How to prepare graphics for eink displays
Intro Most of my blog posts share info about a general topic or highlight something interesting that I've discovered. This post will be essentially a tutorial or "how-to". Users of my display libraries probably know that they support Windows BMP files as a source of graphics. My latest eink libraries (both SPI and parallel - bb_epaper, FastEPD) both support this format in addition to a special lossless compression format I call Group5. It's challenging to describe in a few words what type of images will work correctly in both of these formats, so this article will walk through the steps needed to prepare graphics for eink projects. What's inside of the file? One of the first challenges of working with any image file format is that each file format can support quite a long list of different types of data within it. The two main variables are bit depth and compression options. Bit depth is probably the most confounding issue because it can be hidden in plain sight. ...