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Problem with antialias when converting PDF to Images
Posted: 2017-01-15T04:57:58-07:00
by LittleKI
Hi,
i use this command line
Code: Select all
convert -density 300x300 -units pixelsperinch input.pdf -background white -alpha background -alpha off -compress zip +adjoin output.tiff
to convert PDF into Images. This works good for teh most files. But there is a problem with antialias (i think). When i zoom in the output image i see that the letters in the tiff image don't have so straight edges as in the pdf file. here is a example, the left is the pdf, the right the tiff:
Datei von filehorst.de laden (The website is in german in my browser, i hope there is a english version when the system language is set to english).
as i could read here
http://www.imagemagick.org/Usage/antialiasing/ antialias should be enable by default.
Re: Problem with antialias when converting PDF to Images
Posted: 2017-01-15T05:20:40-07:00
by snibgo
Anti-aliasing is implemented in alpha, which you turn off, so you remove anti-aliasing. Try this:
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convert in.pdf -background White -layers flatten out.png
Re: Problem with antialias when converting PDF to Images
Posted: 2017-01-15T05:35:40-07:00
by LittleKI
This creates one tiff file with all sites of the pdf document in that one tiff.
Re: Problem with antialias when converting PDF to Images
Posted: 2017-01-15T05:37:23-07:00
by snibgo
Then use "+adjoin".
Re: Problem with antialias when converting PDF to Images
Posted: 2017-01-15T05:54:28-07:00
by LittleKI
Result is the same with +adjoin
Code: Select all
convert -density 200x200 -units pixelsperinch input.pdf -background White -layers flatten -compress zip +adjoin output.tiff
But alos without '-alpha off' the result isn't very good when i zoom in the output tiff. For that i tried this command line
Code: Select all
convert -density 200x200 -units pixelsperinch input.pdf -compress zip +adjoin output.tiff
and this
Code: Select all
convert -density 200x200 -units pixelsperinch input.pdf -antialias -compress zip +adjoin output.tiff
Re: Problem with antialias when converting PDF to Images
Posted: 2017-01-15T06:06:35-07:00
by snibgo
What version of IM are you using? What version of Ghostscript? Please post a link to input.pdf.
Re: Problem with antialias when converting PDF to Images
Posted: 2017-01-15T06:24:24-07:00
by LittleKI
i've tested this with this free eBook:
http://freebooks.pupilgarage.com/FreeBo ... bookid=201
My IM-Version is
and Ghostscript is
Re: Problem with antialias when converting PDF to Images
Posted: 2017-01-15T06:40:26-07:00
by snibgo
Does this do what you want:
Code: Select all
convert -density 200 -units pixelsperinch -background White A_Christmas_Carol_NT.pdf -compress Zip +adjoin acc.tiff
Re: Problem with antialias when converting PDF to Images
Posted: 2017-01-15T08:56:59-07:00
by LittleKI
The same bad results.