nQuant is a .NET color quantizer producing high quality indexed PNG images using an algorithm optimized for the highest quality possible.
nQuant was originally developed as part of a larger effort called RequestReduce which is an HTTP module that automatically minifies and merges CSS as well as sprites their background images on the fly.
The original repository may be found here: https://nquant.codeplex.com/ This fork was forked from Philippecp's nQuantLeanerAndFaster fork.
This fork is based to Crazycat00's fork, which adds support to create 4-bit images, as the original only supports creating 8-bit images. The public interface is kept completely compatible with the original, so the same code will do the same thing.
In addition, OpenKH fork ditches support for .NET Framework prior to 4.6.1 version, by using .NET Standard 2.0 instead. This adds support for all the future releases of .NET Framework 4.6.1, .NET Core 2.0, Mono, Xamarin.
Usage is the same as the standard nQuant library, with the only exception being a new optional parameter on WuQuantizer.QuantizeImage. It's modified to:
Image QuantizeImage(Bitmap image, int alphaThreshold = 10, int alphaFader = 70, int maxColors = 256);- image: An image in 32-bit ARGB format.
- alphaThreshold: All colors with an alpha value equal to or less than this will be considered fully transparent.
- alphaFader: Alpha values will be normalized to the nearest multiple of this value.
- maxColors: The maximum number of colors in the output image format.
- 256: Return an 8-bit image containing 256 colors.
- 16: Return a 4-bit image containing 16 colors.
- 2: Return a 1-bit image containing 2 colors. (Note that the last color is transparent, so each pixel will either be fully transparent or not.)
See CHANGES.md for a list of major changes.
nQuant is issued under the Apache 2.0 license. See LICENSE.md for details.