Problem
Think about how the gray scale algorithm works. Basically, if you know the luminance of anything visual (e.g., a small image, a letter), you can replace a pixel with that visual element in a similar way to create a collage image. Try implementing this. You'll need 256 visual elements of increasing lightness, all of the same size. You can create a collage by replacing each pixel in the original image with one of these visual elements.