Auto-Remove Dot Shading

Removes areas of shading from one-bit images similar to SF_SUBCODE_REMOVE_DOT_SHADING (17), though will be more robust in general. No parameters are required; the tool is fully automatic. Text in shaded areas as well as line-art around or within the shaded region will be preserved in general. This operation may fail if the text itself is damaged by many white inclusions.

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.

No parameters are required to start the dot shading removal; the algorithm is completely automatic. Future versions may include additional parameters.

Subcode is set to SF_SUBCODE_AUTO_REMOVE_DOT_SHADING (59).
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.