DynaPDF Manual - Page 642

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Function Reference
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In order to compress the image with CCITT Fax 4, for example, and to apply a simple ordered
dithering algorithm, combine the compression filter and dithering flag with a binary or operator,
e.g. TCompressionFilter(cfCCITT4 | cfOrderedDithering).
Anti-Aliasing should be disabled when creating 1 bit images to avoid anti-aliasing artifacts.
The Otsu filter is useful if an OCR scan should be applied on the resulting 1 bit image. Most OCR
engines produce best results with this filter.
If the output format is Bitmap (BMP) the compression filter is used only to determine whether a
dithering algorithm should be applied. The compression filter can be set to any of the above values.
Remarks:
This function is available in an Ansi and Unicode compatible version. Unicode file paths are
converted to UTF-8 on non-Windows operating systems.
Return values:
If the function succeeds the return value is 1. If the function fails the return value is 0.
 

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