (integer): Number of pages to load, -1 for all - thumbnail → :thumbnail (boolean): Fetch thumbnail image - autorotate → :autorotate (boolean): Rotate image using exif orientation - unlimited → :unlimited (boolean): Remove all denial of service limits - memory → :memory (boolean): Force open via memory - access → :access (keyword, see ol.vips.enums/access): Required access pattern for this file - fail-on → :fail-on (keyword, see ol.vips.enums/fail-on): Error level to fail on - revalidate → :revalidate (boolean): Don’t use a cached result for this operation - sequential → :sequential (boolean): Sequential read only - fail → :fail (boolean): Fail on first warning - disc → :disc (boolean): Open to disc

Outputs: - out → :out (image): Output image - flags → :flags (integer flags): Flags for this file

save image in HEIF format

Operation name: heifsave.

Returns a result map.

Required inputs: - input → :in (image): Image to save - filename → :filename (string): Filename to save to

Optional inputs: - q → :Q (integer): Q factor - bitdepth → :bitdepth (integer): Number of bits per pixel - lossless → :lossless (boolean): Enable lossless compression - compression → :compression (keyword, see ol.vips.enums/foreign-heif-compression): Compression format - effort → :effort (integer): CPU effort - subsample-mode → :subsample-mode (keyword, see ol.vips.enums/foreign-subsample): Select chroma subsample operation mode - speed → :speed (integer): CPU effort - encoder → :encoder (keyword, see ol.vips.enums/foreign-heif-encoder): Select encoder to use - keep → :keep (integer flags): Which metadata to retain - background → :background (seqable of number): Background value - page-height → :page-height (integer): Set page height for multipage save - profile → :profile (string): Filename of ICC profile to embed - strip → :strip (boolean): Strip all metadata from image

Outputs: - none

form cumulative histogram

Operation name: hist_cum.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

estimate image entropy

Operation name: hist_entropy.

Returns a closeable result map. Pass it anywhere an image is expected, or inspect :out and the additional outputs directly.

Required inputs: - input → :in (image): Input histogram image

Optional inputs: - none

Outputs: - out → :out (float): Output value

histogram equalisation

Operation name: hist_equal.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - band → :band (integer): Equalise with this band

Outputs: - out → :out (image): Output image

find image histogram

Operation name: hist_find.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - band → :band (integer): Find histogram of band

Outputs: - out → :out (image): Output histogram

find indexed image histogram

Operation name: hist_find_indexed.

Returns an image handle.

Required inputs: - input → :in (image): Input image - index → :index (image): Index image

Optional inputs: - combine → :combine (keyword, see ol.vips.enums/combine): Combine bins like this

Outputs: - out → :out (image): Output histogram

find n-dimensional image histogram

Operation name: hist_find_ndim.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - bins → :bins (integer): Number of bins in each dimension

Outputs: - out → :out (image): Output histogram

test for monotonicity

Operation name: hist_ismonotonic.

Returns a result map.

Required inputs: - input → :in (image): Input histogram image

Optional inputs: - none

Outputs: - monotonic → :monotonic (boolean): true if in is monotonic

local histogram equalisation

Operation name: hist_local.

Returns an image handle.

Required inputs: - input → :in (image): Input image - width → :width (integer): Window width in pixels - height → :height (integer): Window height in pixels

Optional inputs: - max-slope → :max-slope (integer): Maximum slope (CLAHE)

Outputs: - out → :out (image): Output image

match two histograms

Operation name: hist_match.

Returns an image handle.

Required inputs: - input → :in (image): Input histogram - ref → :ref (image): Reference histogram

Optional inputs: - none

Outputs: - out → :out (image): Output image

normalise histogram

Operation name: hist_norm.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

plot histogram

Operation name: hist_plot.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

find hough circle transform

Operation name: hough_circle.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - scale → :scale (integer): Scale down dimensions by this factor - min-radius → :min-radius (integer): Smallest radius to search for - max-radius → :max-radius (integer): Largest radius to search for

Outputs: - out → :out (image): Output image

find hough line transform

Operation name: hough_line.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - width → :width (integer): Horizontal size of parameter space - height → :height (integer): Vertical size of parameter space

Outputs: - out → :out (image): Output image

transform HSV to sRGB

Operation name: HSV2sRGB.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

output to device with ICC profile

Operation name: icc_export.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - pcs → :pcs (keyword, see ol.vips.enums/pcs): Set Profile Connection Space - intent → :intent (keyword, see ol.vips.enums/intent): Rendering intent - black-point-compensation → :black-point-compensation (boolean): Enable black point compensation - output-profile → :output-profile (string): Filename to load output profile from - depth → :depth (integer): Output device space depth in bits

Outputs: - out → :out (image): Output image

import from device with ICC profile

Operation name: icc_import.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - pcs → :pcs (keyword, see ol.vips.enums/pcs): Set Profile Connection Space - intent → :intent (keyword, see ol.vips.enums/intent): Rendering intent - black-point-compensation → :black-point-compensation (boolean): Enable black point compensation - embedded → :embedded (boolean): Use embedded input profile, if available - input-profile → :input-profile (string): Filename to load input profile from

Outputs: - out → :out (image): Output image

transform between devices with ICC profiles

Operation name: icc_transform.

Returns an image handle.

Required inputs: - input → :in (image): Input image - output-profile → :output-profile (string): Filename to load output profile from

Optional inputs: - pcs → :pcs (keyword, see ol.vips.enums/pcs): Set Profile Connection Space - intent → :intent (keyword, see ol.vips.enums/intent): Rendering intent - black-point-compensation → :black-point-compensation (boolean): Enable black point compensation - embedded → :embedded (boolean): Use embedded input profile, if available - input-profile → :input-profile (string): Filename to load input profile from - depth → :depth (integer): Output device space depth in bits

Outputs: - out → :out (image): Output image

make a 1D image where pixel values are indexes

Operation name: identity.

Returns an image handle.

Required inputs: - none

Optional inputs: - bands → :bands (integer): Number of bands in LUT - ushort → :ushort (boolean): Create a 16-bit LUT - size → :size (integer): Size of 16-bit LUT

Outputs: - out → :out (image): Output image

ifthenelse an image

Operation name: ifthenelse.

Returns an image handle.

Required inputs: - cond → :cond (image): Condition input image - in1 → :in1 (image): Source for TRUE pixels - in2 → :in2 (image): Source for FALSE pixels

Optional inputs: - blend → :blend (boolean): Blend smoothly between then and else parts

Outputs: - out → :out (image): Output image

insert image @sub into @main at @x, @y

Operation name: insert.

Returns an image handle.

Required inputs: - main → :main (image): Main input image - sub → :sub (image): Sub-image to insert into main image - x → :x (integer): Left edge of sub in main - y → :y (integer): Top edge of sub in main

Optional inputs: - expand → :expand (boolean): Expand output to hold all of both inputs - background → :background (seqable of number): Color for new pixels

Outputs: - out → :out (image): Output image

invert an image

Operation name: invert.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

build an inverted look-up table

Operation name: invertlut.

Returns an image handle.

Required inputs: - input → :in (image): Matrix of XY coordinates

Optional inputs: - size → :size (integer): LUT size to generate

Outputs: - out → :out (image): Output image

join a pair of images

Operation name: join.

Returns an image handle.

Required inputs: - in1 → :in1 (image): First input image - in2 → :in2 (image): Second input image - direction → :direction (keyword, see ol.vips.enums/direction): Join left-right or up-down

Optional inputs: - expand → :expand (boolean): Expand output to hold all of both inputs - shim → :shim (integer): Pixels between images - background → :background (seqable of number): Colour for new pixels - align → :align (keyword, see ol.vips.enums/align): Align on the low, centre or high coordinate edge

Outputs: - out → :out (image): Output image

load jpeg from file

Operation name: jpegload.

Returns a closeable result map. Pass it anywhere an image is expected, or inspect :out and the additional outputs directly.

Required inputs: - filename → :filename (string): Filename to load from

Optional inputs: - shrink → :shrink (integer): Shrink factor on load - autorotate → :autorotate (boolean): Rotate image using exif orientation - unlimited → :unlimited (boolean): Remove all denial of service limits - memory → :memory (boolean): Force open via memory - access → :access (keyword, see ol.vips.enums/access): Required access pattern for this file - fail-on → :fail-on (keyword, see ol.vips.enums/fail-on): Error level to fail on - revalidate → :revalidate (boolean): Don’t use a cached result for this operation - sequential → :sequential (boolean): Sequential read only - fail → :fail (boolean): Fail on first warning - disc → :disc (boolean): Open to disc

Outputs: - out → :out (image): Output image - flags → :flags (integer flags): Flags for this file

save image to jpeg file

Operation name: jpegsave.

Returns a result map.

Required inputs: - input → :in (image): Image to save - filename → :filename (string): Filename to save to

Optional inputs: - q → :Q (integer): Q factor - optimize-coding → :optimize-coding (boolean): Compute optimal Huffman coding tables - interlace → :interlace (boolean): Generate an interlaced (progressive) jpeg - no-subsample → :no-subsample (boolean): Disable chroma subsample - trellis-quant → :trellis-quant (boolean): Apply trellis quantisation to each 8x8 block - overshoot-deringing → :overshoot-deringing (boolean): Apply overshooting to samples with extreme values - optimize-scans → :optimize-scans (boolean): Split spectrum of DCT coefficients into separate scans - quant-table → :quant-table (integer): Use predefined quantization table with given index - subsample-mode → :subsample-mode (keyword, see ol.vips.enums/foreign-subsample): Select chroma subsample operation mode - restart-interval → :restart-interval (integer): Add restart markers every specified number of mcu - keep → :keep (integer flags): Which metadata to retain - background → :background (seqable of number): Background value - page-height → :page-height (integer): Set page height for multipage save - profile → :profile (string): Filename of ICC profile to embed - strip → :strip (boolean): Strip all metadata from image

Outputs: - none

save image to jpeg mime

Operation name: jpegsave_mime.

Returns a result map.

Required inputs: - input → :in (image): Image to save

Optional inputs: - q → :Q (integer): Q factor - optimize-coding → :optimize-coding (boolean): Compute optimal Huffman coding tables - interlace → :interlace (boolean): Generate an interlaced (progressive) jpeg - no-subsample → :no-subsample (boolean): Disable chroma subsample - trellis-quant → :trellis-quant (boolean): Apply trellis quantisation to each 8x8 block - overshoot-deringing → :overshoot-deringing (boolean): Apply overshooting to samples with extreme values - optimize-scans → :optimize-scans (boolean): Split spectrum of DCT coefficients into separate scans - quant-table → :quant-table (integer): Use predefined quantization table with given index - subsample-mode → :subsample-mode (keyword, see ol.vips.enums/foreign-subsample): Select chroma subsample operation mode - restart-interval → :restart-interval (integer): Add restart markers every specified number of mcu - keep → :keep (integer flags): Which metadata to retain - background → :background (seqable of number): Background value - page-height → :page-height (integer): Set page height for multipage save - profile → :profile (string): Filename of ICC profile to embed - strip → :strip (boolean): Strip all metadata from image

Outputs: - none

unpack a LabQ image to float Lab

Operation name: LabQ2Lab.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

unpack a LabQ image to short Lab

Operation name: LabQ2LabS.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

convert a LabQ image to sRGB

Operation name: LabQ2sRGB.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

transform signed short Lab to float

Operation name: LabS2Lab.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

transform short Lab to LabQ coding

Operation name: LabS2LabQ.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

transform float Lab to LabQ coding

Operation name: Lab2LabQ.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

transform float Lab to signed short

Operation name: Lab2LabS.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

transform Lab to LCh

Operation name: Lab2LCh.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

transform CIELAB to XYZ

Operation name: Lab2XYZ.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - temp → :temp (seqable of number): Color temperature

Outputs: - out → :out (image): Output image

label regions in an image

Operation name: labelregions.

Returns a result map.

Required inputs: - input → :in (image): Input image argument

Optional inputs: - none

Outputs: - mask → :mask (image): Mask of region labels - segments → :segments (integer): Number of discrete contiguous regions

transform LCh to CMC

Operation name: LCh2CMC.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

transform LCh to Lab

Operation name: LCh2Lab.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

calculate (a * in + b)

Operation name: linear.

Returns an image handle.

Required inputs: - input → :in (image): Input image - a → :a (seqable of number): Multiply by this - b → :b (seqable of number): Add this

Optional inputs: - uchar → :uchar (boolean): Output should be uchar

Outputs: - out → :out (image): Output image

cache an image as a set of lines

Operation name: linecache.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - tile-height → :tile-height (integer): Tile height in pixels - access → :access (keyword, see ol.vips.enums/access): Expected access pattern - threaded → :threaded (boolean): Allow threaded access - persistent → :persistent (boolean): Keep cache between evaluations

Outputs: - out → :out (image): Output image

make a Laplacian of Gaussian image

Operation name: logmat.

Returns an image handle.

Required inputs: - sigma → :sigma (float): Radius of Gaussian - min-ampl → :min-ampl (float): Minimum amplitude of Gaussian

Optional inputs: - separable → :separable (boolean): Generate separable Gaussian - integer → :integer (boolean): Generate integer Gaussian - precision → :precision (keyword, see ol.vips.enums/precision): Generate with this precision

Outputs: - out → :out (image): Output image

resample with a map image

Operation name: mapim.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - index → :index (image): Index pixels with this

Optional inputs: - background → :background (seqable of number): Background value - premultiplied → :premultiplied (boolean): Images have premultiplied alpha - extend → :extend (keyword, see ol.vips.enums/extend): How to generate the extra pixels

Outputs: - out → :out (image): Output image

map an image though a lut

Operation name: maplut.

Returns an image handle.

Required inputs: - input → :in (image): Input image - lut → :lut (image): Look-up table image

Optional inputs: - band → :band (integer): Apply one-band lut to this band of in

Outputs: - out → :out (image): Output image

make a butterworth filter

Operation name: mask_butterworth.

Returns an image handle.

Required inputs: - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels - order → :order (float): Filter order - frequency-cutoff → :frequency-cutoff (float): Frequency cutoff - amplitude-cutoff → :amplitude-cutoff (float): Amplitude cutoff

Optional inputs: - uchar → :uchar (boolean): Output an unsigned char image - nodc → :nodc (boolean): Remove DC component - reject → :reject (boolean): Invert the sense of the filter - optical → :optical (boolean): Rotate quadrants to optical space

Outputs: - out → :out (image): Output image

make a butterworth_band filter

Operation name: mask_butterworth_band.

Returns an image handle.

Required inputs: - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels - order → :order (float): Filter order - frequency-cutoff-x → :frequency-cutoff-x (float): Frequency cutoff x - frequency-cutoff-y → :frequency-cutoff-y (float): Frequency cutoff y - radius → :radius (float): Radius of circle - amplitude-cutoff → :amplitude-cutoff (float): Amplitude cutoff

Optional inputs: - uchar → :uchar (boolean): Output an unsigned char image - nodc → :nodc (boolean): Remove DC component - reject → :reject (boolean): Invert the sense of the filter - optical → :optical (boolean): Rotate quadrants to optical space

Outputs: - out → :out (image): Output image

make a butterworth ring filter

Operation name: mask_butterworth_ring.

Returns an image handle.

Required inputs: - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels - order → :order (float): Filter order - frequency-cutoff → :frequency-cutoff (float): Frequency cutoff - amplitude-cutoff → :amplitude-cutoff (float): Amplitude cutoff - ringwidth → :ringwidth (float): Ringwidth

Optional inputs: - uchar → :uchar (boolean): Output an unsigned char image - nodc → :nodc (boolean): Remove DC component - reject → :reject (boolean): Invert the sense of the filter - optical → :optical (boolean): Rotate quadrants to optical space

Outputs: - out → :out (image): Output image

make fractal filter

Operation name: mask_fractal.

Returns an image handle.

Required inputs: - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels - fractal-dimension → :fractal-dimension (float): Fractal dimension

Optional inputs: - uchar → :uchar (boolean): Output an unsigned char image - nodc → :nodc (boolean): Remove DC component - reject → :reject (boolean): Invert the sense of the filter - optical → :optical (boolean): Rotate quadrants to optical space

Outputs: - out → :out (image): Output image

make a gaussian filter

Operation name: mask_gaussian.

Returns an image handle.

Required inputs: - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels - frequency-cutoff → :frequency-cutoff (float): Frequency cutoff - amplitude-cutoff → :amplitude-cutoff (float): Amplitude cutoff

Optional inputs: - uchar → :uchar (boolean): Output an unsigned char image - nodc → :nodc (boolean): Remove DC component - reject → :reject (boolean): Invert the sense of the filter - optical → :optical (boolean): Rotate quadrants to optical space

Outputs: - out → :out (image): Output image

make a gaussian filter

Operation name: mask_gaussian_band.

Returns an image handle.

Required inputs: - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels - frequency-cutoff-x → :frequency-cutoff-x (float): Frequency cutoff x - frequency-cutoff-y → :frequency-cutoff-y (float): Frequency cutoff y - radius → :radius (float): Radius of circle - amplitude-cutoff → :amplitude-cutoff (float): Amplitude cutoff

Optional inputs: - uchar → :uchar (boolean): Output an unsigned char image - nodc → :nodc (boolean): Remove DC component - reject → :reject (boolean): Invert the sense of the filter - optical → :optical (boolean): Rotate quadrants to optical space

Outputs: - out → :out (image): Output image

make a gaussian ring filter

Operation name: mask_gaussian_ring.

Returns an image handle.

Required inputs: - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels - frequency-cutoff → :frequency-cutoff (float): Frequency cutoff - amplitude-cutoff → :amplitude-cutoff (float): Amplitude cutoff - ringwidth → :ringwidth (float): Ringwidth

Optional inputs: - uchar → :uchar (boolean): Output an unsigned char image - nodc → :nodc (boolean): Remove DC component - reject → :reject (boolean): Invert the sense of the filter - optical → :optical (boolean): Rotate quadrants to optical space

Outputs: - out → :out (image): Output image

make an ideal filter

Operation name: mask_ideal.

Returns an image handle.

Required inputs: - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels - frequency-cutoff → :frequency-cutoff (float): Frequency cutoff

Optional inputs: - uchar → :uchar (boolean): Output an unsigned char image - nodc → :nodc (boolean): Remove DC component - reject → :reject (boolean): Invert the sense of the filter - optical → :optical (boolean): Rotate quadrants to optical space

Outputs: - out → :out (image): Output image

make an ideal band filter

Operation name: mask_ideal_band.

Returns an image handle.

Required inputs: - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels - frequency-cutoff-x → :frequency-cutoff-x (float): Frequency cutoff x - frequency-cutoff-y → :frequency-cutoff-y (float): Frequency cutoff y - radius → :radius (float): Radius of circle

Optional inputs: - uchar → :uchar (boolean): Output an unsigned char image - nodc → :nodc (boolean): Remove DC component - reject → :reject (boolean): Invert the sense of the filter - optical → :optical (boolean): Rotate quadrants to optical space

Outputs: - out → :out (image): Output image

make an ideal ring filter

Operation name: mask_ideal_ring.

Returns an image handle.

Required inputs: - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels - frequency-cutoff → :frequency-cutoff (float): Frequency cutoff - ringwidth → :ringwidth (float): Ringwidth

Optional inputs: - uchar → :uchar (boolean): Output an unsigned char image - nodc → :nodc (boolean): Remove DC component - reject → :reject (boolean): Invert the sense of the filter - optical → :optical (boolean): Rotate quadrants to optical space

Outputs: - out → :out (image): Output image

first-order match of two images

Operation name: match.

Returns an image handle.

Required inputs: - ref → :ref (image): Reference image - sec → :sec (image): Secondary image - xr1 → :xr1 (integer): Position of first reference tie-point - yr1 → :yr1 (integer): Position of first reference tie-point - xs1 → :xs1 (integer): Position of first secondary tie-point - ys1 → :ys1 (integer): Position of first secondary tie-point - xr2 → :xr2 (integer): Position of second reference tie-point - yr2 → :yr2 (integer): Position of second reference tie-point - xs2 → :xs2 (integer): Position of second secondary tie-point - ys2 → :ys2 (integer): Position of second secondary tie-point

Optional inputs: - hwindow → :hwindow (integer): Half window size - harea → :harea (integer): Half area size - search → :search (boolean): Search to improve tie-points

Outputs: - out → :out (image): Output image

apply a math operation to an image

Operation name: math.

Returns an image handle.

Required inputs: - input → :in (image): Input image - math → :math (keyword, see ol.vips.enums/operation-math): Math to perform

Optional inputs: - none

Outputs: - out → :out (image): Output image

binary math operations

Operation name: math2.

Returns an image handle.

Required inputs: - left → :left (image): Left-hand image argument - right → :right (image): Right-hand image argument - math2 → :math2 (keyword, see ol.vips.enums/operation-math2): Math to perform

Optional inputs: - none

Outputs: - out → :out (image): Output image

binary math operations with a constant

Operation name: math2_const.

Returns an image handle.

Required inputs: - input → :in (image): Input image - math2 → :math2 (keyword, see ol.vips.enums/operation-math2): Math to perform - c → :c (seqable of number): Array of constants

Optional inputs: - none

Outputs: - out → :out (image): Output image

invert a matrix

Operation name: matrixinvert.

Returns an image handle.

Required inputs: - input → :in (image): An square matrix

Optional inputs: - none

Outputs: - out → :out (image): Output matrix

load matrix

Operation name: matrixload.

Returns a closeable result map. Pass it anywhere an image is expected, or inspect :out and the additional outputs directly.

Required inputs: - filename → :filename (string): Filename to load from

Optional inputs: - memory → :memory (boolean): Force open via memory - access → :access (keyword, see ol.vips.enums/access): Required access pattern for this file - fail-on → :fail-on (keyword, see ol.vips.enums/fail-on): Error level to fail on - revalidate → :revalidate (boolean): Don’t use a cached result for this operation - sequential → :sequential (boolean): Sequential read only - fail → :fail (boolean): Fail on first warning - disc → :disc (boolean): Open to disc

Outputs: - out → :out (image): Output image - flags → :flags (integer flags): Flags for this file

multiply two matrices

Operation name: matrixmultiply.

Returns an image handle.

Required inputs: - left → :left (image): First matrix to multiply - right → :right (image): Second matrix to multiply

Optional inputs: - none

Outputs: - out → :out (image): Output matrix

print matrix

Operation name: matrixprint.

Returns a result map.

Required inputs: - input → :in (image): Image to save

Optional inputs: - keep → :keep (integer flags): Which metadata to retain - background → :background (seqable of number): Background value - page-height → :page-height (integer): Set page height for multipage save - profile → :profile (string): Filename of ICC profile to embed - strip → :strip (boolean): Strip all metadata from image

Outputs: - none

save image to matrix

Operation name: matrixsave.

Returns a result map.

Required inputs: - input → :in (image): Image to save - filename → :filename (string): Filename to save to

Optional inputs: - keep → :keep (integer flags): Which metadata to retain - background → :background (seqable of number): Background value - page-height → :page-height (integer): Set page height for multipage save - profile → :profile (string): Filename of ICC profile to embed - strip → :strip (boolean): Strip all metadata from image

Outputs: - none

maximum of a pair of images

Operation name: maxpair.

Returns an image handle.

Required inputs: - left → :left (image): Left-hand image argument - right → :right (image): Right-hand image argument

Optional inputs: - none

Outputs: - out → :out (image): Output image

measure a set of patches on a color chart

Operation name: measure.

Returns an image handle.

Required inputs: - input → :in (image): Image to measure - h → :h (integer): Number of patches across chart - v → :v (integer): Number of patches down chart

Optional inputs: - left → :left (integer): Left edge of extract area - top → :top (integer): Top edge of extract area - width → :width (integer): Width of extract area - height → :height (integer): Height of extract area

Outputs: - out → :out (image): Output array of statistics

merge two images

Operation name: merge.

Returns an image handle.

Required inputs: - ref → :ref (image): Reference image - sec → :sec (image): Secondary image - direction → :direction (keyword, see ol.vips.enums/direction): Horizontal or vertical merge - dx → :dx (integer): Horizontal displacement from sec to ref - dy → :dy (integer): Vertical displacement from sec to ref

Optional inputs: - mblend → :mblend (integer): Maximum blend size

Outputs: - out → :out (image): Output image

minimum of a pair of images

Operation name: minpair.

Returns an image handle.

Required inputs: - left → :left (image): Left-hand image argument - right → :right (image): Right-hand image argument

Optional inputs: - none

Outputs: - out → :out (image): Output image

morphology operation

Operation name: morph.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - mask → :mask (image): Input matrix image - morph → :morph (keyword, see ol.vips.enums/operation-morphology): Morphological operation to perform

Optional inputs: - none

Outputs: - out → :out (image): Output image

mosaic two images

Operation name: mosaic.

Returns a closeable result map. Pass it anywhere an image is expected, or inspect :out and the additional outputs directly.

Required inputs: - ref → :ref (image): Reference image - sec → :sec (image): Secondary image - direction → :direction (keyword, see ol.vips.enums/direction): Horizontal or vertical mosaic - xref → :xref (integer): Position of reference tie-point - yref → :yref (integer): Position of reference tie-point - xsec → :xsec (integer): Position of secondary tie-point - ysec → :ysec (integer): Position of secondary tie-point

Optional inputs: - hwindow → :hwindow (integer): Half window size - harea → :harea (integer): Half area size - mblend → :mblend (integer): Maximum blend size - bandno → :bandno (integer): Band to search for features on

Outputs: - out → :out (image): Output image - dx0 → :dx0 (integer): Detected integer offset - dy0 → :dy0 (integer): Detected integer offset - scale1 → :scale1 (float): Detected scale - angle1 → :angle1 (float): Detected rotation - dy1 → :dy1 (float): Detected first-order displacement - dx1 → :dx1 (float): Detected first-order displacement

first-order mosaic of two images

Operation name: mosaic1.

Returns an image handle.

Required inputs: - ref → :ref (image): Reference image - sec → :sec (image): Secondary image - direction → :direction (keyword, see ol.vips.enums/direction): Horizontal or vertical mosaic - xr1 → :xr1 (integer): Position of first reference tie-point - yr1 → :yr1 (integer): Position of first reference tie-point - xs1 → :xs1 (integer): Position of first secondary tie-point - ys1 → :ys1 (integer): Position of first secondary tie-point - xr2 → :xr2 (integer): Position of second reference tie-point - yr2 → :yr2 (integer): Position of second reference tie-point - xs2 → :xs2 (integer): Position of second secondary tie-point - ys2 → :ys2 (integer): Position of second secondary tie-point

Optional inputs: - hwindow → :hwindow (integer): Half window size - harea → :harea (integer): Half area size - search → :search (boolean): Search to improve tie-points - mblend → :mblend (integer): Maximum blend size - bandno → :bandno (integer): Band to search for features on

Outputs: - out → :out (image): Output image

pick most-significant byte from an image

Operation name: msb.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - band → :band (integer): Band to msb

Outputs: - out → :out (image): Output image

multiply two images

Operation name: multiply.

Returns an image handle.

Required inputs: - left → :left (image): Left-hand image argument - right → :right (image): Right-hand image argument

Optional inputs: - none

Outputs: - out → :out (image): Output image

find threshold for percent of pixels

Operation name: percent.

Returns a result map.

Required inputs: - input → :in (image): Input image - percent → :percent (float): Percent of pixels

Optional inputs: - none

Outputs: - threshold → :threshold (integer): Threshold above which lie percent of pixels

make a perlin noise image

Operation name: perlin.

Returns an image handle.

Required inputs: - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels

Optional inputs: - cell-size → :cell-size (integer): Size of Perlin cells - uchar → :uchar (boolean): Output an unsigned char image - seed → :seed (integer): Random number seed

Outputs: - out → :out (image): Output image

calculate phase correlation

Operation name: phasecor.

Returns an image handle.

Required inputs: - input → :in (image): Input image - in2 → :in2 (image): Second input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

load png from file

Operation name: pngload.

Returns a closeable result map. Pass it anywhere an image is expected, or inspect :out and the additional outputs directly.

Required inputs: - filename → :filename (string): Filename to load from

Optional inputs: - unlimited → :unlimited (boolean): Remove all denial of service limits - memory → :memory (boolean): Force open via memory - access → :access (keyword, see ol.vips.enums/access): Required access pattern for this file - fail-on → :fail-on (keyword, see ol.vips.enums/fail-on): Error level to fail on - revalidate → :revalidate (boolean): Don’t use a cached result for this operation - sequential → :sequential (boolean): Sequential read only - fail → :fail (boolean): Fail on first warning - disc → :disc (boolean): Open to disc

Outputs: - out → :out (image): Output image - flags → :flags (integer flags): Flags for this file

save image to file as PNG

Operation name: pngsave.

Returns a result map.

Required inputs: - input → :in (image): Image to save - filename → :filename (string): Filename to save to

Optional inputs: - compression → :compression (integer): Compression factor - interlace → :interlace (boolean): Interlace image - filter → :filter (integer flags): libspng row filter flag(s) - palette → :palette (boolean): Quantise to 8bpp palette - colours → :colours (integer): Max number of palette colours - q → :Q (integer): Quantisation quality - dither → :dither (float): Amount of dithering - bitdepth → :bitdepth (integer): Write as a 1, 2, 4, 8 or 16 bit image - effort → :effort (integer): Quantisation CPU effort - keep → :keep (integer flags): Which metadata to retain - background → :background (seqable of number): Background value - page-height → :page-height (integer): Set page height for multipage save - profile → :profile (string): Filename of ICC profile to embed - strip → :strip (boolean): Strip all metadata from image

Outputs: - none

premultiply image alpha

Operation name: premultiply.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - max-alpha → :max-alpha (float): Maximum value of alpha channel

Outputs: - out → :out (image): Output image

Prewitt edge detector

Operation name: prewitt.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

find image profiles

Operation name: profile.

Returns a result map.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - columns → :columns (image): First non-zero pixel in column - rows → :rows (image): First non-zero pixel in row

find image projections

Operation name: project.

Returns a result map.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - columns → :columns (image): Sums of columns - rows → :rows (image): Sums of rows

resample an image with a quadratic transform

Operation name: quadratic.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - coeff → :coeff (image): Coefficient matrix

Optional inputs: - none

Outputs: - out → :out (image): Output image

unpack Radiance coding to float RGB

Operation name: rad2float.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

rank filter

Operation name: rank.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - width → :width (integer): Window width in pixels - height → :height (integer): Window height in pixels - index → :index (integer): Select pixel at index

Optional inputs: - none

Outputs: - out → :out (image): Output image

load raw data from a file

Operation name: rawload.

Returns a closeable result map. Pass it anywhere an image is expected, or inspect :out and the additional outputs directly.

Required inputs: - filename → :filename (string): Filename to load from - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels - bands → :bands (integer): Number of bands in image

Optional inputs: - offset → :offset (integer): Offset in bytes from start of file - format → :format (keyword, see ol.vips.enums/band-format): Pixel format in image - interpretation → :interpretation (keyword, see ol.vips.enums/interpretation): Pixel interpretation - memory → :memory (boolean): Force open via memory - access → :access (keyword, see ol.vips.enums/access): Required access pattern for this file - fail-on → :fail-on (keyword, see ol.vips.enums/fail-on): Error level to fail on - revalidate → :revalidate (boolean): Don’t use a cached result for this operation - sequential → :sequential (boolean): Sequential read only - fail → :fail (boolean): Fail on first warning - disc → :disc (boolean): Open to disc

Outputs: - out → :out (image): Output image - flags → :flags (integer flags): Flags for this file

save image to raw file

Operation name: rawsave.

Returns a result map.

Required inputs: - input → :in (image): Image to save - filename → :filename (string): Filename to save to

Optional inputs: - keep → :keep (integer flags): Which metadata to retain - background → :background (seqable of number): Background value - page-height → :page-height (integer): Set page height for multipage save - profile → :profile (string): Filename of ICC profile to embed - strip → :strip (boolean): Strip all metadata from image

Outputs: - none

linear recombination with matrix

Operation name: recomb.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - m → :m (image): Matrix of coefficients

Optional inputs: - none

Outputs: - out → :out (image): Output image

reduce an image

Operation name: reduce.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - xshrink → :xshrink (float): Horizontal shrink factor - hshrink → :hshrink (float): Horizontal shrink factor - yshrink → :yshrink (float): Vertical shrink factor - vshrink → :vshrink (float): Vertical shrink factor

Optional inputs: - kernel → :kernel (keyword, see ol.vips.enums/kernel): Resampling kernel - gap → :gap (float): Reducing gap - centre → :centre (boolean): Use centre sampling convention

Outputs: - out → :out (image): Output image

shrink an image horizontally

Operation name: reduceh.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - xshrink → :xshrink (float): Horizontal shrink factor - hshrink → :hshrink (float): Horizontal shrink factor

Optional inputs: - kernel → :kernel (keyword, see ol.vips.enums/kernel): Resampling kernel - gap → :gap (float): Reducing gap - centre → :centre (boolean): Use centre sampling convention

Outputs: - out → :out (image): Output image

shrink an image vertically

Operation name: reducev.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - yshrink → :yshrink (float): Vertical shrink factor - vshrink → :vshrink (float): Vertical shrink factor

Optional inputs: - kernel → :kernel (keyword, see ol.vips.enums/kernel): Resampling kernel - gap → :gap (float): Reducing gap - centre → :centre (boolean): Use centre sampling convention

Outputs: - out → :out (image): Output image

relational operation on two images

Operation name: relational.

Returns an image handle.

Required inputs: - left → :left (image): Left-hand image argument - right → :right (image): Right-hand image argument - relational → :relational (keyword, see ol.vips.enums/operation-relational): Relational to perform

Optional inputs: - none

Outputs: - out → :out (image): Output image

relational operations against a constant

Operation name: relational_const.

Returns an image handle.

Required inputs: - input → :in (image): Input image - relational → :relational (keyword, see ol.vips.enums/operation-relational): Relational to perform - c → :c (seqable of number): Array of constants

Optional inputs: - none

Outputs: - out → :out (image): Output image

remainder after integer division of two images

Operation name: remainder.

Returns an image handle.

Required inputs: - left → :left (image): Left-hand image argument - right → :right (image): Right-hand image argument

Optional inputs: - none

Outputs: - out → :out (image): Output image

remainder after integer division of an image and a constant

Operation name: remainder_const.

Returns an image handle.

Required inputs: - input → :in (image): Input image - c → :c (seqable of number): Array of constants

Optional inputs: - none

Outputs: - out → :out (image): Output image

rebuild an mosaiced image

Operation name: remosaic.

Returns an image handle.

Required inputs: - input → :in (image): Input image - old-str → :old-str (string): Search for this string - new-str → :new-str (string): And swap for this string

Optional inputs: - none

Outputs: - out → :out (image): Output image

replicate an image

Operation name: replicate.

Returns an image handle.

Required inputs: - input → :in (image): Input image - across → :across (integer): Repeat this many times horizontally - down → :down (integer): Repeat this many times vertically

Optional inputs: - none

Outputs: - out → :out (image): Output image

resize an image

Operation name: resize.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - scale → :scale (float): Scale image by this factor

Optional inputs: - kernel → :kernel (keyword, see ol.vips.enums/kernel): Resampling kernel - gap → :gap (float): Reducing gap - centre → :centre (boolean): Use centre sampling convention - vscale → :vscale (float): Vertical scale image by this factor - idx → :idx (float): Horizontal input displacement - idy → :idy (float): Vertical input displacement

Outputs: - out → :out (image): Output image

rotate an image

Operation name: rot.

Returns an image handle.

Required inputs: - input → :in (image): Input image - angle → :angle (keyword, see ol.vips.enums/angle): Angle to rotate image

Optional inputs: - none

Outputs: - out → :out (image): Output image

rotate an image

Operation name: rot45.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - angle → :angle (keyword, see ol.vips.enums/angle45): Angle to rotate image

Outputs: - out → :out (image): Output image

rotate an image by a number of degrees

Operation name: rotate.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - angle → :angle (float): Rotate clockwise by this many degrees

Optional inputs: - background → :background (seqable of number): Background value - odx → :odx (float): Horizontal output displacement - ody → :ody (float): Vertical output displacement - idx → :idx (float): Horizontal input displacement - idy → :idy (float): Vertical input displacement

Outputs: - out → :out (image): Output image

perform a round function on an image

Operation name: round.

Returns an image handle.

Required inputs: - input → :in (image): Input image - round → :round (keyword, see ol.vips.enums/operation-round): Rounding operation to perform

Optional inputs: - none

Outputs: - out → :out (image): Output image

transform sRGB to HSV

Operation name: sRGB2HSV.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

convert an sRGB image to scRGB

Operation name: sRGB2scRGB.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

convert scRGB to BW

Operation name: scRGB2BW.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - depth → :depth (integer): Output device space depth in bits

Outputs: - out → :out (image): Output image

transform scRGB to XYZ

Operation name: scRGB2XYZ.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

convert scRGB to sRGB

Operation name: scRGB2sRGB.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - depth → :depth (integer): Output device space depth in bits

Outputs: - out → :out (image): Output image

scale an image to uchar

Operation name: scale.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - exp → :exp (float): Exponent for log scale - log → :log (boolean): Log scale

Outputs: - out → :out (image): Output image

Scharr edge detector

Operation name: scharr.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

create an SDF image

Operation name: sdf.

Returns an image handle.

Required inputs: - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels - shape → :shape (keyword, see ol.vips.enums/sdf-shape): SDF shape to create

Optional inputs: - r → :r (float): Radius - a → :a (seqable of number): Point a - b → :b (seqable of number): Point b - corners → :corners (seqable of number): Corner radii

Outputs: - out → :out (image): Output image

check sequential access

Operation name: sequential.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - trace → :trace (boolean): Trace pixel requests - tile-height → :tile-height (integer): Tile height in pixels - access → :access (keyword, see ol.vips.enums/access): Expected access pattern

Outputs: - out → :out (image): Output image

unsharp masking for print

Operation name: sharpen.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - radius → :radius (integer): Radius of Gaussian - sigma → :sigma (float): Sigma of Gaussian - x1 → :x1 (float): Flat/jaggy threshold - y2 → :y2 (float): Maximum brightening - y3 → :y3 (float): Maximum darkening - m1 → :m1 (float): Slope for flat areas - m2 → :m2 (float): Slope for jaggy areas

Outputs: - out → :out (image): Output image

shrink an image

Operation name: shrink.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - xshrink → :xshrink (float): Horizontal shrink factor - hshrink → :hshrink (float): Horizontal shrink factor - yshrink → :yshrink (float): Vertical shrink factor - vshrink → :vshrink (float): Vertical shrink factor

Optional inputs: - ceil → :ceil (boolean): Round-up output dimensions

Outputs: - out → :out (image): Output image

shrink an image horizontally

Operation name: shrinkh.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - xshrink → :xshrink (integer): Horizontal shrink factor - hshrink → :hshrink (integer): Horizontal shrink factor

Optional inputs: - ceil → :ceil (boolean): Round-up output dimensions

Outputs: - out → :out (image): Output image

shrink an image vertically

Operation name: shrinkv.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - yshrink → :yshrink (integer): Vertical shrink factor - vshrink → :vshrink (integer): Vertical shrink factor

Optional inputs: - ceil → :ceil (boolean): Round-up output dimensions

Outputs: - out → :out (image): Output image

unit vector of pixel

Operation name: sign.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

similarity transform of an image

Operation name: similarity.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument

Optional inputs: - scale → :scale (float): Scale by this factor - angle → :angle (float): Rotate clockwise by this many degrees - background → :background (seqable of number): Background value - odx → :odx (float): Horizontal output displacement - ody → :ody (float): Vertical output displacement - idx → :idx (float): Horizontal input displacement - idy → :idy (float): Vertical input displacement

Outputs: - out → :out (image): Output image

make a 2D sine wave

Operation name: sines.

Returns an image handle.

Required inputs: - width → :width (integer): Image width in pixels - height → :height (integer): Image height in pixels

Optional inputs: - uchar → :uchar (boolean): Output an unsigned char image - hfreq → :hfreq (float): Horizontal spatial frequency - vfreq → :vfreq (float): Vertical spatial frequency

Outputs: - out → :out (image): Output image

extract an area from an image

Operation name: smartcrop.

Returns a closeable result map. Pass it anywhere an image is expected, or inspect :out and the additional outputs directly.

Required inputs: - input → :input (image): Input image - width → :width (integer): Width of extract area - height → :height (integer): Height of extract area

Optional inputs: - interesting → :interesting (keyword, see ol.vips.enums/interesting): How to measure interestingness - premultiplied → :premultiplied (boolean): Input image already has premultiplied alpha

Outputs: - out → :out (image): Output image - attention-x → :attention-x (integer): Horizontal position of attention centre - attention-y → :attention-y (integer): Vertical position of attention centre

Sobel edge detector

Operation name: sobel.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

spatial correlation

Operation name: spcor.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - ref → :ref (image): Input reference image

Optional inputs: - none

Outputs: - out → :out (image): Output image

make displayable power spectrum

Operation name: spectrum.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output image

find many image stats

Operation name: stats.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - none

Outputs: - out → :out (image): Output array of statistics

statistical difference

Operation name: stdif.

Returns an image handle.

Required inputs: - input → :in (image): Input image - width → :width (integer): Window width in pixels - height → :height (integer): Window height in pixels

Optional inputs: - s0 → :s0 (float): New deviation - b → :b (float): Weight of new deviation - m0 → :m0 (float): New mean - a → :a (float): Weight of new mean

Outputs: - out → :out (image): Output image

subsample an image

Operation name: subsample.

Returns an image handle.

Required inputs: - input → :input (image): Input image - xfac → :xfac (integer): Horizontal subsample factor - yfac → :yfac (integer): Vertical subsample factor

Optional inputs: - point → :point (boolean): Point sample

Outputs: - out → :out (image): Output image

subtract two images

Operation name: subtract.

Returns an image handle.

Required inputs: - left → :left (image): Left-hand image argument - right → :right (image): Right-hand image argument

Optional inputs: - none

Outputs: - out → :out (image): Output image

sum an array of images

Operation name: sum.

Returns an image handle.

Required inputs: - input → :in (seqable of image): Array of input images

Optional inputs: - none

Outputs: - out → :out (image): Output image

load SVG with rsvg

Operation name: svgload.

Returns a closeable result map. Pass it anywhere an image is expected, or inspect :out and the additional outputs directly.

Required inputs: - filename → :filename (string): Filename to load from

Optional inputs: - dpi → :dpi (float): Render at this DPI - scale → :scale (float): Scale output by this factor - unlimited → :unlimited (boolean): Allow SVG of any size - stylesheet → :stylesheet (string): Custom CSS - high-bitdepth → :high-bitdepth (boolean): Enable scRGB 128-bit output (32-bit per channel) - memory → :memory (boolean): Force open via memory - access → :access (keyword, see ol.vips.enums/access): Required access pattern for this file - fail-on → :fail-on (keyword, see ol.vips.enums/fail-on): Error level to fail on - revalidate → :revalidate (boolean): Don’t use a cached result for this operation - sequential → :sequential (boolean): Sequential read only - fail → :fail (boolean): Fail on first warning - disc → :disc (boolean): Open to disc

Outputs: - out → :out (image): Output image - flags → :flags (integer flags): Flags for this file

find the index of the first non-zero pixel in tests

Operation name: switch.

Returns an image handle.

Required inputs: - tests → :tests (seqable of image): Table of images to test

Optional inputs: - none

Outputs: - out → :out (image): Output image

run an external command

Operation name: system.

Returns a closeable result map. Pass it anywhere an image is expected, or inspect :out and the additional outputs directly.

Required inputs: - cmd-format → :cmd-format (string): Command to run

Optional inputs: - input → :in (seqable of image): Array of input images - out-format → :out-format (string): Format for output filename - in-format → :in-format (string): Format for input filename

Outputs: - out → :out (image): Output image - log → :log (string): Command log

make a text image

Operation name: text.

Returns a closeable result map. Pass it anywhere an image is expected, or inspect :out and the additional outputs directly.

Required inputs: - text → :text (string): Text to render

Optional inputs: - font → :font (string): Font to render with - width → :width (integer): Maximum image width in pixels - height → :height (integer): Maximum image height in pixels - align → :align (keyword, see ol.vips.enums/align): Align on the low, centre or high edge - justify → :justify (boolean): Justify lines - dpi → :dpi (integer): DPI to render at - spacing → :spacing (integer): Line spacing - fontfile → :fontfile (string): Load this font file - rgba → :rgba (boolean): Enable RGBA output - wrap → :wrap (keyword, see ol.vips.enums/text-wrap): Wrap lines on word or character boundaries

Outputs: - out → :out (image): Output image - autofit-dpi → :autofit-dpi (integer): DPI selected by autofit

generate thumbnail from file

Operation name: thumbnail.

Returns an image handle.

Required inputs: - filename → :filename (string): Filename to read from - width → :width (integer): Size to this width

Optional inputs: - height → :height (integer): Size to this height - size → :size (keyword, see ol.vips.enums/size): Only upsize, only downsize, or both - no-rotate → :no-rotate (boolean): Don’t use orientation tags to rotate image upright - crop → :crop (keyword, see ol.vips.enums/interesting): Reduce to fill target rectangle, then crop - linear → :linear (boolean): Reduce in linear light - input-profile → :input-profile (string): Fallback input profile - output-profile → :output-profile (string): Fallback output profile - intent → :intent (keyword, see ol.vips.enums/intent): Rendering intent - fail-on → :fail-on (keyword, see ol.vips.enums/fail-on): Error level to fail on - auto-rotate → :auto-rotate (boolean): Use orientation tags to rotate image upright - import-profile → :import-profile (string): Fallback import profile - export-profile → :export-profile (string): Fallback export profile

Outputs: - out → :out (image): Output image

generate thumbnail from image

Operation name: thumbnail_image.

Avoid for routine thumbnailing. Prefer thumbnail when you can start from a filename.For already-loaded images, use normal image operations such as resize unless you specifically need this escape hatch.

Returns an image handle.

Required inputs: - input → :in (image): Input image argument - width → :width (integer): Size to this width

Optional inputs: - height → :height (integer): Size to this height - size → :size (keyword, see ol.vips.enums/size): Only upsize, only downsize, or both - no-rotate → :no-rotate (boolean): Don’t use orientation tags to rotate image upright - crop → :crop (keyword, see ol.vips.enums/interesting): Reduce to fill target rectangle, then crop - linear → :linear (boolean): Reduce in linear light - input-profile → :input-profile (string): Fallback input profile - output-profile → :output-profile (string): Fallback output profile - intent → :intent (keyword, see ol.vips.enums/intent): Rendering intent - fail-on → :fail-on (keyword, see ol.vips.enums/fail-on): Error level to fail on - auto-rotate → :auto-rotate (boolean): Use orientation tags to rotate image upright - import-profile → :import-profile (string): Fallback import profile - export-profile → :export-profile (string): Fallback export profile

Outputs: - out → :out (image): Output image

load tiff from file

Operation name: tiffload.

Returns a closeable result map. Pass it anywhere an image is expected, or inspect :out and the additional outputs directly.

Required inputs: - filename → :filename (string): Filename to load from

Optional inputs: - page → :page (integer): First page to load - n → :n (integer): Number of pages to load, -1 for all - autorotate → :autorotate (boolean): Rotate image using orientation tag - subifd → :subifd (integer): Subifd index - unlimited → :unlimited (boolean): Remove all denial of service limits - memory → :memory (boolean): Force open via memory - access → :access (keyword, see ol.vips.enums/access): Required access pattern for this file - fail-on → :fail-on (keyword, see ol.vips.enums/fail-on): Error level to fail on - revalidate → :revalidate (boolean): Don’t use a cached result for this operation - sequential → :sequential (boolean): Sequential read only - fail → :fail (boolean): Fail on first warning - disc → :disc (boolean): Open to disc

Outputs: - out → :out (image): Output image - flags → :flags (integer flags): Flags for this file

save image to tiff file

Operation name: tiffsave.

Returns a result map.

Required inputs: - input → :in (image): Image to save - filename → :filename (string): Filename to save to

Optional inputs: - compression → :compression (keyword, see ol.vips.enums/foreign-tiff-compression): Compression for this file - q → :Q (integer): Q factor - predictor → :predictor (keyword, see ol.vips.enums/foreign-tiff-predictor): Compression prediction - tile → :tile (boolean): Write a tiled tiff - tile-width → :tile-width (integer): Tile width in pixels - tile-height → :tile-height (integer): Tile height in pixels - pyramid → :pyramid (boolean): Write a pyramidal tiff - miniswhite → :miniswhite (boolean): Use 0 for white in 1-bit images - bitdepth → :bitdepth (integer): Write as a 1, 2, 4 or 8 bit image - resunit → :resunit (keyword, see ol.vips.enums/foreign-tiff-resunit): Resolution unit - xres → :xres (float): Horizontal resolution in pixels/mm - yres → :yres (float): Vertical resolution in pixels/mm - bigtiff → :bigtiff (boolean): Write a bigtiff image - properties → :properties (boolean): Write a properties document to IMAGEDESCRIPTION - region-shrink → :region-shrink (keyword, see ol.vips.enums/region-shrink): Method to shrink regions - level → :level (integer): Deflate (1-9, default 6) or ZSTD (1-22, default 9) compression level - lossless → :lossless (boolean): Enable WEBP lossless mode - depth → :depth (keyword, see ol.vips.enums/foreign-dz-depth): Pyramid depth - subifd → :subifd (boolean): Save pyr layers as sub-IFDs - premultiply → :premultiply (boolean): Save with premultiplied alpha - rgbjpeg → :rgbjpeg (boolean): Output RGB JPEG rather than YCbCr - squash → :squash (boolean): Squash images down to 1 bit - keep → :keep (integer flags): Which metadata to retain - background → :background (seqable of number): Background value - page-height → :page-height (integer): Set page height for multipage save - profile → :profile (string): Filename of ICC profile to embed - strip → :strip (boolean): Strip all metadata from image

Outputs: - none

cache an image as a set of tiles

Operation name: tilecache.

Returns an image handle.

Required inputs: - input → :in (image): Input image

Optional inputs: - tile-width → :tile-width (integer): Tile width in pixels - tile-height → :tile-height (integer): Tile height in pixels - max-tiles → :max-tiles (integer): Maximum number of tiles to cache - access → :access (keyword, see ol.vips.enums/access): Expected access pattern - threaded → :threaded (boolean): Allow threaded access - persistent → :persistent (boolean): Keep cache between evaluations

Outputs: - out → :out (image): Output image

build a look-up table

Operation name: tonelut.

Returns an image handle.

Required inputs: - none

Optional inputs: - in-max → :in-max (integer): Size of LUT to build - out-max → :out-max (integer): Maximum value in output LUT - lb → :Lb (float): Lowest value in output - lw → :Lw (float): Highest value in output - ps → :Ps (float): Position of shadow - pm → :Pm (float): Position of mid-tones - ph → :Ph (float): Position of highlights - s → :S (float): Adjust shadows by this much - m → :M (float): Adjust mid-tones by this much - h → :H (float): Adjust highlights by this much