Below is a list of all the available Blitline functions.

ANNOTATE

Adds text to an image

Sample:

{
    "name":"annotate",
    "params":{
        "text":"my_text",
        "color":"#ffffff"
    }
}

Required:

• text : Text to be placed on image

Optional:

• x : X offset (defaults to 0)
• y : Y offset (defaults to 0)
• color : Color of text (defaults to ‘#ffffff’)
• style : “normal” or “italic” or “oblique” (defaults to “normal”)
• kerning : Distance between letters (defaults based on font)
• font_weight : “bold” or “normal” (defaults to “bold”)
• font : Font of text (defaults to ‘Arial’) 
  Need an Open Source font added? Write us at support@blitline.com
• point_size : Size of text (defaults to 32)
• stretch : Stretch value (Normal/Expanded/Condensed)
• stroke : Color of stroke (defaults to “transparent”)
• dropshadow _color : Adds a dropshadow of a specified color
• dropshadow _offset : Pixels down/right for dropshadow, if dropshadow_color is set. 
  (defaults to 3)
• gravity : Placement of text (defaults to ‘CenterGravity’)

Example: http://www.blitline.com/docs/gist_runner?gist_id=5437247

APPEND

Appends images together either vertically or horizontally

Sample:

{
              "name":"append",
              "params":{
                  "vertical":false
              }
          }

Optional:

• vertical : Whether images are appended vertically(true) or horizontally(false)
• other_images : Comma separated list of urls to other images

Example: http://www.blitline.com/docs/gist_runner?gist_id=5437148

AUTO LEVEL

Automatically adjusts the levels the color channels of an image

Sample:

{
              "name":"auto_level"
          }

AUTO GAMMA

Automatically adjusts the brightness levels of the channels of an image

Sample:

{
              "name":"auto_gamma"
          }

AUTO ENHANCE

Automatically ‘enhances’ (magic wand) an image.

Sample:

{
              "name":"auto_enhance"
          }

BLUR

Blurs an image

Sample:

{
              "name":"blur"
          }

Optional:

• sigma : Gaussian sigma of blur (defaults to 1.0)
• radius : Gaussian radius of blur (defaults to 0.0)}

BACKGROUND COLOR

Sets a transparent background color to be a solid (useful when converting pngs to jpgs)

Sample:

{
              "name":"background_color",
              "params":{}
          }

Optional:

• color : Color you want for the background color (defaults to ‘#ffffff’)

COMPOSITE

Composites one image onto another

Sample:

{
              "name":"composite",
              "params":{}
          }

Required:

• src : Url of image you wants composited with original image

Optional:

• scale_to_fit : { “width” : width, “height” : height }, to automatically scale src specific size. Can also be percentage if prefixed with %
• scale_to_match : “true” or “false” to automatically scale src to the same size as current image (defaults to false)
• scale_to_fill : { “width” : width, “height” : height }, to automatically scale src to fill specific size. Can also be percentage if prefixed with %
• as_mask : “true” or “false” to use src as a greyscale mask (defaults to false)
• x : X offset of where to place image on original image
• y : Y offset of where to place image on original image
• gravity : Instead of x,y you could use gravity.
• composite_op : How composite is to be applied. Defaults to “OverCompositeOp” (which means it will just be layed on top of original image). See “Composite Ops” section below for more options

Example: http://www.blitline.com/docs/gist_runner?gist_id=5095014

CONTRAST

Adjusts contrasts within the image.

Sample:

{
              "name":"contrast",
              "params":{}
          }

Optional:

• sharpen : Contrast is increased if true (defaults to false)

CAPTION

Annotates an image with text autowrap feature.

Sample:

{
              "name":"caption",
              "params":{ "text" : "Sample Text" }
          }

Required:

• text : Text to be placed on image

Optional:

• x : X offset (defaults to 0)
• y : Y offset (defaults to 0)
• width : Width of text area, either in pixels or percentage (ie. ‘90%’)
• height : Height of text area, either in pixels or percentage (ie. ‘90%’)
• color : Color of text (defaults to ‘#ffffff’)
• font_weight : “bold” or “normal” (defaults to “bold”)
• font : Font of text (defaults to ‘Arial’) 
  Need an Open Source font added? Write us at support@blitline.com
• text_gravity : Where to align text, defaults to CenterGravity
• point_size : Size of text
• gravity : Placement of text (defaults to ‘CenterGravity’)

Example: http://www.blitline.com/docs/gist_runner?gist_id=8f12eeee40e5bb5ec299

CONTRAST STRETCH CHANNEL

Adjusts contrasts within the image.

Sample:

{
              "name":"contrast_stretch_channel",
              "params":{
                  "black_point":10
              }
          }

Required:

• black_point : Burn at most this many pixels. Specify an absolute number of pixels as a numeric value

Optional:

• white_point : Burn at most this many pixels. Specify an absolute number of pixels as a numeric value. If not given defaults to all_points-black_point

CONVERT COMMAND

Advanced function with direct access to IM’s convert command.

Sample:

{
              "name":"convert_command",
              "params":{}
          }

Optional:

• **** : Each param is an option. If the option has a value, set the value, otherwise leave as empty string.

Example: http://blog.blitline.com/post/40641947670/convert-command

CROP

Crop an image to a specific size. 

Note: This is not used very often. You are probably looking for “resize_to_fill”.

Sample:

{
              "name":"crop",
              "params":{
                  "x":0,
                  "y":0,
                  "width":10,
                  "height":10
              }
          }

Required:

• width : Width of resulting image

Optional:

• height : Height of resulting image
• x : X offset
• y : Y offset
• preserve_aspect_if_smaller : If source image is smaller than target size, crop smaller image to still be same aspect ratio (default false)
• gravity : Sets the starting gravity of where the x,y will offset from

Example: http://www.blitline.com/docs/gist_runner?gist_id=5109149

CROP TO SQUARE

Crop an image to a sqaure, based on height vs width. Square side length will be the smaller of the 2.

Sample:

{
              "name":"crop_to_square",
              "params":{}
          }

Optional:

• gravity : Gravity of resulting crop (default CenterGravity)

Example: http://www.blitline.com/docs/gist_runner?gist_id=5294156

DELETE PROFILE

Deletes color profile information.

Sample:

{
              "name":"delete_profile",
              "params":{}
          }

Required:

• name : Name of the profile to remove (or * to remove wildcard)

DESKEW

Tries to relalign a slightly distorted image. (Typically used in scanning and OCR)

Sample:

{
              "name":"deskew",
              "params":{}
          }

Optional:

• threshold : Maximum threshold percentage for deskewing (Default = 0.40)

DENSITY

Sets the DPI of an image

Sample:

{
              "name":"density",
              "params":{
                  "dpi":"200"
              }
          }

Required:

• dpi : Sets the DPI of the image

DESPECKLE

Reduces the speckle noise while preserving the edges

Sample:

{
              "name":"despeckle",
              "params":{}
          }

DISSOLVE

Composites with transparency

Sample:

{
              "name":"dissolve",
              "params":{}
          }

Required:

• src : Url of image you wants composited on top of original image

Optional:

• scale_to_fit : { “width” : width, “height” : height }, to automatically scale src to fit within specific size. Can also be percentage if suffixed with >#/li###
• scale_to_fill : { “width” : width, “height” : height }, to automatically scale src to fill the area defined. Can also be percentage if suffixed with >#/li###
• scale_to_match : “true” or “false” to automatically scale src to the same size as current image (defaults to false)
• as_mask : “true” or “false” to use src as a greyscale mask (defaults to false)
• x : X offset of where to place image on original image
• y : Y offset of where to place image on original image
• gravity : Instead of x,y you could use gravity.
• src_percentage : Percentage (0.0-1.0) of alpha on overlayed image (default 0.25)
• dst_percentage : Percentage (0.0-1.0) of alpha on original (bottom) image (default 1.0)

Example: http://www.blitline.com/docs/gist_runner?gist_id=5095014

ELLIPSE

Draws an ellipse

Sample:

{
              "name":"ellipse",
              "params":{
                  "origin_x":100,
                  "origin_y":100,
                  "ellipse_width":50,
                  "ellipse_height":30,
                  "stroke_width":5,
                  "color":"#ffffff",
               }
          }

Required:

• origin_x : Center X coordinate
• origin_y : Center Y coordinate
• ellipse_width : Width of ellipse
• ellipse_height : Height of ellipse

Optional:

• color : Color of stroke (default “#ffffff”)
• stroke_width : Width of ellipse perimeter(stroke) line (default 0, no stroke)
• stroke_opacity : Opacity of stroke (default 1.0)
• fill_color : Color to fill the ellipse with (defaults to ‘color’ value)
• fill_opacity : Opacity of fill (defaults to 1.0)

Example: http://www.blitline.com/docs/gist_runner?gist_id=8200526

ENHANCE

Reduces noise in the image

Sample:

{
              "name":"enhance",
              "params":{}
          }

EQUALIZE

Equalizes an image (Auto-adjust image).

Sample:

{
              "name":"equalize",
              "params":{}
          }

GAMMA CHANNEL

Adjusts contrasts within the image.

Sample:

{
              "name":"gamma_channel",
              "params":{
                  "gamma":1.0
              }
          }

Required:

• gamma : Gamma adjustent (Usually 0.8 to 2.3)

GRAY COLORSPACE

Turns image into grayscale.

Sample:

{
              "name":"gray_colorspace",
              "params":{}
          }

IMAGE GRID

Builds a grid of input images

Sample:

{
          "name":"image_grid",
          "params":{
              "images": [
                "https://s3.amazonaws.com/img.blitline/skysmall.jpg",
                "https://unsplash.it/200/300/?random",
                "https://unsplash.it/200/300/?random",
                "https://unsplash.it/200/300/?random",
                "https://unsplash.it/200/300/?random",
                "https://unsplash.it/200/300/?random"
              ],
              "cell_width": 200,
              "cell_height" : 200,
              "columns" : 3,
              "padding" : 2,
              "color" : "#ffda5a"
          }

Required:

• images : Array of images to be placed into the grid
• cell_width : Width of cell to output
• cell_height : Height of cell to output
• columns : Number of columns to display

Optional:

• padding : Padding between cells
• color : Color of padding

Example: https://www.blitline.com/v3/home/gist?gist_id=af4943b5e1297b5214494d2ed600e7a5

IMAGGA SMART CROP

Uses Imagga image analysis tools to determine the best crop for you photo. This requires a Blitline+Imagga subscription.

Sample:

{
            "name":"imagga_smart_crop",
            "params":{
              "resolution" : "150x150"
             }
          }

Required:

• resolution : The height and width of the desired cropped image. (Height and width are separated by a lower case ‘x’)

Optional:

• no_scaling : Optional setting to not autoscale image, but to crop the raw original to the target area. Defaults to false

Example: http://www.blitline.com/docs/gist_runner?gist_id=58d9007c1a7c304c254b

LINE

Draws a linear line between two points.

Sample:

{
              "name":"line",
              "params":{
                  "x":10,
                  "y":10,
                  "x1":50,
                  "y1":50,
                  "width":1,
                  "color":"#ffffff",
                  "opacity":1.0,
                  "line_cap":"butt"
              }
          }

Required:

• x : Starting X coordinate
• y : Starting Y coordinate
• x1 : Ending X coordinate
• y1 : Ending Y coordinate

Optional:

• width : Width of line (default 1)
• color : Color of line (default “#ffffff”)
• opacity : Opacity of line (default 1.0)
• line_cap : How the line ends. Only relevant for widths > 1. Two possible options are “butt”(default) and “round”(rounds ends).

LEVEL

Levels channels of image

Sample:

{
              "name":"level",
              "params":{
            }
          }

Required:

Optional:

• channel : Channel to operate on (defualt AllChannels)
• black_point : Starting black point (default 0.0)
• white_point : Ending white point (default 65535.0)
• gamma : Gamma offset

LEVELIZE

Inverse of ‘level’

Sample:

{
              "name":"level",
              "params":{
            }
          }

Required:

Optional:

• channel : Channel to operate on (defualt AllChannels)
• black_point : Starting black point (default 0.0)
• white_point : Ending white point (default 65535.0)
• gamma : Gamma offset

LIQUID RESCALE

Uses seam carving to reduce image size

Sample:

{
              "name":"liquid_rescale",
              "params":{
                  "width":10,
                  "height":10
              }
          }

Required:

• width : Target width
• height : Target height

Optional:

• delta_x : Maximum seam transversal step (default 0)
• rigidity : Bias for non-straight seams (default 0)

Example: http://www.blitline.com/docs/gist_runner?gist_id=5778e028450aece00814

MEDIAN FILTER

Applies a digital filter that improves the quality of a noisy image. Each pixel is replaced by the median in a set of neighboring pixels as defined by radius.

Sample:

{
              "name":"median_filter",
              "params":{}
          }

Optional:

• radius : Radius of blur (defaults to 1.0)

MODULATE

Changes the brightness, saturation, and hue.

Sample:

{
              "name":"modulate",
              "params":{}
          }

Optional:

• Brightness : Brightness adjustment (defaults to 1.0)
• Saturation : Brightness adjustment(defaults to 1.0)
• Hue : Hue adjustment (defaults to 1.0)

NO OP

Simple noop(no operation). No function performed on image. 

(If you are using this to move your original, please see ‘move original’ @ http://www.blitline.com/docs/b... instead)

Sample:

{
              "name":"no_op",
              "params":{}
          }

NORMALIZE

Changes the contrast of a color image by adjusting the pixel color to span the entire range of colors available.

Sample:

{
              "name":"normalize",
              "params":{}
          }

PAD

Add empty space to one side or all sides of image (Useful for centering an image on a new canvas color)

Sample:

{
              "name":"pad",
              "params":{
                  "size":30
              }
          }

Required:

• size : Thickness of padding

Optional:

• gravity : Location of padding (default “CenterGravity”)
• color : Color of padding (default “#ffffff”)

Example: http://www.blitline.com/docs/gist_runner?gist_id=5437331

PAD RESIZE TO FIT

Resize to fit, but will pad to keep the aspect ratio. So for example, if you are going from a 3:4 aspect ratio to a 3:2 aspect ratio, this method will assure the result the desired output size, and pad the filled in area with a specified color.

Sample:

{
              "name":"pad_resize_to_fit",
              "params":{
                  "width":"300",
                  "height":"200"
              }
          }

Required:

• width : Output width
• height : Output height

Optional:

• only_resize_larger : If set to true will only resize image if it’s larger then width or height (default false)
• color : Color for the padding (defaults to “#ffffff”)
• gravity : Location of output relative to padding (defaults to center)

Example: http://www.blitline.com/docs/gist_runner?gist_id=5437355

PHOTOGRAPH

Creates an image that has a white border, with a slight curl, that appears like a photograph

Sample:

{
              "name":"photograph",
              "params":{}
          }

Optional:

• angle : Angle of rotation

PIXELATE

Pixelates an area on an image

Sample:

{
              "name":"pixelate",
              "params":{}
          }

Optional:

• x : X position of starting area on image (default 0)
• y : Y position of starting area on image (default 0)
• width : Width of area to pixelate (defaults to width of original image)
• height : Height of area to pixelate (defaults to height of original image)
• amount : 1-100 value representing the amount to pixelate

Example: http://www.blitline.com/docs/gist_runner?gist_id=6380380

QUANTIZE

Analyzes the colors within a reference image and chooses a fixed number of colors to represent the image

Sample:

{
              "name":"quantize",
              "params":{
                  "number_colors":8
              }
          }

Required:

• number_colors : Number of colors to reduce to

Optional:

• color_space : The colorspace to quantize in (defaults to “RGBColorspace”)
• dither : Whether or not to use dithering on the resulting image (defaults to “false”)

RECTANGLE

Draws a rectangle

Sample:

{
              "name":"rectangle",
              "params":{
                  "x":10,
                  "y":10,
                  "x1":50,
                  "y1":50,
                  "stroke_width":5,
                  "color":"#ffffff",
                  "opacity":1.0,
              }
          }

Required:

• x : Starting X coordinate
• y : Starting Y coordinate
• x1 : Ending X coordinate
• y1 : Ending Y coordinate

Optional:

• color : Color of stroke (default “#ffffff”)
• stroke_width : Width of rectangle perimeter(stroke) line (default 0, no stroke)
• stroke_opacity : Opacity of stroke (default 1.0)
• fill_color : Color to fill the rectangle with (defaults to ‘color’ value)
• fill_opacity : Opacity of fill (defaults to 1.0)
• ch : corner height. If present, will cause rounded corners, and REQUIRES ‘cw’ attribute as well
• cw : corner width. If present, will cause rounded corners, and REQUIRES ‘ch’ attribute as well

Example: http://www.blitline.com/docs/gist_runner?gist_id=8200545

RESAMPLE

Resample the image to a new resolution

Sample:

{
              "name":"resample",
              "params":{
                  "density":72.0
              }
          }

Required:

• amount : The density of the outputted image. (defaults to 72.0)

RESIZE

Resize the image to a specific height and width. 

Note: This is not used very often. You are probably looking for “resize_to_fit”.

Sample:

{
              "name":"resize",
              "params":{
                  "width":10,
                  "height":10
              }
          }

Required:

• width : The new width of the image
• height : The new height of the image

Optional:

• scale_factor : Instead of height and width you can set a scale factor. (eg 0.5 = 50%)

RESIZE TO FILL

Resize the image to fit within the specified dimensions while retaining the aspect ratio of the original image. If necessary, crop the image in the larger dimension 

Common English Translation: This is probably the crop you want if you want to cut a center piece out of a photo and use it as a thumbnail. This will cut out the center (by default) to your defined size.

Sample:

{
              "name":"resize_to_fill",
              "params":{
                  "width":40,
                  "height":40
              }
          }

Required:

• width : Width of desired image
• height : Height of desired image

Optional:

• autosharpen : Automatically sharpens image after resize
• only_shrink_larger : Don’t upsize image (defaults to false)
• gravity: Force edge to align

Example: http://www.blitline.com/docs/gist_runner?gist_id=5205228

RESIZE TO FIT

Resize the image to fit within the specified dimensions while retaining the original aspect ratio. The image may be shorter or narrower than specified in the smaller dimension but will not be larger than the specified values

Common English Translation: This is probably the crop you want if you need to rescale a photo down to a smaller size while keeping the same height to width ratio.

Sample:

{
              "name":"resize_to_fit",
              "params":{
                  "width":40,
                  "height":40
              }
          }

Required:

• width : Width of desired image (optional if height defined)
• height : Height of desired image (optional if width defined)

Optional:

• only_shrink_larger : Don’t upsize image (defaults to false)
• autosharpen : Automatically sharpens image after resize
• gravity: Force edge to align

ROTATE

Rotates the image.

Sample:

{
              "name":"rotate",
              "params":{
                  "amount":25
              }
          }

Required:

• amount : The number of degrees to rotate the image.

SCALE

Resize the image to a specific height and width. 

Note: This is not used very often. You are probably looking for “resize_to_fit”.

Sample:

{
              "name":"scale",
              "params":{
                  "width":10,
                  "height":10
              }
          }

Required:

• width : The new width of the image
• height : The new height of the image

Optional:

• scale_factor : Instead of height and width you can set a scale factor. (eg 0.5 = 50%)

SCRIPT

Run your own scripts on Blitline cloud servers. Perfect for using your own ImageMagick scripts

Sample:

{
              "name":"script",
              "params":{
                  "bash_string": "convert input.png -trim output.png"}
          }

Optional:

• bash_string : String representation of a bash file that will execute on the server (requires NO ‘executable’ or ‘files)
• files : Extra files to download before the script is run (requires ‘executable’)
• executable : Command line to run script (requires ‘files’)

Example: http://www.blitline.com/docs/scripts

SEPIA TONE

Applies sepia filter

Sample:

{
              "name":"sepia_tone",
              "params":{}
          }

Optional:

• threshold : Threshold for quantizing sepia tone

SHARPEN

Sharpens the image

Sample:

{
              "name":"sharpen",
              "params":{}
          }

Optional:

• sigma : Gaussian sigma of sharpen (defaults to 1.0)
• radius : Gaussian radius of shapen (defaults to 0.0)

SKETCH

Simulates a pencil sketch.

Sample:

{
              "name":"sketch",
              "params":{}
          }

Optional:

• sigma : Gaussian operator (defaults to 0.0)
• radius : Gaussian operator (defaults to 0.0)
• angle : Angle of sketch (defaults to 0.0)}

STEGANO

Embeds a hidden watermark in the image. 

NOTE: Watermark image must be a greyscale image, AND image saved to your destination MUST be PNG. Jpeg compression obscures IM stegano signature.

Sample:

{
              "name":"stegano",
              "params":{ "watermark_url" : "http://www.mysite.com/watermark.png"}
          }

Required:

• watermark_url : Url of watermark to embed in image (must be grayscale)

Optional:

• offset : Pixel offset from beginning of image to embed hidden watermark (defaults to 0.0)

TILE

Tiles a src image over the current image.

Sample:

{
              "name":"tile",
              "params":{ "src":"http://https://s3.amazonaws.com/img.blitline/test_pngs/apple.png" }
          }

Required:

• src : Smaller image to be tiled on top of image

Optional:

• scale : Scale factor for ‘src’ image (in the event it needs to be scaled) (defaults to 1.0)
• width : Resize ‘src’ to width, requires height as well(if set, scale is ignored)
• height : Resize ‘src’ to height, requires width as well(if set, scale is ignored)

TRIM

Makes a ‘best guess’ crop to upper-left and lower-right corners. For example, if you have an image with a bunch of white border around it, and you want it cropped to only where there something other than the border color.

Sample:

{
              "name":"trim",
              "params":{}
          }

Optional:

• fuzz : Fuzz the trimming edge. For JPEGs, due to compression or anti-aliasing often times edges aren’t a clean line. The “fuzz” values allows you to trim with a slight extra fuzz around the trim area. (Defaults to 0.0, valid values are 0.0 - 1.0)

UNSHARP MASK

Sharpens an image

Sample:

{
              "name":"unsharp_mask",
              "params":{}
          }

Optional:

• sigma : Gaussian operator (defaults to 1.0)
• radius : Gaussian operator (defaults to 0.0)
• amount : The percentage of the blurred image to be added to the receiver, specified as a fraction between 0 and 1.0 (defaults to 1.0)
• threshold : The threshold needed to apply the amount, specified as a fraction between 0 and 1.0 (defaults to 0.05)}

VIGNETTE

Gradually shades the edges of the image by transforming the pixels into the background color.

Sample:

{
              "name":"vignette",
              "params":{}
          }

Optional:

• color : Background color to fade to (default is ‘#000000’)
• x : Influences the amount of background color in the horizontal dimension. (default = 10)
• y : Influences the amount of background color in the vertical dimension. (default = 10)
• threshold : The threshold needed to apply the amount, specified as a fraction between 0 and 1.0 (defaults to 0.05)
• sigma : Gaussian operator (defaults to 10.0)
• radius : Gaussian operator (defaults to 0.0)

WATERMARK

Adds a text watermark to an image. For more control use ‘annotate’

Sample:

{
              "name":"watermark",
              "params":{
                  "text":"Image processing by Blitline"
              }
          }

Required:

• text : Text to add to image

Optional:

• gravity : Relative positioning of text (default is ‘CenterGravity’)
• point_size : Point size of text. (default = 94)
• font_family : Font family of text. (default = ‘Helvetica’)
• opacity : The opacity of the text on the image (defaults to 0.45)

Example: http://www.blitline.com/docs/gist_runner?gist_id=5437386

Appendix:

Compose Operations

UndefinedCompositeOp

No composite operator has been specified.

AddCompositeOp

The result of composite image + image, with overflow wrapping around (mod 256).

AtopCompositeOp

The result is the same shape as image, with composite image obscuring image where the image shapes overlap. Note that this differs from OverCompositeOp because the portion of composite image outside of image's shape does not appear in the result.

BlurCompositeOp

BumpmapCompositeOp

The result image shaded by composite image.

ChangeMaskCompositeOp

Replace any destination pixel that is the similar to the source image's pixel (as defined by the current fuzz factor), with transparency.

ClearCompositeOp

Make the target image transparent. The composite image is ignored.

ColorBurnCompositeOp

Darkens the destination color to reflect the source color. Painting with white produces no change.

ColorDodgeCompositeOp

Brightens the destination color to reflect the source color. Painting with black produces no change.

ColorizeCompositeOp

Each pixel in the result image is the combination of the brightness of the target image and the saturation and hue of the composite image. This is the opposite of LuminizeCompositeOp.

CopyCompositeOp

Replace the target image with the composite image.

CopyBlackCompositeOp

Copy the black channel from the composite image to the target image.

CopyBlueCompositeOp

Copy the blue channel from the composite image to the target image.

CopyCyanCompositeOp

Copy the cyan channel from the composite image to the target image.

CopyGreenCompositeOp

Copy the green channel from the composite image to the target image.

CopyMagentaCompositeOp

Copy the magenta channel from the composite image to the target image.

CopyOpacityCompositeOp

If the composite image's matte attribute is true, copy the opacity channel from the composite image to the target image. Otherwise, set the target image pixel's opacity to the intensity of the corresponding pixel in the composite image.

CopyRedCompositeOp

Copy the red channel from the composite image to the target image.

CopyYellowCompositeOp

Copy the yellow channel from the composite image to the target image.

DarkenCompositeOp

Replace target image pixels with darker pixels from the composite image.

DifferenceCompositeOp

The result of abs(composite image - image). This is useful for comparing two very similar images.

DisplaceCompositeOp

Displace target image pixels as defined by a displacement map. The operator used by the displace method.

DissolveCompositeOp

The operator used in the dissolve method.

DstCompositeOp

The destination is left untouched.

DstAtopCompositeOp

The part of the destination lying inside of the source is composited over the source and replaces the destination.

DstInCompositeOp

The part of the destination lying inside of the source replaces the destination.

DstOutCompositeOp

The part of the destination lying outside of the source replaces the destination.

DstOverCompositeOp

The destination is composited over the source and the result replaces the destination.

ExclusionCompositeOp

Produces an effect similar to that of 'difference', but appears as lower contrast. Painting with white inverts the destination color. Painting with black produces no change.

HardLightCompositeOp

Multiplies or screens the colors, dependent on the source color value. If the source color is lighter than 0.5, the destination is lightened as if it were screened. If the source color is darker than 0.5, the destination is darkened, as if it were multiplied. The degree of lightening or darkening is proportional to the difference between the source color and 0.5. If it is equal to 0.5 the destination is unchanged. Painting with pure black or white produces black or white.

HueCompositeOp

Each pixel in the result image is the combination of the hue of the target image and the saturation and brightness of the composite image.

InCompositeOp

The result is simply composite image cut by the shape of image. None of the image data of image is included in the result.

LightenCompositeOp

Replace target image pixels with lighter pixels from the composite image.

LinearBurnCompositeOp

Same as LinearDodgeCompositeOp, but also subtract one from the result. Sort of a additive 'Screen' of the images.

LinearDodgeCompositeOp

This is equivelent to PlusCompositeOp in that the color channels are simply added, however it does not "plus" the alpha channel, but uses the normal OverCompositeOp alpha blending, which transparencies are involved. Produces a sort of additive multiply-like result.

LinearLightCompositeOp

Increase contrast slightly with an impact on the foreground's tonal values.

LuminizeCompositeOp

Each pixel in the result image is the combination of the brightness of the composite image and the saturation and hue of the target image. This is the opposite of ColorizeCompositeOp.

MinusCompositeOp

The result of composite image - image, with overflow cropped to zero. The matte chanel is ignored (set to 255, full coverage).

ModulateCompositeOp

Used by the watermark method.

MultiplyCompositeOp

Multiplies the color of each target image pixel by the color of the corresponding composite image pixel. The result color is always darker.

NoCompositeOp

No composite operator has been specified.

OutCompositeOp

The resulting image is composite image with the shape of image cut out.

OverCompositeOp

The result is the union of the the two image shapes with composite image obscuring image in the region of overlap. The matte channel of the composite image is respected, so that if the composite pixel is part or all transparent, the corresponding image pixel will show through.

OverlayCompositeOp

Multiplies or screens the colors, dependent on the destination color. Source colors overlay the destination whilst preserving its highlights and shadows. The destination color is not replaced, but is mixed with the source color to reflect the lightness or darkness of the destination.

PegtopLightCompositeOp

Almost equivalent to SoftLightCompositeOp, but using a continuious mathematical formula rather than two conditionally selected formulae.

PinLightCompositeOp

Similar to HardLightCompositeOp, but using sharp linear shadings, to similate the effects of a strong 'pinhole' light source.

PlusCompositeOp

The result is just the sum of the image data. Output values are cropped to 255 (no overflow). This operation is independent of the matte channels.

ReplaceCompositeOp

The resulting image is image replaced with composite image. Here the matte information is ignored.

SaturateCompositeOp

Each pixel in the result image is the combination of the saturation of the target image and the hue and brightness of the composite image.

ScreenCompositeOp

Multiplies the inverse of each image's color information.

SoftLightCompositeOp

Darkens or lightens the colors, dependent on the source color value. If the source color is lighter than 0.5, the destination is lightened. If the source color is darker than 0.5, the destination is darkened, as if it were burned in. The degree of darkening or lightening is proportional to the difference between the source color and 0.5. If it is equal to 0.5, the destination is unchanged. Painting with pure black or white produces a distinctly darker or lighter area, but does not result in pure black or white.

SrcAtopCompositeOp

The part of the source lying inside of the destination is composited onto the destination.

SrcCompositeOp

The source is copied to the destination. The destination is not used as input.

SrcInCompositeOp

he part of the source lying inside of the destination replaces the destination.

SrcOutCompositeOp

The part of the source lying outside of the destination replaces the destination.

SrcOverCompositeOp

The source is composited over the destination.

SubtractCompositeOp

The result of composite image - image, with underflow wrapping around (mod 256). The add and subtract operators can be used to perform reversable transformations.

VividLightCompositeOp

A modified LinearLightCompositeOp designed to preserve very stong primary and secondary colors in the image.

XorCompositeOp

The result is the image data from both composite image and image that is outside the overlap region. The overlap region will be blank.