title: Turn black pixel on the first image to white if it is also black on a second co-located image
body: <p>I have 2 co-located images, both created in a similar way and both have the size of 7,221 x 119 pixels. </p>
  
  <p>I want to write a logic like this: </p>
  
  <p>If the R,G,B values of a certain pixel (called it x) in image 1 = 0,0,0 (black) And the R,G,B values of pixel x in image 2 = 0,0,0 (black) then change the R,G,B values of pixel x in image 1 to 255,255,255 (white), Else no change.</p>
  
  <p>How can I do this in either Matlab or Python?</p>