利用nodejs读取图片并将二进制数据转换成base64格式

fs.readFile('你的资源路径','binary',function(err,data){
    if(err){
        console.log(err)
    }else{
        console.log('数据读取成功');
    }
});

const buffer = new Buffer(data, 'binary');

buffer.toString('base64')

img.src = 'data: image/'+ getImageType(fileName) +';base64,' + buffer.toString('base64');
//获取当前图片的格式
function getImageType(str){
    var reg = /\.(png|jpg|gif|jpeg|webp)$/;
    return str.match(reg)[1];
}

fs.readFile('你的资源路径','binary',function(err,data){
    if(err){
        console.log(err)
    }else{
        const buffer = new Buffer(data, 'binary');
        img.src = 'data: image/'+ getImageType(fileName) +';base64,' + buffer.toString('base64');
    }
});

//保存图片
function saveImg(){
    const base64 = canvas.toDataURL().replace(/^data:image\/\w+;base64,/, ""); //必须去掉前缀
    const buffer = new Buffer(base64, 'base64');
    fs.writeFile('保存路径', buffer, function (err) {
        if(err) throw err;
        console.log('保存成功');
    });
}

const fs = require("fs");
const mineType = require("mime-types");
function imgToBase64(url) {
try {
let imgurl = config.imageUrl;
let imageData = fs.readFileSync(imgurl);
if (!imageData) return "";
let bufferData = Buffer.from(imageData).toString("base64");
let base64 = "data:" + mineType.lookup(imgurl) + ";base64," + bufferData;
return base64;
} catch (error) {
return "";
}
}