No os.exec call of pngquant or mozjpeg. Only bindings to libraries.
Using libvips for fast image resizing
Docker container uses libvips compiled with mozjpeg instead of libjpeg-turbo. MozJPEG makes tradeoffs that are intended to benefit Web use cases and focuses solely on improving encoding, so it's best used as part of a Web encoding workflow.
png images are optimized with libimagequant (backend library of pngquant)
Get resized to 500x500 version converted to webp (image will be resized and striped to 500x500 and converted to webp) http://example.com/img/test.jpg@500x500?fmt=webp. Supported formats: jpeg (or jpg), png, webp, tiff.
Get resized to 500x500 version with custom compression (image will be resized and striped to 500x500) http://example.com/img/test.jpg@500x500?cmp=9. Compression value range: from 0 to 9.