Setting Default Color Space Profiles and the Preferred CMM

The ColorSync Control Panel

The ColorSync control panel replaces the ColorSync^TM System Profile control panel. The ColorSync panel, with its default settings, is shown in The ColorSync control panel .

Figure 2. The ColorSync control panel

Setting Default Color Space Profiles

ColorSync previously supported only one default profile--the RGB "System" profile. Users can now use the ColorSync control panel to set default profiles for RGB and CMYK color spaces as well. For information on how to get and set the system profile, and how to get and set default profiles for the RGB, CMYK, Lab, and XYZ color spaces, in your code, see Default Color Space and System Profile Functions .

Setting the Preferred CMM

The ColorSync control panel lets you choose a preferred CMM from any CMMs that are present (registered with the Component Manager).

If you choose a preferred CMM with the ColorSync control panel, and if that CMM is available, ColorSync will use that CMM for all color conversion and matching operations. If you specify "Automatic" instead, or if your specified CMM is no longer present or cannot provide the required matching service, ColorSync follows an algorithm described in .Advanced Color Imaging on the Mac OS to determine which available CMM to use for matching.

Your code can call the CMGetPreferredCMM function to get the preferred CMM. The function is defined as follows:

pascal   CMError   CMGetPreferredCMM (
                   OSType *cmmType,
                   Boolean *preferredCMMnotfound)

cmmType	A pointer to an OSType. On return, the component subtype for the preferred CMM. For example, the subtype for the default CMM provided by Apple is 'appl' and the subtype for the Kodak CMM is 'KCMS'. A return value of nil indicates the preferred CMM in the ColorSync control panel is set to Automatic.
preferredCMMnotfound	A pointer to a Boolean flag for whether the preferred CMM was found. On return, has the value true if the CMM was found. false if it was not.
function result	A result code of type OSErr. See Advanced Color Imaging on the Mac OS for a list of ColorSync-specific result codes. Always check the function result before using any information returned in the function parameters.

The CMGetPreferredCMM function returns in the cmmType parameter a value that identifies the preferred CMM the user last specified in the ColorSync control panel. CMGetPreferredCMM returns true in the preferredCMMnotfound parameter if the preferred CMM is currently available and false if it is not. For example, a user may specify a preferred CMM in the ColorSync control panel, then reboot with extensions off. ColorSync does not change the preferred CMM setting when the preferred CMM is not available.