I don't know about other graphics libs like tinyptc or whatever, however if you are using FB's internal fbgfx graphics library and have the image loaded into an FB.Image ptr, you can use "Point (x, y), img" to get the color attribute for each pixel in the image, and then "PSet img, (x,y), color" to rebuild the image from data. One thing to remember though is that the results will vary depending on what bit depth you have the screen set to.