Histogram of color image

I hide message inside image using LSB .It is work but I get a different style of output of histogram.how to solve it?

my code is:

subplot(4, 4, 2); 

      Red = coverimage(:,:,1);
      Green = coverimage(:,:,2);
      Blue = coverimage(:,:,3);

      %Get histValues for each channel
      [yRed, x] = imhist(Red);
      [yGreen, x] = imhist(Green);
      [yBlue, x] = imhist(Blue);

      %Plot them together in one plot
      plot(x, yRed, 'Red', x, yGreen, 'Green', x, yBlue, 'Blue');
      title('Histogram of Cover image ', 'FontSize', fontSize);             

subplot(4, 4, 4); 

      Red = stegoimage(:,:,1);
      Green = stegoimage(:,:,2);
      Blue = stegoimage(:,:,3);
      [yRed1, x1] = imhist(Red);
      [yGreen1, x1] = imhist(Green);
      [yBlue1, x1] = imhist(Blue);
      plot(x1, yRed1, 'Red', x1, yGreen1, 'Green', x1, yBlue1, 'Blue');
        title('Histogram of Stego image ', 'FontSize', fontSize);

Answer 1

[muratcan tek]

I fixed it

coverimage=imread('image.jpg');
  Red = coverimage(:,:,1);
  Green = coverimage(:,:,2);
  Blue = coverimage(:,:,3);
       [yRed, x] = imhist(Red);
       [yGreen, x] = imhist(Green);
       [yBlue, x] = imhist(Blue);
   subplot(1, 2, 1); 
    
         plot(x, yRed, 'Red', x, yGreen, 'Green', x, yBlue, 'Blue');
         title('Histogram of Cover image ', 'FontSize', 1);             
   subplot(1, 2, 2); 
         bar(yRed, 'Red') ,hold on , bar(yGreen, 'Green'), hold on ,bar( yBlue, 'Blue');
         title('Histogram of Stego image ', 'FontSize', 1);

Answer 2

[muratcan tek]

this is better

coverimage=imread('image.jpg');
  Red = coverimage(:,:,1);
  Green = coverimage(:,:,2);
  Blue = coverimage(:,:,3);
       [yRed, x] = imhist(Red);
       [yGreen, x] = imhist(Green);
       [yBlue, x] = imhist(Blue);
   subplot(1, 2, 1); 
    
         plot(x, yRed, 'Red', x, yGreen, 'Green', x, yBlue, 'Blue');
         title('Histogram of Cover image ', 'FontSize', 1);             
   subplot(1, 2, 2); 
         bar(yRed, 'Red') ,hold on , bar(yGreen, 'Green'), hold on ,bar( yBlue, 'Blue');
         title('Histogram of Stego image ', 'FontSize', 1);

Answer 3

[Image Analyst]

It's because your cover image has a continuous histogram - counts for every gray level - while your stego image does not. The stego image has no counts for some gray levels. It looks like it contains only even or only odd gray levels, probably as an artifact of your encoding process.