>> I open up an image to make a small change to one corner. Why did other
>> parts of my image change color slightly? Because Round tripping through
>> color profile is not lossless (some profiles are worse than others).
> Well, that's certainly true. Though open/edit/save, at least for
> JPEGs, will always change the image slightly, even in applications
> that support device space editing. It's a question of how significant
> the differences are.
A professional will do anything possible to avoid going through multiple
jpeg compression steps, and certainly wouldn't use software that required
it as part of the workflow.
Converting to/from synthetic color spaces like sRgb and AdobeRGB will be
lossless aside from very minor numerical rounding issues.
Converting to/from real world measured color profiles will result in
visible differences after the first round trip, and will generally be
unusable without significant correction after 2 or 3.
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