zxing_ffi

https://github.com/withniva/zxing_ffi

Extracts barcodes (QR and every symbology zxing-cpp can read) from PNG, JPEG, TIFF, GIF, BMP, WebP, HEIF, PNM and PDF inputs in any orientation. Binds the zxing-cpp C API with the ffi gem and adds a pipeline around it: input sniffing, normalization to 8-bit grayscale, an escalating sequence of decode passes, coordinate mapping, deduplication and filtering.