Legacy ImageMagick Discussions Archive

Hello!
I would ike to convert a cmyk-jpg to pdf. This is my command:
convert pic.jpg -units PixelsPerInch -density 254x254 pic.pdf

These are samples of input jpg and output pdf:
input
output

The pdf image looks quite weird, as it has lost a lot of colors, or something like that.

I have almost no experience in all this image stuff, and I'm quite new to imageMagick... could someone please point me to what I'm doing wrong?
Thank you very much!

Markus Braun


These are the actual images:
input jpg
output pdf

The problem could be that you have an input file with a color profile ("ISO Coated v2 300% (ECI)"). The PDF still has the JPG with this color profile, but a PDF viewer won't access the profile this way. And ImageMagick creates the PDF 'only' with a general /DeviceCMYK colorspace. So, your original color profile is not used when the PDF has to be displayed in another colorspace (usually, "US Web Coated SWOP v2" is used as a general source color profile for CMYK data).

Some possibilities:

- You can access the correct CMYK data with Ghostscript. Example: The second IM command is just for assigning the correct color profile again.

- The PDF should display correctly in a program that allows you to set a CMYK working space - with your original color profile (probably with Acrobat).

- Or you could convert your CMYK image to "US Web Coated SWOP v2" first (if you have the profile). Example: Not an ideal solution, but the PDF from ImageMagick should look ok (in every PDF viewer) after that.

For an even better solution, the PDF would have to be created with an /ICCBased object (where the color profile from the input image can be specified). I don't think that ImageMagick is able to do that.

Thank you for your help!
I'll need some time to try this, and some more to understand it...
I'll post again later.


EDIT:
Thank you very much again, but I had to realize that all this profiles and colorspaces stuff is way to far ahead for me. I will have to go another way.

Thanks again,
Markus