I just posted Bitmap Creator/Converter for RETRO (with LCD_ST7735 library) on Codeshare. Feel free to discuss and make suggestions here.
Just posted an update that adds support for 16x16 bitmaps, in addition to the default 8x8.
Also added support for generating either named colors (per the colors in the Color565.h file in the LCD_ST7735 library) or uint16 values.
Also did some code cleanup, and renaming.
Comments and/or suggestions are welcome!
Looks good, I was going to suggest run-line-encoding - but for 16x16 and smaller it would probably be pointless.
That would probably make sense for anything larger than 16x16, but I’m not sure if @ taylorza’s library has any ability to decode such encoding. More likely, I’d need to add code for decoding. Wouldn’t necessarily be hard, but as you said, hard to justify the overhead for 8x8 or 16x16.
I don’t think the display is capable to work with run-line-encoding.