DynaPDF Manual - Page 658

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Function Reference
Page 658 of 839
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.
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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