heif  3.7.0
About: HEIF (High Efficiency Image File Format) is a visual media container format for images and image sequences (MPEG-standard). This HEIF engine demonstrates its powerful features and capabilities (under Nokia HEIF license).
  Fossies Dox: heif-3.7.0.tar.gz  ("unofficial" and yet experimental doxygen-generated source code documentation)  
High Efficiency Image File Format Implementation APIs:

Android Java/JNI API that combines both reader and writer operations see com.nokia.heif.HEIF class.
It internally relies on native c++ API below:

C++ Object based API that combines both reader and writer operations see HEIFPP::Heif class.
It internally wraps APIs below:

C++ HEIF writing API see HEIF::Writer class.

C++ HEIF reading API see HEIF::Reader class.