Sometime last night, I posted a Repl that made the funny Zwack image. It was horribly inefficient, and it took up a lot of space. This is that engine, but way more optimized. Instead of an array, it uses one single string to store all of the hex values consecutively. This allows me to change the data on-the-fly without having to replace all the code.
To use this program, insert the image data into the console and hit Enter. To get this data from a pre-existing image file, fork this Repl and change the code to generate the right files.
Some sample image data (they are really big):