title: Normalization of rgb images
body: <p>I am trying to remove the variation of illumination in two images. One of my approach is:</p>
  
  <pre><code>    1) There are two images im1 and im2. Extract the R G B content of im1.
      2)Calculate the normalized value for each content
      3)Reform a color image.
      4)Repeat the process for im2
      5)Compare each pixel and replace the content of im2 with im1.
  
  Image_rgb = imread('aswathy_33_crop.jpg');
  Image_rgb = double(Image_rgb);
  figure;imshow(uint8(Image_rgb));
  
  Image_red = Image_rgb(:,:,1);
  Image_green = Image_rgb(:,:,2);
  Image_blue = Image_rgb(:,:,3);
  
  
  [row,col] = size(Image_rgb(:,:,1));
  
  for y = 1:row 
  for x = 1:col 
     Red = Image_red(y,x);
     Green = Image_green(y,x);
     Blue = Image_blue(y,x);
  
  
      if(Red == 0 &amp;&amp; Green==0 &amp;&amp; Blue==0)
          Red = 1;
          Green = 1;
          Blue = 1;
      end
  
        NormalizedRed = Red/(Red + Green + Blue);
        NormalizedGreen = Green/(Red + Green + Blue);
        NormalizedBlue = Blue/(Red + Green + Blue);
  
   Image_red(y,x) = NormalizedRed;
   Image_green(y,x) = NormalizedGreen;
   Image_blue(y,x) = NormalizedBlue;
     end
  end
  Image_rgb(:,:,1) = Image_red;
  Image_rgb(:,:,2) = Image_green;
  Image_rgb(:,:,3) = Image_blue;
  
  new_image1 = cat(3, Image_rgb(:,:,1) ,Image_rgb(:,:,2), Image_rgb(:,:,3));
  
  figure; imshow(uint8(255*new_image1));
  </code></pre>
  
  <p>This is just normalization of single image, which at the end crashes with a completely distorted image.Can anyone suggest where I am going wrong and whether my approach to this issue is right or not?</p>
  
  <p><img src="https://i.stack.imgur.com/vLulK.jpg" alt="enter image description here"></p>
  
  <p>input1</p>
  
  <p><img src="https://i.stack.imgur.com/IhFOS.jpg" alt="enter image description here"></p>
  
  <p>input2</p>