how to extract R G B

I am working on palm print recognisation,I have an PALM image ,I need to extract R G B components and NRI,CAN ANYONE TELL HOW TO PROCESS,i HAVE UPLOADED THE IMAGE http://imgur.com/wNXiE

[Hitarth]

 im1=I(:,:,1);
 im2=rgb2gray(I);
 im3=imsubtract(im1,im2);
 imshow(im3)
 im4=im2bw(im3,0.5);
 imshow(im4)

Answer 1

[Image Analyst]

If you have an RGB image, to get the red, green, and blue:

% Extract the individual red, green, and blue color channels.
redChannel = rgbImage(:, :, 1);
greenChannel = rgbImage(:, :, 2);
blueChannel = rgbImage(:, :, 3);

If you have some special format image, such as a multi-page TIFF image, with the "N" image also stored in it (as your web page hints at), then you might look into the Tiff class. Look it up in the help, especially the page on "Reading Image Data and Metadata from TIFF Files"

[FIR]

thank u siR,could u please tell how to extraxt NIR PORTION for taht image which i have uploaded

http://imgur.com/wNXiE

[Walter Roberson]

That image is a PNG file. PNG files are not able to store additional bands, with the exception that a band could be encoded as the alpha (transparency) channel.

It is, however, not clear that what you uploaded was the _original_ image, so we could suspect that the original image was stored in some other file format.

Or is the question merely one of cropping that (already small) image to extract the portion labled NIR ? Working with images that small seems unlikely to be productive.

[Kwen]

This was exactly what I needed, thank you!!!