Examine a single pixel map

#include <PictUtil.h> Picture Utilities

OSErr GetPixMapInfo(thePixMapHandle, thePictInfo, verb,

colorsRequested, colorPickMethod, version);

PixMapHandle thePixMapHandle; is a handle to the pixel map record to be

examined

PictInfo *thePictInfo; a pointer to the picture information record

short verb; indicates whether you want colors from the

image returned as a palette or a color table

short colorsRequested; the number of colors you want

short colorPickMethod; indicates what colors to return

short version; Set the version parameter to 0.

returns Error Code; 0=no error

The GetPixMapInfo function examines a single pixel map, returning

information in the picture information record.

thePixMapHandle a handle to the pixel map record to be examined

thePictInfo a pointer to the picture information record that will hold the

verb indicates whether you want colors from the image returned as a

palette or a color table by setting the returnPalette or

returnColorTable bit of the verb. You may set both bits, in

which case you will get both a color table and a palette. You can

also specify suppressBlackAndWhite in the verb parameter to

request that black and white not be counted when surveying

colors. (Since the Palette Manager adds black and white when

creating a palette, this technique can be useful when you are

sampling colors destined for a palette or the screen: ask for the

number of colors you want minus 2, and suppress black and

colorsRequested specifies the number of colors you want returned in the palette

or color table; it may be from 1 to 256.

colorPickMethod indicates what colors to return. If you specify popularMethod,

GetPixMapInfo returns the colors used most frequently. If you

specify medianMethod, GetPixMapInfo returns a weighted

distribution of colors. If you specify systemMethod, the

Picture Utilities Package chooses the more appropriate.

You can also create your own color-sampling method, as described

own method, specify its resource ID in the colorPickMethod

parameter. The ID must be in the range from 128 to 32768. The

Returns: an operating system Error Code.

pictInfoVersionErr (-11000) Version number not 0

pictInfoVerbErr (-11002) Invalid verb combination specified

cantLoadPickMethodErr (-11003) Custom pick method not in resource chain

colorsRequestedErr (-11004) Number out of range or greater than passed to

Notes: GetPixMapInfo can potentially move and purge memory.