README
¶
Blind
Package blind implement color gradients
that are friendly for color blind people.
The color schemes are taken from Paul Tol page.
Here is a color gradient build by the gradient example based on rainbow color scheme (purple to red).
Implemented color schemes
Here are another gradients:
Full rainbow color scheme.
This scheme is not intended to be used in full,
rather use an slice frame
(such as the purple to red used by default in Gradient function).
Incandescent color scheme. This scheme is not printer friendly.
Authorship and license
Color schemes copyright © 2022 Paul Tol https://personal.sron.nl/~pault/ Code copyright © 2023 J. Salvador Arias jsalarias@gmail.com. All rights reserved. Distributed under BSD3 licenses that can be found in the LICENSE file.
Documentation
¶
Overview ¶
Package `blind` implement color gradients that are friendly for color blind people.
The color schemes are taken from Paul Tol page.
Example (Gradient) ¶
This example produces a gradient scale.
// Color schemes copyright © 2022 Paul Tol <https://personal.sron.nl/~pault/>
// Code copyright © 2023 J. Salvador Arias <jsalarias@gmail.com>.
// All rights reserved.
// Distributed under BSD3 licenses that can be found in the LICENSE file.
package main
import (
"fmt"
"image"
"image/color"
"image/png"
"os"
"github.com/js-arias/blind"
)
const size = 500
type gradient struct{}
func (g gradient) ColorModel() color.Model { return color.RGBAModel }
func (g gradient) Bounds() image.Rectangle { return image.Rect(0, 0, size, 100) }
func (g gradient) At(x, y int) color.Color {
v := float64(x) / (size - 1)
return blind.Gradient(v)
}
// This example produces a gradient scale.
func main() {
f, err := os.Create("gradient.png")
if err != nil {
panic(err)
}
defer func() {
if err := f.Close(); err != nil {
panic(err)
}
fmt.Printf("ok")
}()
if err := png.Encode(f, gradient{}); err != nil {
panic(err)
}
}
Output: ok
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
var ( // Incandescent color scheme: // https://personal.sron.nl/~pault/#fig:scheme_incandescent. // // This scheme is not print friendly. Incandescent = ColSeq{ {R: 206, G: 255, B: 255, A: 255}, {R: 198, G: 247, B: 214, A: 255}, {R: 162, G: 244, B: 155, A: 255}, {R: 187, G: 228, B: 83, A: 255}, {R: 213, G: 206, B: 4, A: 255}, {R: 231, G: 181, B: 3, A: 255}, {R: 241, G: 153, B: 3, A: 255}, {R: 246, G: 121, B: 11, A: 255}, {R: 249, G: 73, B: 2, A: 255}, {R: 228, G: 5, B: 21, A: 255}, {R: 168, G: 0, B: 3, A: 255}, } // Iridescent color scheme: // https://personal.sron.nl/~pault/#fig:scheme_iridescent. Iridescent = ColSeq{ {R: 254, G: 251, B: 233, A: 255}, {R: 252, G: 247, B: 213, A: 255}, {R: 245, G: 243, B: 193, A: 255}, {R: 234, G: 240, B: 181, A: 255}, {R: 221, G: 236, B: 191, A: 255}, {R: 208, G: 231, B: 202, A: 255}, {R: 194, G: 227, B: 210, A: 255}, {R: 181, G: 221, B: 216, A: 255}, {R: 168, G: 216, B: 220, A: 255}, {R: 155, G: 210, B: 225, A: 255}, {R: 141, G: 203, B: 228, A: 255}, {R: 129, G: 196, B: 231, A: 255}, {R: 123, G: 188, B: 231, A: 255}, {R: 126, G: 178, B: 228, A: 255}, {R: 136, G: 165, B: 221, A: 255}, {R: 147, G: 152, B: 210, A: 255}, {R: 155, G: 138, B: 196, A: 255}, {R: 157, G: 125, B: 178, A: 255}, {R: 154, G: 112, B: 158, A: 255}, {R: 144, G: 99, B: 136, A: 255}, {R: 128, G: 87, B: 112, A: 255}, {R: 104, G: 73, B: 87, A: 255}, {R: 70, G: 53, B: 58, A: 255}, } // Smooth rainbow scheme: // https://personal.sron.nl/~pault/#fig:scheme_rainbow_smooth. // // This scheme does not have to be used over the full range. Rainbow = ColSeq{ {R: 232, G: 236, B: 251, A: 255}, {R: 221, G: 216, B: 239, A: 255}, {R: 209, G: 193, B: 225, A: 255}, {R: 195, G: 168, B: 209, A: 255}, {R: 181, G: 143, B: 194, A: 255}, {R: 167, G: 120, B: 180, A: 255}, {R: 155, G: 98, B: 167, A: 255}, {R: 140, G: 78, B: 153, A: 255}, {R: 111, G: 76, B: 155, A: 255}, {R: 96, G: 89, B: 169, A: 255}, {R: 85, G: 104, B: 184, A: 255}, {R: 78, G: 121, B: 197, A: 255}, {R: 77, G: 138, B: 198, A: 255}, {R: 78, G: 150, B: 188, A: 255}, {R: 84, G: 158, B: 179, A: 255}, {R: 89, G: 165, B: 169, A: 255}, {R: 96, G: 171, B: 158, A: 255}, {R: 105, G: 177, B: 144, A: 255}, {R: 119, G: 183, B: 125, A: 255}, {R: 140, G: 188, B: 104, A: 255}, {R: 166, G: 190, B: 84, A: 255}, {R: 190, G: 188, B: 72, A: 255}, {R: 209, G: 181, B: 65, A: 255}, {R: 221, G: 170, B: 60, A: 255}, {R: 228, G: 156, B: 57, A: 255}, {R: 231, G: 140, B: 53, A: 255}, {R: 230, G: 121, B: 50, A: 255}, {R: 228, G: 99, B: 45, A: 255}, {R: 223, G: 72, B: 40, A: 255}, {R: 218, G: 34, B: 34, A: 255}, {R: 184, G: 34, B: 30, A: 255}, {R: 149, G: 33, B: 27, A: 255}, {R: 114, G: 30, B: 23, A: 255}, {R: 82, G: 26, B: 19, A: 255}, } // Smooth rainbow scheme from purple to red RainbowPurpleToRed = Rainbow[8:30] )
Sequential color schemes
Functions ¶
func Gradient ¶
Gradient returns a color gradient from low to high. The input value must be scaled from 0 to 1.
It is a continuous version of the Rainbow (purple to red) color scheme. Small values are in purple large values are in red.
Source Files