Question

我需要更新上传图片的方向标记（EXIF数据）。我正在使用＆＃34; PIEXIF＆＃34; 。我不是用快递而是招摇。我写的代码是：

//Get the uploaded buffer
var _originalBuffer = req.swagger.params.uploadedFile.value.buffer;
let Duplex = require('stream').Duplex;

//Create stream from buffer. This stream is required later to send to cloud.
let _uploadedFileStream = new Duplex();
_uploadedFileStream.push(_originalBuffer);
_uploadedFileStream.push(null);

//Create base 64 string so that "PIEXIF" can read exif data from it.
const jpegData = "data:image/jpeg;base64, " + createStringFromBuffer(_originalBuffer, 'base64');

//Read exif data.
var _exifData = piexif.load(jpegData);

//Create a copy of exif data. Will be used to create a new image with updated orientation tag.
var _exifDataCopied = {};
for (var key in _exifData) {
    _exifDataCopied[key] = _exifData[key];
}

//Update orientation tag.
if (_exifDataCopied["0th"][piexif.ImageIFD.Orientation])
    _exifDataCopied["0th"][piexif.ImageIFD.Orientation] = 1;

//Example taken from https://www.npmjs.com/package/piexifjs
//From here onwards, there seems to be an issue.
var exifbytes = piexif.dump(_exifDataCopied);
var newData = piexif.insert(exifbytes, createStringFromBuffer(_originalBuffer, 'binary'));

var newJpeg = new Buffer(newData);

//Create a new stream and save it as image back.
let _updatedFileStream = new Duplex();
_updatedFileStream.push(newJpeg);
_updatedFileStream.push(null);

var fs = require('fs');

var writeStream = fs.createWriteStream("./uploads/" + "Whatever.jpg")

问题是代码没有抛出错误。图像也会保存在目录中，但已损坏。我无法预览它。既然，代码没有破坏任何地方，我很困惑可能是什么问题？将缓冲区转换为具有不同编码的字符串的函数（因为我需要它很多）是：

var createStringFromBuffer = function(_buffer, _encoding) {
    return Buffer.from(_buffer).toString(_encoding);
}

有人能说出我在误导的地方吗？我使用的是给定Here

的示例

NodeJS：使用PIEXIF更新Exif数据并保存图像

0 个答案: