[Saturation] Saturate or Desaturate an image in Matlab

function rgb_result=saturate(rgb,factor)

%Saturates of Desaturates an image

%   J=saturate(I,factor) returns an image J that is factor times the

%   saturation of 8bit color image I. So 0 is no saturation, 2 is double

%   andsoforth. You get the idea. Otherwise visit me at: www.timzaman.nl

%

%   Examples

%   --------

%   Removes all saturation

%

%       I = imread('rice.png');

%       J = saturate(I,0);

%       figure, imshow(I), figure, imshow(J)

%

%   Doubles the saturation

%

%       I = imread('rice.png');

%       J = saturate(I,2);

%       figure, imshow(I), figure, imshow(J)

%

%

%   Note

%   ----

%   This is the first version without much support

%

%   Class Support

%   -------------

%   The input image rgb should be 8bit unsigned

%

%   See also makecform, applycform

%   Written by Tim Zaman, TU Delft, 2011

%   This work, unless otherwise expressly stated, is licensed under a

%   Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.

%   Obviously provided "AS-IS"

rgblab=makecform('srgb2lab');

labrgb=makecform('lab2srgb');

lab = applycform(rgb,rgblab);

lab=int16(lab);

lab=lab-128;

lab(:,:,2)=lab(:,:,2)*factor;

lab(:,:,3)=lab(:,:,3)*factor;

lab=uint8(lab+128);

rgb_result = applycform(lab,labrgb);

end