PixelPacket Structure
The
PixelPacket
structure is used to represent pixels in ImageMagick. ImageMagick may be compiled to support 32 or 64 bit pixels. The size of PixelPacket is controlled by the value of the
QuantumDepth
define. The default is 64 bit pixels, which provide the best accuracy. If memory consumption must be minimized, or processing time must be minimized, then ImageMagick may be compiled with QuantumDepth=8. The following table shows the relationship between
QuantumDepth
, the type of
Quantum
, and the overall
PixelPacket
size.
Effect Of QuantumDepth Values
QuantumDepth
Quantum Type
PixelPacket Size
8
unsigned char
32 bits
16
unsigned short
64 bits
The members of the
PixelPacket
structure, and their interpretation, are shown in the following table:
PixelPacket Structure Members
Member
Type
Interpretation
Enumerations.html#ColorspaceType
RGBColorspace
Enumerations.html#ColorspaceType
RGBColorspace
+
Image.html#matte
matte
Enumerations.html#ColorspaceType
CMYKColorspace
red
Quantum
Red
Red
Cyan
green
Quantum
Green
Green
Magenta
blue
Quantum
Blue
Blue
Yellow
opacity
Quantum
Ignored
Opacity
Black
