Question

在我的node.js项目中，我希望能够从网络中提取图像，将其大小调整为我想要的大小，并输出为base64字符串。

哪个库是最好的方法？我尝试了很多不同的但没有一个正在工作：

var url = "www.abc.com/image.png"

var gm = require('gm')

gm(request(url))
.resize(100, 100)
.setFormat('jpg')
.toBuffer(function (err, buffer) {
  if (err) {
    console.log("error" + err);
  } else {
    console.log('done!');
  }
})

var Canvas = require('canvas')
  , Image = Canvas.Image
  , canvas = new Canvas(200, 200)
  , ctx = canvas.getContext('2d');

// set its dimension to target size
canvas.width = width;
canvas.height = height;

// draw source image into the off-screen canvas:
ctx.drawImage(request(url), 0, 0, width, height);

console.log(canvas.toDataURL());

sharp('input.gif')
  .resize(478, 269)
  .toFormat('jpeg')
  .toBuffer(function(err, outputBuffer) {
    if (err) {
      throw err;
    }
    // outputBuffer contains WebP image data of a 200 pixels wide and 300 pixels high
    // containing a scaled version, embedded on a transparent canvas, of input.gif
});



require('lwip').open(request(url), function(err, image){
    image.resize(300, 200, function(err, image){
        console.log("done");
    });
});


var request = require('request');
var lwip    = require('lwip');
request({url: url, encoding:null}, function (err, response, imageBuffer) {
    var imageFormat = response.headers["content-type"].match(/(png|jpg|jpeg)/)[0];  
        lwip.open( imageBuffer, imageFormat, function(err, image){
            if (err || !image) throw err;
            image.resize(196, 196, function(err, image){
                if (err || !image) throw err;
                image.toBuffer(imageFormat, function(err, buffer){
                     //here you buffer you can save image in file with FS
                });
            });
        });
    }
});

Answer 1

这是一种有点不同的方法这是咖啡脚本，因此您需要将其更改为普通的javascript 首先从服务器下载图像然后按如下方式调整图像大小

gm downloadedFile.path
  .resize 100, 100
   # thumbpath is resized file storage path
   .write thumbpath, (err) =>
     if err
      console.log err
     #convert as base64
     bitmap = fs.readFileSync(thumbpath)
     base64 = new Buffer(bitmap).toString('base64')

调整服务器大小的图像大小

1 个答案: