Js 从 web 获取图像并用 base64编码

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最佳答案

BufferList is obsolete, as its functionality is now in Node core. The only tricky part here is setting request not to use any encoding:

var request = require('request').defaults({ encoding: null });


request.get('http://tinypng.org/images/example-shrunk-8cadd4c7.png', function (error, response, body) {
if (!error && response.statusCode == 200) {
data = "data:" + response.headers["content-type"] + ";base64," + Buffer.from(body).toString('base64');
console.log(data);
}
});

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You can use the base64-stream Node.js module, which is a streaming Base64 encoder / decoder. The benefit of this method is that you can convert the image without having to buffer the whole thing into memory, and without using the request module.

var http = require('http');
var base64encode = require('base64-stream').Encode;


http.get('http://tinypng.org/images/example-shrunk-8cadd4c7.png', function(res) {
if (res.statusCode === 200)
res.pipe(base64encode()).pipe(process.stdout);
});

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I use for load and encode image into base64 string node-base64-image npm module.

Download and encode an image:

var base64 = require('node-base64-image');


var options = {string: true};
base64.base64encoder('www.someurl.com/image.jpg', options, function (err, image) {
if (err) {
console.log(err);
}
console.log(image);
});

Encode a local image:

var base64 = require('node-base64-image');


var path = __dirname + '/../test.jpg',
options = {localFile: true, string: true};
base64.base64encoder(path, options, function (err, image) {
if (err) { console.log(err); }
console.log(image);
});

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LATEST, AS OF 2017 ENDING

Well, after reading above answers and a bit research, I got to know a new way which doesn't require any package installation, http module(which is built-in) is enough!

NOTE: I have used it in node version 6.x, so I guess its also applicable to above versions.

var http = require('http');


http.get('http://tinypng.org/images/example-shrunk-8cadd4c7.png', (resp) => {
resp.setEncoding('base64');
body = "data:" + resp.headers["content-type"] + ";base64,";
resp.on('data', (data) => { body += data});
resp.on('end', () => {
console.log(body);
//return res.json({result: body, status: 'success'});
});
}).on('error', (e) => {
console.log(`Got error: ${e.message}`);
});

I hope it helps!

Also, check more about the http.get(...) here !

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If you know the image type, it's a one-liner with the node-fetch package. Might not suit everyone, but I already had node-fetch as a dependency, so in case others are in a similar boat:

await fetch(url).then(r => r.buffer()).then(buf => `data:image/${type};base64,`+buf.toString('base64'));

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If anyone encounter the same issue while using axios as the http client, the solution is to add the responseType property to the request options with the value of 'arraybuffer':

let image = await axios.get('http://aaa.bbb/image.png', {responseType: 'arraybuffer'});
let returnedB64 = Buffer.from(image.data).toString('base64');

Hope this helps

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If you are using axios then you can follow below steps

var axios = require('axios');
const url ="put your url here";
const image = await axios.get(url, {responseType: 'arraybuffer'});
const raw = Buffer.from(image.data).toString('base64');
const base64Image = "data:" + image.headers["content-type"] + ";base64,"+raw;

you can check with decode base64.

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Another way of using node fetch, which breaks down the steps per variable:

const fetch = require('node-fetch');


const imageUrl = "Your URL here";
const imageUrlData = await fetch(imageUrl);
const buffer = await imageUrlData.arrayBuffer();
const stringifiedBuffer = Buffer.from(buffer).toString('base64');
const contentType = imageUrlData.headers.get('content-type');
const imageBas64 =
`data:image/${contentType};base64,${stringifiedBuffer}`;

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Oneliner:

Buffer.from(
(
await axios.get(image, {
responseType: "arraybuffer",
})
).data,
"utf-8"
).toString("base64")

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Old post but could help someone. On the basis of Dmytro response that help me.

const base64FromUrl = async (url: string) => {
try {
return Buffer.from((await axios.get(url, { responseType: "arraybuffer", })).data, "utf-8").toString("base64")
} catch (error) {
return ""
}
}

I've just add error handling.

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You can use image-to-base64 Node.js module

The benefit of using this module is that you convert your image hassle-free

const imageToBase64 = require('image-to-base64');


const imageLink = 'Your image link'
imageToBase64(imageLink);
.then((response) => {
const base64Image = `data:image/png;base64,${response}`
console.log(base64Image);
})
.catch((error) => {
console.log(error);
})