ImageMagick PixelPacket Structure
The PixelPacket structure is used to represent DirectClass
color pixels in ImageMagick. If the image
is indicated as a PseudoClass
image, its DirectClass representation is only valid immediately after calling
SyncImage(). If an image is set as PseudoClass and the DirectClass representation
is modified, the image should then be set as DirectClass. Use QuantizeImage()
to restore the PseudoClass colormap if the DirectClass representation is
modified.
The members of the PixelPacket structure are shown in the following
table:
PixelPacket Structure Members
|
Member
|
Type
|
Interpretation
|
|
RGBColorspace (3)
|
RGBColorspace +
matte(3)
|
CMYKColorspace
|
| red |
Quantum |
Red |
Red |
Cyan |
| green |
Quantum |
Green |
Green |
Magenta |
| blue |
Quantum |
Blue |
Blue |
Yellow |
| opacity |
Quantum |
Ignored |
Opacity |
Black |
Notes:
-
Quantum is an unsigned short (MaxRGB=65535) if ImageMagick is built using
-DQuantumDepth=16 Otherwise it is an unsigned char (MaxRGB=255).
-
SyncImage() may be used to synchronize the DirectClass color pixels to
the current PseudoClass colormap.
-
For pixel representation purposes, all colorspaces are treated like RGBColorspace
except for CMYKColorspace.
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