added read-pixel method
added read-pixel method

walterbender/turtleconfusion,AlanJAS/turtleart,walterbender/turtle3D,walterbender/AmazonasTortuga,walterbender/turtleflags,walterbender/turtleart,walterbender/turtleartmini,max630/turtleart-hacks,max630/turtleart-hacks