If you want to do a simple test, you can just generate some images with ImageMagick: $ convert -size 512x512 canvas:red canvas_red.jpg $ convert -size 512x

If you want to do a simple test, you can just generate some images with ImageMagick: $ convert -size 512x512 canvas:red canvas_red.jpg $ convert -size 512x512 canvas:blue canvas_blue.jpg