– If it helps, the JS file is optimized using an improved version of Google Closure Compiler (with no line break, better float formatting, etc).
– File byte order is reversed or not (depending on whether it improves final compression rate or not).
– It embeds the resulting file in a PNG image, choosing the best PNG format (RGB or gray).
– Then it uses the most efficient PNG optimizer tool (PNGOUT or another one).
– The output PNG is stripped of CRC and IEND block.
– Finally a loader is appended to the output file. In the loader, V is the name of canvas element and C is the name of its 2D context. By reusing this variables in your JS code, you have an access to an existing canvas element and its 2D context and do not have to create new ones (it saves a few bytes).