Color Conversion Problem

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jackieO

Color Conversion Problem

Post by jackieO »

when i convert using -colorspace rgb or -strip -profile /usr/share/color/icc/Adobe\ ICC\ Profiles/RGB\ Profiles/AdobeRGB1998.icc get weird output . . . i am converting from a CMYK pdf to jpg btw

this is the bad file:
Image

any ideas??
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fmw42
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Re: Color Conversion Problem

Post by fmw42 »

I don't think you are changing colorspaces correctly. I think that only works if you start from RGB and go to some other colorspace. I don't think IM knows that your image is CMYK and so you need to tell it in a round about way. See http://www.imagemagick.org/Usage/channe ... bine_other

where you will find something like this:

convert image_cmyk.gif -colorspace CMYK -separate image_cmyk_%d.gif
convert image_cmyk_0.gif -colorspace CMYK \
image_cmyk_0.gif -compose CopyCyan -composite \
image_cmyk_1.gif -compose CopyMagenta -composite \
image_cmyk_2.gif -compose CopyYellow -composite \
image_cmyk_3.gif -compose CopyBlack -composite \
-colorspace RGB image_rgb.jpg

I am not sure that this is causing your diagonal banding issue though! It may be that you are starting with a PDF file and that may be the issue.
jackieO

Re: Color Conversion Problem

Post by jackieO »

with the same setup (imagemagick), the pdf files converted fine on CentOS 4.5 (i386) but when I changed to CentOS 5.1 (x86_64) everything got wacky. What could be the issue. . . .the pdf files are the same . . . ? I bought a 64bit server and went with x86_64 for the speed, but it seems to have crippled me. . . . I am running imagemagick 6.2.8-3 btw.
jackieO

Re: Color Conversion Problem

Post by jackieO »

bump
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