Re: RGB colorspace question

Bob Friesenhahn <[email protected]> Mon, 8 Jan 2024 15:44:36 -0600 (CST)
Newsgroups gmane.comp.video.graphicsmagick.help
Message-ID <[email protected]>
On Fri, 5 Jan 2024, Michael Orlitzky wrote:

> On Fri, 2024-01-05 at 18:14 -0600, Bob Friesenhahn wrote:
>> The most likely cause of the difference is if the PNG has an embedded ICC
>> CMS profile, or is marked to be in an unusual colorspace.  Perhaps
>> ImageMagick is applying a colorspace transformation.
>>
>> Try doing
>>
>> convert infile -strip -colorspace rgb foo.txt
>>
>
> This produced the same output (as it did without -strip) in both
> graphics and imagemagick.

Besides colorspace transformation, there is also the possibility of a 
gamma adjustment.  A gamma adjustment will also cause a change in 
numeric levels.

Bob
-- 
Bob Friesenhahn
[email protected], http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/
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