Bug #96204 for Imager: CMYK JPGs are converted to RGB, messing with colors

Wed Jun 04 04:37:15 2014 JKRAMER [...] cpan.org - Ticket created

Subject:

CMYK JPGs are converted to RGB, messing with colors

When I read a JPG with CMYK color space, it seems to be converted to RGB automatically when being written (regardless of the output format), leading to colors to be off. I can't find a way to change this behavior or set the color space to CMYK explicitly when writing. To reproduce, save the attached sample JPG and run: perl -MImager -e 'Imager->new(file => "orig.jpg")->write(file => "copy.jpg")'

Subject:

orig.jpg

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Wed Jun 04 05:30:18 2014 tony [...] develop-help.com - Correspondence added

Subject:	Re: [rt.cpan.org #96204] CMYK JPGs are converted to RGB, messing with colors
Date:	Wed, 4 Jun 2014 19:30:04 +1000
To:	Jonas Kramer via RT <bug-Imager [...] rt.cpan.org>
From:	Tony Cook <tony [...] develop-help.com>

On Wed, Jun 04, 2014 at 04:37:16AM -0400, Jonas Kramer via RT wrote: Show quoted text

> When I read a JPG with CMYK color space, it seems to be converted to RGB automatically when being written (regardless of the output format), leading to colors to be off. I can't find a way to change this behavior or set the color space to CMYK explicitly when writing. > > To reproduce, save the attached sample JPG and run: > > perl -MImager -e 'Imager->new(file => "orig.jpg")->write(file => "copy.jpg")'

Hi Jonas, Unfortunately this isn't likely to change soon. Imager only supports RGB and greyscale images internally, so any images need to be converted to one of those colourspaces. Right now Imager uses a very primitive CMYK to RGB conversion, I plan to change that, but it requires a lot of pre-requisite work which won't be happening quickly. Tony

Wed Jun 04 05:30:18 2014 The RT System itself - Status changed from 'new' to 'open'

Fri Jun 13 06:52:45 2014 TONYC [...] cpan.org - Priority changed from (no value) to '30'