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carlos_mendoza
Participant
April 8, 2016
Answered

is Assigning Color Profiles A Permanent Action?

  • April 8, 2016
  • 4 replies
  • 2686 views

Assigning color profiles is a permanent/destructive action? I mean, is it possible to change a color profile with no permanent changes in the original file?

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Correct answer TheDigitalDog

carlos_mendoza wrote:

Assigning color profiles is a permanent/destructive action? I mean, is it possible to change a color profile with no permanent changes in the original file?

See: http://digitaldog.net/files/06AssignProfileCommand.pdf

4 replies

Inspiring
April 12, 2016
is it possible to change a color profile with no permanent changes in the original file?

for additional clarity:


Photoshop> Edit> ASSIGN Profile (is the move my Bruce Fraser's text was referring to)

Photoshop> Edit> CONVERT to Profile does change/degrade the color (if the conversion move is saved, the damage is permanent and cannot be recovered.  if the conversion move is not saved, the degradation still occurred in the open document, but is not permanent because it was not saved)


generally use and maintain the original embedded profile (color space) -- convert to a destination profile only as needed -- keep profile conversions to an absolute minimum because the clip or compress color information

Inspiring
April 12, 2016

RENDERING INTENT is the term for how Photoshop (and print utilities) allow us to control the color re-mapping/transformation process during a profile conversion


two common rendering intent options are PERCEPTUAL & RELATIVE COLORIMETRIC


perceptual is said to "compress" the colors into a smaller color space

relative colorimetric "clips" the information and discards it


if you are unsure which rendering intent to use, try each one and compare the results

Inspiring
April 9, 2016

Bruce Fraser summed this up in an Adobe forum:


"You could change profiles a thousand times via Assign Profile and the image would not degrade... inasmuch as the numbers in the file wouldn't change, this is true. But it would display incorrectly, and convert to any other space incorrectly, so it's fair to say that while the integrity of the data hasn't been compromised, and you can rescue the file by assigning the correct profile, for all practical purposes, it's hosed."

TheDigitalDog
Inspiring
April 9, 2016

IF all images were properly tagged with an embedded profile, there would be zero need for the Assign Profile command. Where it's useful and necessary is the rare case that a document has no embedded (tagged) profile; RGB mystery meat as Bruce liked to say. The RGB (or CMYK) values have no scale. It's like asking me how far I live from you and I simply write: 1000. 1000 feet, miles, kilometers? 1000 without a scale has no meaning. As does R34/G99/B200 without an assigned profile to define it's scale, it's color space. Now assign sRGB to the numbers, or Adobe RGB (1998) etc, we have a scale (miles, kilometers etc).

Author “Color Management for Photographers" & "Photoshop CC Color Management/pluralsight"
TheDigitalDog
TheDigitalDogCorrect answer
Inspiring
April 8, 2016

carlos_mendoza wrote:

Assigning color profiles is a permanent/destructive action? I mean, is it possible to change a color profile with no permanent changes in the original file?

See: http://digitaldog.net/files/06AssignProfileCommand.pdf

Author “Color Management for Photographers" & "Photoshop CC Color Management/pluralsight"
D Fosse
Community Expert
Community Expert
April 8, 2016

Assigning a profile does not change the original data. It does change the interpretation of that data, though, so it looks different.

Converting to a profile does change original data, so that's potentially destructive and shouldn't be done unnecessarily.

carlos_mendoza
Participant
April 9, 2016

thanks for the response, does it mean that I can 'label' a file with different color profiles for different output devices? I have only one photo and I have to change it for different outputs and I don't want to make too many digital copies for each color assigning

D Fosse
Community Expert
Community Expert
April 9, 2016

No, it does not. You don't assign for output, you convert.

Keep one master file in a color space large enough to contain all the data, and then you save out copies converted for specific output. No need to keep these copies, they can easily be recreated as needed.