无意中看到一篇文章写得是关于纯前端处理GIF图片的问题，感觉挺有意思的所以自己也实现了一下；
主要用到的有两个第三方库：合成GIF图片的gif.js和分解的libgif.js;
分解GIF
1. 引入Git库
import SuperGif from './libgif.js'
2. 处理图片
var file = e.target.files[0];
console.log(file.type.indexOf('image/gif'));
load_gif(file);
function load_gif(gif_source) {
var gifImg = document.getElementById('gifImg');
// gif库需要img标签配置下面两个属性
gifImg.setAttribute('rel:animated_src', URL.createObjectURL(gif_source))
gifImg.setAttribute('rel:auto_play', '0')
// 新建gif实例
var rub = new SuperGif({ gif: gifImg } );
var running = false;
rub.load(function(){
var img_list = [];
var j = 0;
console.log(rub.get_length());
for (var i=1; i <= rub.get_length(); i++) {
// 遍历gif实例的每一帧
rub.move_to(i);
var imgImage = new Image();
//canvas生成base64图片数据
imgImage.src = rub.get_canvas().toDataURL('image/jpeg',0.8);
}
}
合成GIF图片
1. 引入Git库
import GIF from './gif.js'
2. 图片合成
var gif = new GIF({
workers: 2,
quality: 10,
workerScript: 'js/gif.worker.js'
});
var j = 0;
var canvas= document.createElement("canvas");
var ctx = tCanvas.getContext('2d');
for (var i=1; i <= len; i++) {
var imgImage = new Image();
imgImage.src = img;
imgImage.onload = function (e) {
//Canvas绘制图片
canvas.width = width;
canvas.height = height;
console.log(width,height)
//铺底色
ctx.fillStyle = "#fff";
ctx.fillRect(0, 0, canvas.width, canvas.height);
ctx.drawImage(imgImage, 0, 0, width, height);
gif.addFrame(canvas,{copy:true,delay:50});
j++;
//图片
if(j>=len) {
gif.render()
};
}
}
gif.on('finished', function(blob) {
//生成图片链接
var url = URL.createObjectURL(blob);
}
