I attempted to draw a mono bitmap from the single example on your website. As it stands, the C file is attempting to store the data in SRAM. A Uno does not have enough SRAM.
I'm not using RAM to store const data. ARM GCC places it in a TEXT section at program memory flash.
It is rather a question to AVR compiler and its differences from the ARM.
There does not seem to be any way to load a JPG, PNG, BMP, ... from my PC and convert to the C array.
I can convert any image to raw data for display controller's format. This eliminates the need for using jpg/png.
Also I can store binary file at file system or directly embed file to firmware with other tools of gcc.
So... Saving jpg, png and other files in the C array is not at all an important task to consider. This is also not the best way to solve this problem.
There are online programs e.g
It's great that you have enough of this limited tool.
So what about increasing the size of the firmware when duplicating data from the header files? Is this problem present in Arduino/AVR like the ARM GCC? Or completely solved by the developers of the compiler?