can any one tell me how to extract only the l component of the image ..if the image is rgb ..i want only the l component of the image ,how is it possible

can any one tell me how to extract only the l component of the image ..if the image is rgb ..i want only the l component of the image ,how is it possible

Answer 1

[Dishant Arora]

R=YourImage(:,:,1);
G=YourImage(:,:,2);
B=YourImage(:,:,3);

[Thomas Seers]

beat me to it!

[ashok]

i asked how to extract only the l component from the image not r ,g,b seperately

[Thomas Seers]

You mean intensity? It looks like a 1!

[Thomas Seers]

If so convert to grayscale:

 gray = rgb2gray(im); % with image processing toolbox
 GIm=0.2989*im(:,:,1)+0.5870*im(:,:,2)+0.1140*im(:,:,3); % without

There are other methods posted here: http://www.johndcook.com/blog/2009/08/24/algorithms-convert-color-grayscale/

[Dishant Arora]

you need intensity component?? To get the intensity notion you can take mean of the three components as it happens in HSI model:

I=1/3*(R+G+B);

also you can follow YCbCr model to get intensity:

Y = 0.2126*R + 0.7152*G + 0.0722*B

where Y denotes luminosity.

Answer 2

[Thomas Seers]

Lets say you have a three channel RGB image, im.

% extract the red channel

 red = im(:,:,1);

% extract the green channel

 green = im(:,:,2);

% extract the blue channel

 blue = im(:,:,3);

Simples!

[ashok]

i asked how to extract only the l component from the image not r ,g,b seperately