如何将base64字符串格式化图像转换为锐化图像缩减器期望的数据类型？

I'm trying to downsample an image in node. I have that image stored as a base64 encoded string (ie: "data:image/png;base64,iVBOR" etc.). I'm using Sharp npm package. The documentation appears to delineate that sharp can take either the filepath to an image or an "inputBuffer." I did some googling and assume the Buffer class is what they are referring to. Trying the code below among others continuously has resulted in me receiving the following error: "Input buffer contains unsupported image format." What could my issue be, and if you're not sure could you please recommend me a different npm package with more clear documentation?

我正在尝试对节点中的图像进行下采样。我将该图像存储为base64编码的字符串(即:“data:image / png; base64,iVBOR”等)。我正在使用Sharp npm包。该文档似乎描述了锐利可以将文件路径带到图像或“inputBuffer”。我做了一些谷歌搜索,并假设Buffer类是他们所指的。连续尝试下面的代码导致我收到以下错误:“输入缓冲区包含不受支持的图像格式。”我的问题可能是什么,如果你不确定,请你推荐一个不同的npm软件包和更清晰的文档?

 const downsizeProfileImgForTweet = (user, cb) => {
        let imgBuffer =  Buffer.from(user.profileImg, 'base64');
        sharp(imgBuffer)
        .resize(52, 52)
        .toBuffer()
        .then(data => {
            console.log("success");
            user.profileImg = data;
            cb()
        } )
        .catch( err => console.log(`downisze issue ${err}`) );
    }

I looked all over the internet and did a bunch of guess and checks, so forgive me for the noob question. Thanks in advance for any help you can offer!

我浏览了整个互联网,做了一堆猜测和检查,请原谅我的noob问题。预先感谢您提供的任何帮助!

2 个解决方案

#1

You need to remove the "data:image/png;base64" part.

您需要删除“data:image / png; base64”部分。

So here you are:

所以你在这里:

const uri = user.profileImg.split(';base64,').pop()
const downsizeProfileImgForTweet = (user, cb) => {
    let imgBuffer =  Buffer.from(uri, 'base64');
    sharp(imgBuffer)
    .resize(52, 52)
    .toBuffer()
    .then(data => {
        console.log("success");
        user.profileImg = data;
        cb()
    } )
    .catch( err => console.log(`downisze issue ${err}`) );
}

Not sure if it will work with the ".toBuffer() method, though it works like this for me (to write the file):

不确定它是否适用于“.toBuffer()方法,虽然它对我来说是这样的(写入文件):

sharp(imgBuffer)
    .resize(1920, null)
    .toFile(`${config.images_path}/${picture.filename}`)
    .then(data => {
        console.log('normal: ', data)
    })
    .catch(err => console.log(`downisze issue ${err}`))

I was struggling with this not so long ago…

不久前我正在努力解决这个问题......

#2

Try this?

const buf = new Buffer(img.replace(/^data:image/\w+;base64,/, ""),'base64')

const buf = new Buffer(img.replace(/ ^ data:image / \ w +; base64,/,“”),'base64')

#1