mask

Image mask. Specifies a separate mask image to be used as an unassociated mask.

mask= *object*|{[is|ir]'{' *nestedRequest*'}'}

object may be either a catalog entry or an image/SVG file. Can be specified for image layers and solid color layers.

If object resolves to an image catalog entry, catalog::MaskPath is used, or, if catalog::MaskPath is not defined, then catalog::Path is used. If object does not resolve to a catalog entry, then it is interpreted as a file path.

In all cases, if the source image has an alpha channel, it is used. Otherwise, the image is converted to grayscale, if necessary, before using it as a layer mask.

If a mask is attached to a solid color layer, it can be cropped and scaled using the same rules used for images in image layers. size=, scale=, or res= can be used to scale the mask.

Layer masks can also be specified in form of a nestedRequest. Nested or embedded requests are enclosed by curly braces. Prefix an embedded Image Serving request with is and an embedded Image Rendering request with ir. A request to a foreign server is assumed if no prefix is specified. Refer to Request Nesting and Embedding for details.

Properties

Image or layer attribute. Applies to layer 0 if layer=comp. Ignored by effect layers.

object must not resolve to a catalog record which includes a src= or mask= command in catalog::Modifier.

The is and ir prefixes are case-insensitive.

Default

If mask= is not specified explicitly, and if the layer image is associated with a catalog entry, then catalog::MaskPath is used. Otherwise, the alpha channel of the layer image is used, if present. If there is no alpha channel, the layer has no mask and the layer rectangle is rendered entirely opaque.

Example

Use several separate masks to colorize different areas of an image. The colorized, masked regions is layered on top of the original, unmodified image:

http://server/myRootId/myImageId?wid=500& layer=1&src=myImageId&mask=myMask1&op_colorize=200,0,0& layer=2&src=myImageId&mask=myMask2&op_colorize=0,200,0& layer=3&src=myImageId&mask=myMask3&op_colorize=0,0,200

See also

maskUse= , catalog::MaskPath, object , Request Nesting and Embedding