Negate

This operation negates the colors in an image. i.e., for 1-bit images, white pixels will be replaced with black ones and black pixels will be replaced with white ones. Gray and RGB images will replace each value with v' = (255 - v); for color images, each color plane will be independently inverted. This replacement will be done by changing the pixel bits within each image line, not by modifying the image palette.

Peg → PegNegate

The uncompressed image to be processed must reside in the Get Queue prior to REQ_EXEC. Typically, the image will be fully contained in the Get Queue, but that is not a requirement. The output image will be placed into the Put Queue during REQ_EXEC.

Padding pixels present at the end of each line may be modified by this operation if the Get and Put Queues refer to different locations in RAM. If both queues occupy the same RAM (causing the operation to be performed in-place), padding pixels will not be modified.

Subcode is set to SF_SUBCODE_NEGATE (6).
Stride is set to the image line width in bytes including padding at the end of the line width or to 0. If Stride is 0 and PF_NoDibPad is set in PicFlags, the operation will compute the stride using: [ (PixelWidth*BitCount)/8 ]. If Stride is 0 and PF_NoDibPad is not set in PicFlags, the operation will compute the stride using: [ (((PixelWidth*BitCount)+31)&(~31))/8 ].

In addition to placing an output image into the Put Queue, this operation stores some output information into the PIC_PARM structure in the following locations.

OutputStride is set, during REQ_INIT and REQ_EXEC, to the image line width in bytes including padding at the end of the line.
BiOut is set, during REQ_INIT and REQ_EXEC, to the attributes of the output image. Since this operation does not adjust the size of the image, BiOut will be set to a copy of the Head structure within PIC_PARM.