Topic "rgb"

RGB			   Monash Image Library				RGB


Most image library routines have been written for single band 8 bpp images,
although some will also work with 16, 32 and even 64 bpp images. To apply
these routines to 3-band images the image must be split into its three
bands.

When programming in C, this can be achieved using the routines i_rgbsplit(), 
i_rgbextract and i_rgbmerge().

When using the Unix shell, the -b flag may be specified to indicate that
this is a three band image, and that you want to apply a single band routine
to each band of the 3-band image.

eg.
-b1 indicates that the routine should be applied to only the first band,
-b23 indicates that the routine should be applied to the second and third
-bands, and -ba will apply the routine to all three bands.

Note that a 3-band image is usually the result when using these flags, and
that there are some routines where this will result in an error if the
resulting images cannot be merged (eg: ihalf on one band only).

Pixel manipulation with three band images is more difficult as the pixel in
each band much modified individually. i_getrgb and i_putrgb may can be used
if all three values are to be modified at once.

Note: All these functions do not check or use the colour space information
of an image.
 

Related Functions

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