title: Access RGB channels in an image in MATLAB
body: <p>I want to access the red channel of each pixel in my image. I don't want to change it. I just want to identify the pixels with a range of red. I'm looking for pixels that will have the colors like RGB(15,0,0), RGB(120,0,0), RGB(200,0,0) and so on. My image is mostly gray, I want to identify the red boxes on that.</p>
  
  <p>I tried:</p>
  
  <pre><code>image = imread('myimage.jpg');
  figure; imshow(image);
  
  redPlane = image(:,:,1);
  figure; imshow(redPlane);
  </code></pre>
  
  <p>The second figure displayed is all gray. It took off the red.</p>