uniapp文件，如果是vue项目生命周期需要改一下
<template>
<div>
<canvas style="display: none" id="canvas"></canvas>
<div
id="extract-color-id"
class="extract-color"
style="display: flex;padding: 0 20px; justify-content:end;">
</div>
</div>
</template>
<script>
import colorExtraction from './colorExtraction.ts';
export default{
onLoad() {
const img = new Image();
img.src = `图片地址`;
img.crossOrigin = 'anonymous';
img.onload = () => {
colorExtraction.themeColor(1, img, 20, {x:22.058823529 , y:90.29411764} ,{width:22,height:22}, this.SetColor);
};
},
methods: {
SetColor(colorArr){
//返回的颜色判断是离黑白哪个近一些返回哪一个
// let newVal = colorExtraction.getClosestToWhiteOrBlack(colorArr);
// console.log(newVal);
//颜色取反
// let newColorArr = colorExtraction.reverse(colorArr)
// colorArr = newColorArr;
// 初始化删除多余子节点
const extractColor = document.querySelector('#extract-color-id');
while (extractColor.firstChild) {
extractColor.removeChild(extractColor.firstChild);
}
// 创建子节点
for (let index = 0; index < colorArr.length; index++) {
const bgc = '(' + colorArr[index][0] + ',' + colorArr[index][1] + ',' + colorArr[index][2] + ')';
const colorBlock = document.createElement('div');
colorBlock.id = `color-block-id${index}`;
colorBlock.style.cssText = 'height: 50px;width: 50px;margin-right: 10px;border-radius: 50%;';
colorBlock.style.backgroundColor = `rgb${bgc}`;
extractColor.appendChild(colorBlock);
}
}
},
}
</script>
colorExtraction.ts
/**
* 颜色盒子类
*
* @param {Array} colorRange [[rMin, rMax],[gMin, gMax], [bMin, bMax]] 颜色范围
* @param {any} total 像素总数, imageData / 4
* @param {any} data 像素数据集合
*/
class ColorBox {
colorRange: unknown[];
total: number;
data: Uint8ClampedArray;
volume: number;
rank: number;
constructor(colorRange: any[], total: number, data: Uint8ClampedArray) {
this.colorRange = colorRange;
this.total = total;
this.data = data;
this.volume = (colorRange[0][1] - colorRange[0][0]) * (colorRange[1][1] - colorRange[1][0]) * (colorRange[2][1] - colorRange[2][0]);
this.rank = total * this.volume;
}
getColor() {
const total = this.total;
const data = this.data;
let redCount = 0,
greenCount = 0,
blueCount = 0;
for (let i = 0; i < total; i++) {
redCount += data[i * 4];
greenCount += data[i * 4 + 1];
blueCount += data[i * 4 + 2];
}
return [redCount / total, greenCount / total, blueCount / total];
}
}
// 获取切割边
const getCutSide = (colorRange: number[][]) => { // r:0,g:1,b:2
const arr = [];
for (let i = 0; i < 3; i++) {
arr.push(colorRange[i][1] - colorRange[i][0]);
}
return arr.indexOf(Math.max(arr[0], arr[1], arr[2]));
}
// 切割颜色范围
const cutRange = (colorRange: number[][], colorSide: number, cutValue: any) => {
const arr1: number[][] = [];
const arr2: number[][] = [];
colorRange.forEach(function (item) {
arr1.push(item.slice());
arr2.push(item.slice());
})
arr1[colorSide][1] = cutValue;
arr2[colorSide][0] = cutValue;
return [arr1, arr2];
}
// 找到出现次数为中位数的颜色
const __quickSort = (arr: any[]): any => {
if (arr.length <= 1) {
return arr;
}
const pivotIndex = Math.floor(arr.length / 2);
const pivot = arr.splice(pivotIndex, 1)[0];
const left = [];
const right = [];
for (let i = 0; i < arr.length; i++) {
if (arr[i].count <= pivot.count) {
left.push(arr[i]);
}
else {
right.push(arr[i]);
}
}
return __quickSort(left).concat([pivot], __quickSort(right));
}
const getMedianColor = (colorCountMap: Record<string, number>, total: number) => {
const arr = [];
for (const key in colorCountMap) {
arr.push({
color: parseInt(key),
count: colorCountMap[key]
})
}
const sortArr = __quickSort(arr);
let medianCount = 0;
const medianIndex = Math.floor(sortArr.length / 2)
for (let i = 0; i <= medianIndex; i++) {
medianCount += sortArr[i].count;
}
return {
color: parseInt(sortArr[medianIndex].color),
count: medianCount
}
}
// 切割颜色盒子
const cutBox = (colorBox: { colorRange: number[][]; total: number; data: Uint8ClampedArray }) => {
const colorRange = colorBox.colorRange;
const cutSide = getCutSide(colorRange);
const colorCountMap: Record<string, number> = {};
const total = colorBox.total;
const data = colorBox.data;
// 统计出各个值的数量
for (let i = 0; i < total; i++) {
const color = data[i * 4 + cutSide];
if (colorCountMap[color]) {
colorCountMap[color] += 1;
}
else {
colorCountMap[color] = 1;
}
}
const medianColor = getMedianColor(colorCountMap, total);
const cutValue = medianColor.color;
const cutCount = medianColor.count;
const newRange = cutRange(colorRange, cutSide, cutValue);
const box1 = new ColorBox(newRange[0], cutCount, data.slice(0, cutCount * 4));
const box2 = new ColorBox(newRange[1], total - cutCount, data.slice(cutCount * 4));
return [box1, box2];
}
// 队列切割
const queueCut = (queue: any[], num: number) => {
while (queue.length < num) {
queue.sort((a: { rank: number }, b: { rank: number }) => {
return a.rank - b.rank
});
const colorBox = queue.pop();
const result = cutBox(colorBox);
queue = queue.concat(result);
}
return queue.slice(0, num)
}
// 颜色去重
const colorFilter = (colorArr: number[][], difference: number) => {
for (let i = 0; i < colorArr.length; i++) {
for (let j = i + 1; j < colorArr.length; j++) {
if (Math.abs(colorArr[i][0] - colorArr[j][0]) < difference && Math.abs(colorArr[i][1] - colorArr[j][1]) < difference && Math.abs(colorArr[i][2] - colorArr[j][2]) < difference) {
colorArr.splice(j, 1)
j--
}
}
}
return colorArr
}
//黑白判断
function getBrightness(r:any, g:any, b:any) {
return 0.299 * r + 0.587 * g + 0.114 * b;
}
function getClosestToWhiteOrBlack(colorArr: number[][]) {
let newArr:any = [];
let color:String="";
for (let index = 0; index < colorArr.length; index++) {
const element = colorArr[index];
const whiteBrightness = getBrightness(255, 255, 255);
const blackBrightness = getBrightness(0, 0, 0);
const currentBrightness = getBrightness(element[0], element[1], element[2]);
if (Math.abs(whiteBrightness - currentBrightness) < Math.abs(blackBrightness - currentBrightness)) {
color = 'White';
} else {
color = 'Black';
}
newArr.push(color);
}
return newArr;
}
//颜色取反
const reverse = (colorArr: number[][]) => {
let newArr:any = [];
for (let index = 0; index < colorArr.length; index++) {
const element = colorArr[index];
newArr[index] = [255-element[0],255-element[1],255-element[2]]
}
return newArr;
}
/**
* 提取颜色
* @param colorNumber 提取最大颜色数量
* @param img 需要提取的图片
* @param difference 图片颜色筛选精准度
* @param position 图片颜色的距离左上顶点位置百分比
* @param distance 图片颜色识别的宽高
* @param callback 回调函数
*/
const themeColor = (colorNumber: number, img: CanvasImageSource, difference: number, position:any = {x:0,y:0} ,distance:any={width:1,height:1},callback: (arg0: number[][]) => void) => {
const canvas = document.createElement('canvas') as HTMLCanvasElement;
const ctx = canvas.getContext('2d') as CanvasRenderingContext2D;
let width = 0
let height = 0
let imageData = null
canvas.width = img.width as number;
width = canvas.width as number
canvas.height = img.height as number
height = canvas.height
ctx.drawImage(img, 0, 0, width, height);
if(!distance){
distance = {
width:width,
height:height
}
}
imageData = ctx.getImageData(img.width as number * (position.x / 100), img.height as number * (position.y / 100), distance.width, distance.height).data;
const total = imageData.length / 4;
let rMin = 255,
rMax = 0,
gMin = 255,
gMax = 0,
bMin = 255,
bMax = 0;
// 获取范围
for (let i = 0; i < total; i++) {
const red = imageData[i * 4];
const green = imageData[i * 4 + 1];
const blue = imageData[i * 4 + 2];
if (red < rMin) {
rMin = red;
}
if (red > rMax) {
rMax = red;
}
if (green < gMin) {
gMin = green;
}
if (green > gMax) {
gMax = green;
}
if (blue < bMin) {
bMin = blue;
}
if (blue > bMax) {
bMax = blue;
}
}
const colorRange = [[rMin, rMax], [gMin, gMax], [bMin, bMax]];
const colorBox = new ColorBox(colorRange, total, imageData);
const colorBoxArr = queueCut([colorBox], colorNumber);
let colorArr = [];
for (let j = 0; j < colorBoxArr.length; j++) {
colorBoxArr[j].total && colorArr.push(colorBoxArr[j].getColor())
}
colorArr = colorFilter(colorArr, difference)
callback(colorArr);
}
export default {
themeColor,
reverse,
getClosestToWhiteOrBlack
}
