Monitor Preparation for Image Processing

For image processing your monitor should be set to its Custom preset mode with the calibration profile loaded. This maximizes the monitor's ability to render properly any image you load (especially if it is a wide gamut monitor), so long as any color space mismatches are properly managed. You then deal with viewing all images in this "universal" space by color managing them in software as described following. For most photo work this process is automatic but you should be alert for the exceptions and the alternatives available.

Software Settings

Photoshop, Paintshop, Picture Window, etc. all have an option for setting "Color Working Space" (CWS). What this means is that the software can be made to temporarily over-ride the monitor color space with another one and it is that new color space in which the image will be viewed for processing (subject to the possibility of Color Space mis-matches). The software will now color manage the working space into the monitor space using "rendering intent" as necessary. If the monitor space is the same as or larger than the chosen working space, what you see will be as it was meant to be in the working space. Of course, the monitor CS can also be chosen as the CWS but as this is typically a non-standard specification I prefer not to do that.

The general rule is that the CWS should match the image color space. Alternatively, choose the option that causes the software to temporarily use the color space of the image. The only exception would be where you actually want to convert an image from one color space to another.

If the embedded CS of an image does not match the CWS you get a "Color Space Mismatch". You and/or the software then have to make some decisions. These could include "ignore", "convert", "change the CWS temporarily to match the image", "throw out the image CWS". You will need to know the implications. In Photoshop you can automate the decision making which makes sense provided you know what you are doing. Usually you will want "change the CWS temporarily" with "convert" as a more drastic alternative. "Ignore" and "Throw out" are perplexing. These say "Let's forget about Color Management altogether".

Unfortunately, the software makers use different terminology and the "rules of engagement" are sometimes confusing. I like to pick on Photoshop once in awhile but in my opinion they are the only ones who deal with CWS in a way that makes total sense. Let's try going through this step by step.

• Find where your software provides the CWS settings. In Photoshop it's under "Edit" but in Paintshop it is under "File/Preferences". You are on your own with other packages. This crucial sort of thing ought to be in a standard place but it isn't.
• Set the notification/conversion options. In Photoshop you can have Color Spaces automatically converted in event of mismatches. I consider this a bit dangerous as a default. There are many options here but my objective is to deal only with the fundamentals. I request being notified. Paintshop always notifies you. It had better because it likes to force convert color spaces in event of mismatches.

Now things get tricky depending on what package you are using. I will deal with just two so you can appreciate the situation. Ket's assume you will now have open the Edit/Color Settings panel in Photoshop. Note: CWS = Color Working Space and CS = Color Space (in general).

Photoshop CS4

The following are my preferencs, supporting maximum flexibility and requiring manual intervention when profile mismatches occur.

Case 1: In "Settings", choose the "Custom" option. This affords the best flexibility.  Note that if you explicitly choose "Monitor Color" from the drop-down list, CS4 will NOT color manage. It is unclear why this is so but it does provide you an additional choice of viewing the image as if it were already in the monitor CS. If you want the image properly color managed inside the monitor CS so as to reflect the embedded CS, choose "Custom" and then in the "RGB" panel immediately below, pick the file name for the monitor profile from the drop-down list.

In "Color Management Policies" it is usually a good idea to check all "Preserve embedded Profiles" unless your aim is to do automated CS conversions.

I also click the boxes for "Profile Mismatches" and "Missing Profiles". This produces warnings when loading an image and gives you a list of response options.

Since the CWS is now device specific, every time you load an image you will be notified of a Color Space mismatch and given some Color Management options (unless you decided to have the choice automated):

1. Discard the embedded profile. The image's embedded will quite literally be removed and the image will be displayed and treated with as if its space is the CWS (monitor). When you are finished, the image will be saved without an embedded color space but you can always provide one later. I am not sure why you would want to use this option.
2. Temporarily use the image CS. Photoshop will color manage the monitor so that you see the image as intended in its own CS. This would be by far the most common choice in case of a CS mismatch. When you save, the embedded image CS is preserved.
3. Convert the image to the CWS. This will attempt to preserve image appearance by changing the numbers in the image file. The image embedded CS is changed to the CWS. If the monitor color space is the larger of the two, the image may benefit from your being able to edit colors more extensively.
4. Assign CWS. In case there is no embedded profile. This is most likely to happen with RAW images. If you know you are going to be processing a set of RAWS, set the CWS to the CS you would like these images to have when processed into TIFFs or JPEGs. This should match the camera CS setting.

Case2: Setup as in Case 1 but in the RGB panel immediately below "Settings" choose a standard profile (color space). Probably the best choice if all project images are in the same CS. This avoids having the CS mismatch panel pop up every time you load an image. On the whole I prefer this approach, even with RAWs where a CS may have to be assigned. It is probably better simply as an approach to standardization to have your images created inside a known CS rather than the device specific monitor CS. aRGB is the preferred standard space. If you get a mismatch by loading an sRGB image you can always choose having CS4 temporarily work in sRGB as in choice "2" above.

This is very straightforward but if you should load an image with an embedded CS other than the CWS you will get the CS Mismatch panel and you are once again having to consider the several choices above unless you automated the response.

Case3: Choose any other CWS from the list you will be shown. I have never used this but it might be useful for preparing an image for a device you do not have or for working in proof mode (image managed to appear as it will on your printer). There will be CS mismatch for each image you load so it's the three choices above once more or automatic response of that's what you selected.

Paintshop Pro

Similar to Photoshop but note the following critical differences:

• When there is a CS mismatch does NOT offer option 2. You are informed it is converting the image to the CWS. Period. You can cancel but you cannot temporarily work in the image CS. Bummer. If you don't want conversion you have to reset the CWS to the image CWS.
• The equivalent to option 1 is to "ignore" the embedded profile. The profile is not removed. Seems to me that if you now edit the image (which will be rendered in the CWS) you will have a mismatch between the embedded profile and the new intended appearance. This could prove misleading.

In Paintshop you should probably just set the CWS to the image CS for most work. That is, use Case 2. I really do not care for their way of dealing with CS mismatches unless, of course, you do not mind CS conversion.

I don't intend at this time venturing into peculiarities of Silkypix or Picture Window but they are there.

Bottom Line(s)

• There are differences in the way various packages implement color management. This is annoying and fraught with pitfalls if you use more than one package.
• It is important to choose and know what Color Working Space (CWS) you are using. Depending on implementation, choice of CWS will invoke various Color Management processes either automatically or as choices to be made each time a color space mismatch occurs.
• When editing/processing images we normally want to work in the original, embedded Color Space of the image even though the monitor Color Space may be different. This is very straightforward. Should a Color Space mismatch occur, you can set Photoshop to do an automatic conversion or to work in the image's CS (preferred, i.e., color manage the monitor). Alternatively, you can configure Photoshop to present you with choices each time.  Paintshop offers only hard conversion with no automation option when a CS mismatch occurs. You can authorize it to proceed or Cancel.
• For the monitor choose the largest CS the unit will support (as a Custom Setting in CS4) and color manage everything inside that. This maximizes accuracy of what you see with a mix of input Color Spaces. This space will almost always be the one in the profile created by your monitor calibration process.
• For CWS, use the largest standard CS supported within the monitor CS. For Wide gamut monitors today this will usually be aRGB. sRGB images loaded into this space will be correctly rendered by color management if you preserve the embedded profile when asked. An exception is if preparing images for Internet viewing. For this purpose you should choose conversion to sRGB and use an sRGB CWS.

There are other ways but this works perfectly for me.

Note Concerning Images Arriving on the Internet:

If you are in receipt of Internet images without embedded profiles or if you are using a non-color managed OS (Windows prior to Vista) you will obtain best visual results by switching the monitor to sRGB for Internet viewing. This option may be available as a physical control on the monitor itself or you could load an sRGB profile using Control Panel.

On color managed systems (Vista, WIndows 7, Mac) the monitor can stay in native profile (custom) mode. Images with profiles (which will be the vast majority these days) will be properly managed into that CS and you can forget about what color space they live in.

Proofing

I suspect a lot of photographers overlook this handy tool. Proofing works. It's a feature whereby the imaging software color manages your image into the color space of printer+chosen paper and then into the Color Working Space you use for viewing. That way you can better visualize how the printed image will actually look. This can provide a quite accurate impression concerning outcome, including brightness and color balance. Ideally, your un-proofed monitor image should be all you need but in reality, differences between screen and paper still occur. Proofing can sometimes provide that extra bit of accuracy in determining what those differences might be before committing to ink.

Proofing is easy to set up and there's no need to explore the details here.