A memory-sparing PNG decoder for LVGL

This is a PNG image decoder for LVGL meant for systems with limited memory. It uses Pngle as a backend. It decodes in a streaming manner. As configured, it uses about 45kB of memory (~44k for Pngle and 1k buffer), plus the size of the buffer needed to store the image.

How to use

First of all, don't forget to download Pngle. Using git in lv_pngle folder:

git submodule update --init

Then, you need to include lv_pngle.h in your project and call lv_pngle_init() after initializing LVGL. That is:

#include "lv_pngle.h"

void main() {
  ...
  lv_init();
  lv_pngle_init();
  ...
}

Don't forget to compile and link lv_pngle.c, pngle.c and miniz.c as well. Also, you must deactivate the PNG decoder provided with LVGL, as it takes precedence.

Included is a CMake file for ESP-IDF, if you want to use it as a component for that platform.