Color Modes

MagickCore, C API: Count the Colors in an Image

Color



AcquireColorCache

AcquireColorCache() caches one or more color configurations which provides a mapping between color attributes and a color name.

The format of the AcquireColorCache method is:

LinkedListInfo *AcquireColorCache(const char *filename,
  ExceptionInfo *exception)

A description of each parameter follows:

filename
the font file name.
exception
return any errors or warnings in this structure.

GetColorInfoList

GetColorInfoList() returns any colors that match the specified pattern.

The format of the GetColorInfoList function is:

const ColorInfo **GetColorInfoList(const char *pattern,
  size_t *number_colors,ExceptionInfo *exception)

A description of each parameter follows:

pattern
Specifies a pointer to a text string containing a pattern.
number_colors
This integer returns the number of colors in the list.
exception
return any errors or warnings in this structure.

GetColorList

GetColorList() returns any colors that match the specified pattern.

The format of the GetColorList function is:

char **GetColorList(const char *pattern,size_t *number_colors,
  ExceptionInfo *exception)

A description of each parameter follows:

pattern
Specifies a pointer to a text string containing a pattern.
number_colors
This integer returns the number of colors in the list.
exception
return any errors or warnings in this structure.

ListColorInfo

ListColorInfo() lists color names to the specified file. Color names are a convenience. Rather than defining a color by its red, green, and blue intensities just use a color name such as white, blue, or yellow.

The format of the ListColorInfo method is:

MagickBooleanType ListColorInfo(FILE *file,ExceptionInfo *exception)

A description of each parameter follows.

file

List color names to this file handle.

exception

return any errors or warnings in this structure.

QueryColorname

QueryColorname() returns a named color for the given color intensity. If an exact match is not found, a hex value is returned instead. For example an intensity of rgb:(0,0,0) returns black whereas rgb:(223,223,223) returns #dfdfdf.

UPDATE: the 'image' argument is no longer needed as all information should have been preset using GetPixelInfo().

The format of the QueryColorname method is:

MagickBooleanType QueryColorname(const Image *image,
  const PixelInfo *color,const ComplianceType compliance,char *name,
  ExceptionInfo *exception)

A description of each parameter follows.

image

the image. (not used! - color gets settings from GetPixelInfo()

color

the color intensities.

Compliance

Adhere to this color standard: SVG, X11, or XPM.

name

Return the color name or hex value.

exception

return any errors or warnings in this structure.