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This article is from September 5, 2001, and is no longer current.

Out of Gamut: Setting Up Color Management in Photoshop 6

Warnings
In addition to selecting policies within Color Settings, in that same dialog box you can and should configure warnings for three separate situations. The warnings not only notify you of the situations, they also let you take some remedial action. Let’s take a look at these:
Profile Mismatches: Ask When Opening: This warning alerts you when an image has an embedded profile that differs from the current working space, and lets you take one of three actions:

  • Use the embedded profile (instead of the working space) opens the image in the embedded profile’s space. In effect, it uses the embedded profile as the working space for that image. If in doubt, this is usually the option to choose. You can always convert it to some other space after you’ve seen the image.
  • Convert document’s colors to the working space converts the image from the embedded profile’s space to the working space. You might want to choose this option when you open an image from a scanner that embeds its profile correctly. Scanner spaces are generally not suitable for editing, so if the image needs work, you’re typically better off converting it into a working space.
  • Discard the embedded profile (don’t color manage) is probably the least useful of the three. It can be a handy choice if you’re dealing with a calibration target, where all you care about are the numbers in the file, or in a closed-loop CMYK workflow where you intend to edit the image, and only care about what the numbers will look like in your preferred CMYK working space.

Profile Mismatches: Ask When Pasting: This action kicks in when you try to transfer pixels between two documents in different color spaces but in the same color mode (that is, two different flavors of RGB or of CMYK, for example). In this situation, Photoshop needs to know whether you want to transfer the actual numbers (which will likely mean that the transferred pixels will change color appearance), or paste the colors that these numbers represent in the source document.

  • Convert (preserve color appearance) converts the pixels being moved from the source document’s space to the target document’s space, preserving the color appearance.
  • Don’t convert (preserve color numbers) moves the pixel values with no conversion. They thus take on the appearance dictated by the target document’s space. If you turn off this warning, the default behavior is that Photoshop preserves the color appearance when moving pixels between RGB documents, and preserves the color numbers when moving pixels between CMYK documents.

Missing Profiles: Ask When Opening: This option alerts you when the image you’re opening doesn’t contain a profile, and it offers you four choices for dealing with the omission. Since untagged files (those that don’t contain profiles) are basically “mystery meat” in terms of color, there’s no single correct way to deal with them unless you know something about the source. A strategy for dealing with mystery-meat files is really a topic deserving of its own future column, but for now, here are the options.

  • Leave as is (don’t color manage) treats the image as untagged, which means that Photoshop treats it as being the current working space. As a result, even though the numbers in the image remain unchanged, the appearance changes a little, or a lot, depending on how different the embedded profile space was from your current working space.
  • Assign working RGB/CMYK/Gray produces a visually and numerically identical result to the first option, the subtle difference being that untagged images are always interpreted according to the current working space: If you change the working space, you change the appearance of untagged images. In contrast, an image that’s been assigned a profile stays in that profile space even if you subsequently change the working space.
  • Assign profile lets you assign any profile to the image, the only constraint being that the profile must be one for the image’s color mode. Photoshop won’t let you assign an RGB profile to a CMYK image, or vice versa. If you know the source of an image or can make an educated guess about it, you can use this option to assign a profile to it. For example, if your scanner software doesn’t embed profiles but you have a profile for the scanner, and you know the image came from the scanner, you can assign the scanner profile here.
  • Assign Profile and convert document to working RGB/CMYK/Gray lets you assign a profile, as in the previous option, and then convert the image from that profile’s space to your working space. If you know the image’s source, and you know that you want to convert the image to your working space for editing, this can be a useful option, but if you’re in doubt it’s best avoided.

The safest starting point is to set all Color Management Policies to Preserve Embedded Profiles, and to turn all warnings on. The other two policies change either the numbers in the images or the interpretation of those numbers automatically, which is great if that’s something you understand and want to happen, but confusing at best and disastrous at worst when you don’t. The warnings give you a moment’s pause to consider the situation, and to act accordingly.


Setting the Color Management Policies as shown in the bottom half of the dialog (above) should work best for most circumstances.

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Bruce Angus Fraser (9 January 1954 – 16 December 2006) was an author who specialized in digital color technology, including hardware and software for creating and managing color images and publications. He co-authored "Real World Photoshop" and others. He was a founding member of PixelGenius, LLC.
  • anonymous says:

    When are we going to get part 2??

  • anonymous says:

    Simplifies a complex subject

  • anonymous says:

    I’ve been struggling with understanding this–Bruce Fraser has been a great help! Thank you.

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