Controls to tweak sharpness of rasterized PDF

[Ivan N]

Q: When rasterizing a PDF with a lot of text , like standard Magazine
pages, having some controll over the sharpness off the image is
needed.

Now we do some post processing with ImageMagick , having this in your
product would be great.

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A:

PDFTron built-in rasterizer (see pdftron.PDF.PDFDraw;
http://www.pdftron.com/pdfnet/samplecode.html#PDFDraw) includes some
options to affect aliasing. For example, you could use
PDFDraw.SetGamma(exp) or --gamma (in PDF2Image CLI) to tweak the
exponent value of gamma function.

Typical values are in the range from 0.1 to 3. Gamma correction can be
used to improve the quality of anti-aliased image output and can (to
some extent) decrease the appearance common anti-aliasing artifacts
(such as pixel width lines between polygons).

Other than this you could also increase the resolution at which you
are rendering PDF (using SetDPI() or --dpi).

Please let me know if this helps.