didder - 1.3.0-1+b1 main

didder is an extensive, fast, and accurate command-line image dithering
tool. It is designed to work well for both power users as well as
pipeline scripting. It is backed by the author's dithering library
(https://github.com/makew0rld/dither), and is unique in its correctness
and variety of dithering algorithms. It provides many options, while
being correct (linearizing the image, weighting channels by luminance).
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Types of dithering supported
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* Random noise (in grayscale and RGB)
* Ordered Dithering
* Bayer matrix of any size (as long as dimensions are powers of two)
* Clustered-dot - many different preprogrammed matrices
* Some unusual horizontal or vertical line matrices
* Yours? You can provide your own ordered dithering matrix in JSON format
* Error diffusion dithering
* Simple 2D
* Floyd-Steinberg, False Floyd-Steinberg
* Jarvis-Judice-Ninke
* Atkinson
* Stucki
* Burkes
* Sierra/Sierra3, Sierra2, Sierra2-4A/Sierra-Lite
* Steven Pigeon (https://hbfs.wordpress.com/2013/12/31/dithering/)
* Yours? You can provide your own error diffusion matrix in JSON format
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Features
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* Set palette using RGB tuples, hex codes, number 0-255 (grayscale), or
SVG color names (https://www.w3.org/TR/SVG11/types.html#ColorKeywords)
* Optionally recolor image with a different palette after dithering
* Set dithering strength
* Image is automatically converted to grayscale if palette is grayscale
* Force image to grayscale with --grayscale
* Change image saturation, brightness, or contrast before dithering
* Read EXIF rotation tags by default (disabled with --no-exif-rotation)
* Downscale image before dithering, keeping aspect ratio
* Upscale image after dithering, without producing artifacts
* Supports input image of types JPEG, GIF (static), PNG, BMP, TIFF
* Output to PNG or GIF
* Process multiple images with one command
* Combine multiple images into an animated GIF
* Uses all CPU cores when possible
* Support images with transparency (alpha channel is kept the same)