RGB png to CMKY pdf conversion help

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M1C4HTRON13
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RGB png to CMKY pdf conversion help

Post by M1C4HTRON13 »

I have an RGB png 6969x4843 300dpi
I need to convert it to a CMYK pdf with as little quality loss as possible.

Can you help me
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fmw42
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Re: RGB png to CMKY pdf conversion help

Post by fmw42 »

convert image.png -colorspace CMYK image.pdf

or better color quality, by using profiles

convert image.png -profile /path2profiles/USWebCoatedSWOP.icc image.pdf

But, you are just putting a pdf wrapper around a raster image. No quality will be lost, since png is lossless. But you may still have to specify a density when reading the pdf, since pdf format has no true resolution other than the pixels imbedded in it.

You may already have this profile on your system with IM, but if not search the web for it.

see
http://www.imagemagick.org/Usage/formats/#profiles
M1C4HTRON13
Posts: 2
Joined: 2014-01-15T13:28:07-07:00
Authentication code: 6789

Re: RGB png to CMKY pdf conversion help

Post by M1C4HTRON13 »

fmw42 wrote:convert image.png -colorspace CMYK image.pdf

or better color quality, by using profiles

convert image.png -profile /path2profiles/USWebCoatedSWOP.icc image.pdf

But, you are just putting a pdf wrapper around a raster image. No quality will be lost, since png is lossless. But you may still have to specify a density when reading the pdf, since pdf format has no true resolution other than the pixels imbedded in it.

You may already have this profile on your system with IM, but if not search the web for it.

see
http://www.imagemagick.org/Usage/formats/#profiles
Thanks
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fmw42
Posts: 25562
Joined: 2007-07-02T17:14:51-07:00
Authentication code: 1152
Location: Sunnyvale, California, USA

Re: RGB png to CMKY pdf conversion help

Post by fmw42 »

Correction to my post above:

If the png has a profile, then the following is correct.

Code: Select all

convert image.png -profile /path2profiles/USWebCoatedSWOP.icc image.pdf
If it does not have a profile, then you should assume sRGB and use that profile first.

Code: Select all

convert image.png -profile /path2profiles/sRGB.icc -profile /path2profiles/USWebCoatedSWOP.icc image.pdf
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