CImage:ExtractChan

The ExtractChan method creates a new image containing a channel from the original color image.

Syntax

CImage = CImage:ExtractChan( nChan )

where

nChan is the channel name, like "R", "G", "B", or "A", or a corresponding number beginning at 1.

CImage is a new CImage object containing the extracted channel.

On success, this method returns a new CImage.

On failure, this method return nil.

Example

Suppose that a CImage I exists and has RGB color data type. The following script creates 3 new images, one each for the red, green, and blue channels (channels 1 through 3):

S = CImageSet:new()	-- create an image set to hold the images
for i=1, 3 do	-- do for each of the 3 channels
Inew = I:ExtractChan(i)	-- extract the channel to a new CImage
S:Append( Inew )	-- add to the end of the image set
end
I = S:GetImage(2)	-- retrieve the green image...