quantize

README

Quantize

🎨 Simple color palette quantization using MMCQ

Installing

You can fetch this library by running the following

go get -u github.com/joshdk/quantize

Usage

import (
	"image/color"
	"image/jpeg"
	"net/http"
	"github.com/joshdk/preview"
	"github.com/joshdk/quantize"
)

// Fetch the source image
resp, err := http.Get("https://blog.golang.org/gopher/plush.jpg")
if err != nil {
	panic(err.Error())
}

// Decode jpeg contents
img, err := jpeg.Decode(resp.Body)
if err != nil {
	panic(err.Error())
}

// Reduce image into a palette of 8 colors
colors := quantize.Image(img, 3)

palette := make([]color.Color, len(colors))
for index, clr := range colors {
	palette[index] = clr
}

// Display our new palette
preview.Show(palette)

As an example, we can reduce a photo of the Go Gopher (source) into a color palette.

License

This library is distributed under the MIT License, see LICENSE.txt for more information.

Documentation

Index

• func Average(pixels []color.RGBA) color.RGBA
• func Image(img image.Image, levels int) []color.RGBA
• func Partition(pixels []color.RGBA) ([]color.RGBA, []color.RGBA)
• func Pixels(pixels []color.RGBA, levels int) []color.RGBA
• func Spread(pixels []color.RGBA) (uint8, uint8, uint8)

Functions

func Average

func Average(pixels []color.RGBA) color.RGBA

Average takes in a slice of RGB pixels, and returns the average across the red, green, & blue components of all pixels.

func Image

func Image(img image.Image, levels int) []color.RGBA

Image is a helper that converts the given image into a slice of RGB pixels before performing MMCQ.

func Partition

func Partition(pixels []color.RGBA) ([]color.RGBA, []color.RGBA)

Partition takes in a slice of RGB pixels, and bisects the slice with respect to the color component with the largest spread.

func Pixels

func Pixels(pixels []color.RGBA, levels int) []color.RGBA

Pixels takes in a slice of RGB pixels, and performs the MMCQ process to the specified number of levels. Returns a slice of RGB colors of length 2^levels.

func Spread

func Spread(pixels []color.RGBA) (uint8, uint8, uint8)

Spread takes in a slice of RGB pixels, and returns the delta across the red, green, & blue components of all pixels.