Quanto is a PNG-quantization tool strongly inspired by ImageAlpha. It uses the same existing algorithms: PngQuant, Posterizer and pngnq to transform any PNG into a 8-bit palettized image. This is an efficient way of generating a smaller image file while preserving perceptual quality. Please see the LICENSE_EXTERNAL.md file for the libraries respective licenses.

Both a command line tool and a GUI application are provided.

• Three quantization algorithms.
• Custom number of colors in the palette.
• Support for dithering.
• Support for removing the alpha channel of an image.
• Compare the size of your image before and after.
• Zoom and pan the generated image, compare it with the source.
• Drag and drop an image to process it.

• --i,--in <path(s) to file(s)>
  Image(s) to quantize
• --o,--out <path(s) to file(s)>
  Destination path(s). If empty, will use input path + timestamp or the input path itself if --force enabled
• --f,--force
  Output in place if no output path specified, erasing input file(s) if present (disabled by default)

• --m,--mode <(0: ImageQuant, 1: PngNeuQuant, 2: Posterizer)>
  Compressor to use (defaults to ImageQuant)
• --c,--colors <in 2,256>
  Number of colors in the palette (defaults to 256)
• --d,--dither
  Should dithering be applied (disabled by default)
• --na,--no-alpha
  Remove alpha channel (disabled by default)

• --v,--version
  Displays the current Thoth version.
• --license
  Display the license message.
• --license-ext
  Display the dependencies license messages.

• Improve zooming (filtering mode,...).
• Add support for pngcrush.