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Third-party licenses

The image viewer links the following third-party libraries. Their licenses are permissive and allow redistribution, including in the firmware binary.

Baseline and progressive JPEG decoding use the Independent JPEG Group’s libjpeg (version 9f), vendored under components/libjpeg/. This software is based in part on the work of the Independent JPEG Group. The full IJG license is in components/libjpeg/README (“LEGAL ISSUES”); it permits use for any purpose provided that README is distributed with the source.

Project additions, kept separate from the pristine upstream sources:

  • jconfig.h - build configuration for the ESP toolchain.
  • jmem_psram.c - the system-dependent memory manager, allocating from PSRAM (replaces the upstream jmemnobs.c, which is left unmodified).
  • CMakeLists.txt - ESP-IDF component build.

PNG decoding uses espressif/libpng (libpng 1.6), pulled by the ESP component manager. Distributed under the PNG Reference Library License (libpng license).

PNG inflate uses espressif/zlib, a dependency of libpng. Distributed under the zlib license.