For a pet project of mine (yet unpublished) I needed a library which is able to gather metadata from image files (dimensions, animation info, color info, etc.). I searched for one and the only closest thing I managed to find was rexiv2, which is based on gexiv2, which has a somewhat complex API and is overly generic for my purposes (e.g. it seems that it does not allow to inspect image type-specific metadata).
And so I decided to write a pure-Rust image metadata gathering library. At the moment it is able to parse JPEG, GIF and PNG files but I’ll add new formats in future and will probably extend existing formats, like adding EXIF support for JPEG files.