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Managing Color With ColorSync


Color Rendering Dictionary Virtual Memory Size

The ColorSync Manager defines the CMIntentCRDVMSize type for specifying the maximum virtual memory size of a color rendering dictionary.


CMIntentCRDVMSize

To specify the maximum virtual memory (VM) size of the color rendering dictionary (CRD) for a specific rendering intent for a particular PostScript Level 2 printer type, a printer profile can include the optional Apple-defined 'psvm' tag. The PostScript CRD virtual memory size tag structure's element data includes an array containing one entry for each rendering intent and its virtual memory size.

If a PostScript printer profile includes this tag, the default CMM uses the tag and returns the values specified by the tag when your application or device driver calls the function CMGetPS2ColorRenderingVMSize .

If a PostScript printer profile does not include this tag, the CMM uses an algorithm to determine the VM size of the CRD. This may result in a size that is greater than the actual VM size.

The CMIntentCRDVMSize data type defines the rendering intent and its maximum VM size. The CMPS2CRDVMSizeType data type for the tag includes an array containing one or more members of type CMIntentCRDVMSize.

struct CMIntentCRDVMSize {
    long            renderingIntent;    /* rendering intent value */
    unsigned long   VMSize;             /* virtual memory size of CRD */
};

Field descriptions

renderingIntent
The rendering intent whose CRD virtual memory size you want to obtain. The following rendering intent values are described in Rendering Intent Values for Version 2.x Profiles :

0 (cmPerceptual)
1 (cmRelativeColorimetric)
2 (cmSaturation)
3 (cmAbsoluteColorimetric)


Field descriptions

VMSize
The virtual memory size of the CRD for the rendering intent specified for the renderingIntent field.

CMPS2CRDVMSizeType

The CMPS2CRDVMSizeType data type defines the Apple-defined 'psvm' optional tag.

struct CMPS2CRDVMSizeType {
    OSType              typeDescriptor; /* PostScript VM signature */
    unsigned long       reserved;       /* reserved */
    unsigned long       count;          /* entries in CRD array */
    CMIntentCRDVMSize   intentCRD[1];   /* variable-sized array */
};

Field descriptions

typeDescriptor
The 'psvm' tag signature.
reserved
Reserved for future use.
count
The number of entries in the intentCRD array. You should specify at least four entries: 0, 1, 2, and 3.
intentCRD
A variable-sized array of four or more members defined by the CMIntentCRDSize data type.

© 1988-1999 Apple Computer, Inc. — (Last Updated 20 Jan 99)