Auto-Despeckle

Analyze a 1-bit image and removes black specks.

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.

This subcode differs from the Despeckle subcode (1) in that the speck size is not explicitly set. Rather, the opcode analyzes the image to determine a typical character size and does not remove marks large enough to be characters. Discrimination is based on other criteria as well as size so that a dot of a given size may be removed if it is judged to be a random speck or retained if it is judged to be a punctuation mark or part of a character.

Subcode is set to SF_SUBCODE_AUTO_DESPECKLE (51).
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 ].
No other parameters need to be set.

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.

CountOfFeaturesDetected is set, during REQ_EXEC, to the number of specks removed.
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.