colormix

ColorMix - A Go Library for Color Mixing Optimization

ColorMix is a Go library that optimizes color mixing by adjusting the proportions of a given set of colors to match a target color. The library uses optimization algorithms to find the best weights (proportions) for a set of colors in order to minimize the difference between the mixed color and the target color. The optimization is based on color differences, and it supports advanced optimization techniques.

Features

• Mix colors to match a target color.
• Uses CIEDE2000 color difference metric for better perceptual accuracy.
• Supports different optimization algorithms like Nelder-Mead for general use cases.
• Prevents zero color contributions through penalty functions.

Installation

To install the ColorMix library, use the go get command:

go get -u github.com/bububa/colormix

Example Usage

Import the package

import "github.com/yourusername/colormix"

Basic Example: Mix Colors to Match a Target

Here is a simple example of how to use the library to mix a set of colors and match a target color.

package main

import (
	"fmt"
	"image/color"

	"github.com/bububa/colormix"
)

func main() {
	targetColor := color.RGBA{200, 100, 50, 255}
	palette := colormix.NewPalette(
		// RED
		color.RGBA{255, 0, 0, 255},
		// GREEN
		color.RGBA{0, 255, 0, 255},
		// BLUE
		color.RGBA{0, 0, 255, 255},
		// WHITE
		color.RGBA{255, 255, 255, 255},
		// BLACK
		color.RGBA{0, 0, 0, 255},
	)
	mixedColor, err := colormix.Mix(targetColor, palette, RGB)
	if err != nil {
		return
	}
	fmt.Printf("Target: %s\n", MakeColor(targetColor).Hex())
	fmt.Println("")
	for _, v := range palette.Colors() {
		fmt.Printf("%s: %.0f%%\n", v.Hex(), v.Ratio()*100)
	}
	fmt.Println("")
	fmt.Printf("Mixed: %s\n", MakeColor(mixedColor).Hex())
	// Output:
	// Target: #c86432
	//
	// #ff0000: 56%
	// #00ff00: 11%
	// #0000ff: 1%
	// #ffffff: 2%
	// #000000: 30%
	//
	// Mixed: #c86432
}

Explanation

1. palette: This is a matrix containing the available colors in RGB format.
2. targetColor: The target color that we want to match through mixing.
3. Mix: This function finds the optimal proportions (weights) of the available colors that best approximate the target color.
4. mixedColor: Once the optimal weights are calculated, this function computes the resulting mixed color based on the color table and the calculated weights.

Color Metrics

The library uses the CIEDE2000 color difference metric to calculate the color differences, which provides a more perceptually accurate measure of color difference than Euclidean distance in RGB space.

Available Functions

MixColors(targetColor color.Color, palette *colormix.Palette, colorspace colormix.ColorMix) (mixedColor color.Color, err error): Computes the optimal weights for the given color table to match the target color and Calculates the final mixed color based on the optimal weights and the color table.

Optimizers Supported

• Nelder-Mead: A simplex-based optimization method that doesn't require derivatives. Suitable for non-differentiable functions.
• LBFGS (Limited-memory Broyden–Fletcher–Goldfarb–Shanno): A gradient-based method that is more efficient for smooth, differentiable functions.

Contributing

We welcome contributions! If you find a bug or want to suggest a feature, feel free to open an issue or submit a pull request.

Steps to Contribute:

1. Fork the repository.
2. Create a new branch (git checkout -b feature-name).
3. Make your changes and commit them (git commit -am 'Add new feature').
4. Push to the branch (git push origin feature-name).
5. Open a pull request.

License

This project is licensed under the MIT License—see the LICENSE file for details.