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Converting PDF to TIFF, color management

Posted: 2010-02-24T12:39:52-07:00
by MARTES
Hello!

We try to convert files from PDF to TIFF using "convert" command:

Code: Select all

# convert -density 72 test.pdf -colorspace cmyk test.tiff
After converting file to "test.tiff" colors does not match to colors in "test.pdf" :( What is wrong?
yellow color is CMYK(0%, 4%, 74%, 0%), must be CMYK(0%, 0%, 100%, 0%),
black color has the matched value CMYK(0%, 0%, 0%, 100%).

used files:
http://www.martes.de/test.pdf
http://www.martes.de/test.tiff

Thanks for any ideas/support :)

Re: Converting PDF to TIFF, color management

Posted: 2010-02-24T12:43:33-07:00
by fmw42
does the pdf have an image that is cmyk already? if so

convert -density 72 -colorspace RGB image.pdf image.tif


Also best colormatching uses profiles. see http://www.imagemagick.org/Usage/formats/#profiles

When I try your image, I get errors. Perhaps my gs device needs changing.

convert -density 72 test.pdf test.tif
Unknown device: bmpsep8
Unrecoverable error: undefined in .uninstallpagedevice
Operand stack:
defaultdevice
convert: Postscript delegate failed `test.pdf': No such file or directory @ error/pdf.c/ReadPDFImage/638.
convert: missing an image filename `test.tif' @ error/convert.c/ConvertImageCommand/2919.

Anyone know how to fix this error? Is this a windows only device?


OK, the suggestion is to add -colorspace RGB before reading the image as above. But when I do that I get another error:

convert -colorspace RGB test.pdf test.tiff
**** Warning: File has an invalid xref entry: 2. Rebuilding xref table.

**** This file had errors that were repaired or ignored.
**** The file was produced by:
**** >>>> itext-paulo-155 (itextpdf.sf.net-lowagie.com) <<<<
**** Please notify the author of the software that produced this
**** file that it does not conform to Adobe's published PDF
**** specification.


Nevertheless, it does produce test.tif which looks to me the same as test.pdf