PNG libraries for Ruby

• ChunkyPNG is pure Ruby: no native dependencies, pixel access, text metadata. Slow for large images.
• ruby-vips binds libvips, which is fast and uses little memory. Used by Rails Active Storage for image variants.
• MiniMagick runs ImageMagick or GraphicsMagick commands. Simple, but starts a process for each operation.

• ChunkyPNG ChunkyPNG is a pure Ruby library to read and write PNG images. How to load and save PNG, set pixels, read text metadata, get the size without decoding.
• MiniMagick MiniMagick is a Ruby wrapper around the ImageMagick command line. How to resize and convert PNG files, set PNG compression, read image properties.
• ruby-vips ruby-vips is the Ruby binding of libvips, a fast, low-memory image library. How to read and write PNG files, make thumbnails, save palette PNGs.