png_conform

https://github.com/claricle/png_conform

PngConform provides a comprehensive PNG, MNG, and JNG file validation library in pure Ruby. It validates file structure, chunk validity, CRC checksums, zlib compression, and profile conformance. Built with a layered architecture using BinData for binary parsing, Lutaml::Model for domain models, and Thor for CLI. Supports PNG baseline, MNG-VLC, MNG-LC, and JNG profiles with detailed validation reporting compatible with pngcheck output.