js 写入图片Exif信息piexifjs
简介：
SamplesInsert Exif into jpegfunction handleFileSelect(evt) { var file = evt.
Samples
Insert Exif into jpeg
<input type="file" id="files" />
<script source="/js/piexif.js" />
<script>
function handleFileSelect(evt) {
var file = evt.target.files[0];
var zeroth = {};
var exif = {};
var gps = {};
zeroth[piexif.ImageIFD.Make] = "Make";
zeroth[piexif.ImageIFD.XResolution] = [777, 1];
zeroth[piexif.ImageIFD.YResolution] = [777, 1];
zeroth[piexif.ImageIFD.Software] = "Piexifjs";
exif[piexif.ExifIFD.DateTimeOriginal] = "2010:10:10 10:10:10";
exif[piexif.ExifIFD.LensMake] = "LensMake";
exif[piexif.ExifIFD.Sharpness] = 777;
exif[piexif.ExifIFD.LensSpecification] = [[1, 1], [1, 1], [1, 1], [1, 1]];
gps[piexif.GPSIFD.GPSVersionID] = [7, 7, 7, 7];
gps[piexif.GPSIFD.GPSDateStamp] = "1999:99:99 99:99:99";
var exifObj = {"0th":zeroth, "Exif":exif, "GPS":gps};
var exifbytes = piexif.dump(exifObj);
var reader = new FileReader();
reader.onload = function(e) {
var inserted = piexif.insert(exifbytes, e.target.result);
var image = new Image();
image.src = inserted;
image.width = 200;
var el = $("<div></div>").append(image);
$("#resized").prepend(el);
};
reader.readAsDataURL(file);
}
document.getElementById('files').addEventListener('change', handleFileSelect, false);
</script>
Read Exif Values
var reader = new FileReader();
reader.onloadend = function(e) {
var exifObj = piexif.load(e.target.result);
for (var ifd in exifObj) {
if (ifd == "thumbnail") {
continue;
}
console.log("-" + ifd);
for (var tag in exifObj[ifd]) {
console.log(" " + piexif.TAGS[ifd][tag]["name"] + ":" + exifObj[ifd][tag]);
}
}
};
reader.readAsDataURL(file);
Generates Rotated JPEG
function postJpeg (binStr) {
var array = [];
for (var p=0; p<data.length; p++) {
array[p] = data.charCodeAt(p);
}
var u8array = new Uint8Array(array);
var req = new XMLHttpRequest();
req.open("POST", "/jpeg", false);
req.setRequestHeader('Content-Type', 'image/jpeg');
req.send(u8array.buffer);
}
function previewJpeg(evt) {
var files = evt.target.files;
var previewDiv = $("#preview");
for (var i=0; i<files.length; i++) {
var file = files[i];
if (!file.type.match('image/jpeg.*')) {
continue;
}
var reader = new FileReader();
reader.onload = function(e) {
var exif = piexif.load(e.target.result);
var image = new Image();
image.onload = function () {
var orientation = exif["0th"][piexif.ImageIFD.Orientation];
var canvas = document.createElement("canvas");
canvas.width = image.width;
canvas.height = image.height;
var ctx = canvas.getContext("2d");
var x = 0;
var y = 0;
ctx.save();
if (orientation == 2) {
x = -canvas.width;
ctx.scale(-1, 1);
} else if (orientation == 3) {
x = -canvas.width;
y = -canvas.height;
ctx.scale(-1, -1);
} else if (orientation == 3) {
x = -canvas.width;
y = -canvas.height;
ctx.scale(-1, -1);
} else if (orientation == 4) {
y = -canvas.height;
ctx.scale(1, -1);
} else if (orientation == 5) {
canvas.width = image.height;
canvas.height = image.width;
ctx.translate(canvas.width, canvas.height / canvas.width);
ctx.rotate(Math.PI / 2);
y = -canvas.width;
ctx.scale(1, -1);
} else if (orientation == 6) {
canvas.width = image.height;
canvas.height = image.width;
ctx.translate(canvas.width, canvas.height / canvas.width);
ctx.rotate(Math.PI / 2);
} else if (orientation == 7) {
canvas.width = image.height;
canvas.height = image.width;
ctx.translate(canvas.width, canvas.height / canvas.width);
ctx.rotate(Math.PI / 2);
x = -canvas.height;
ctx.scale(-1, 1);
} else if (orientation == 8) {
canvas.width = image.height;
canvas.height = image.width;
ctx.translate(canvas.width, canvas.height / canvas.width);
ctx.rotate(Math.PI / 2);
x = -canvas.height;
y = -canvas.width;
ctx.scale(-1, -1);
}
ctx.drawImage(image, x, y);
ctx.restore();
var dataURL = canvas.toDataURL("image/jpeg", 1.0);
var jpegBinary = atob(dataURL.split(",")[1]);
var div = $("<div></div>");
div.append(canvas);
var button = $("<button>post this image</button>");
button.click(function () {
//postJpeg(jpegBinary);
});
previewDiv.prepend(div).prepend(button);
};
image.src = e.target.result;
};
reader.readAsDataURL(file);
}
}
document.getElementById("files").onchange = previewJpeg;
GPS Coordinates
var lat = 59.43553989213321;
var lng = 24.73842144012451;
gpsIfd[piexif.GPSIFD.GPSLatitudeRef] = lat < 0 ? 'S' : 'N';
gpsIfd[piexif.GPSIFD.GPSLatitude] = piexif.GPSHelper.degToDmsRational(lat);
gpsIfd[piexif.GPSIFD.GPSLongitudeRef] = lng < 0 ? 'W' : 'E';
gpsIfd[piexif.GPSIFD.GPSLongitude] = piexif.GPSHelper.degToDmsRational(lng);
Node.js
var piexif = require("piexifjs");
var fs = require("fs");
var filename1 = "in.jpg";
var filename2 = "out.jpg";
var jpeg = fs.readFileSync(filename1);
var data = jpeg.toString("binary");
var zeroth = {};
var exif = {};
var gps = {};
zeroth[piexif.ImageIFD.Make] = "Make";
zeroth[piexif.ImageIFD.XResolution] = [777, 1];
zeroth[piexif.ImageIFD.YResolution] = [777, 1];
zeroth[piexif.ImageIFD.Software] = "Piexifjs";
exif[piexif.ExifIFD.DateTimeOriginal] = "2010:10:10 10:10:10";
exif[piexif.ExifIFD.LensMake] = "LensMake";
exif[piexif.ExifIFD.Sharpness] = 777;
exif[piexif.ExifIFD.LensSpecification] = [[1, 1], [1, 1], [1, 1], [1, 1]];
gps[piexif.GPSIFD.GPSVersionID] = [7, 7, 7, 7];
gps[piexif.GPSIFD.GPSDateStamp] = "1999:99:99 99:99:99";
var exifObj = {"0th":zeroth, "Exif":exif, "GPS":gps};
var exifbytes = piexif.dump(exifObj);
var newData = piexif.insert(exifbytes, data);
var newJpeg = new Buffer(newData, "binary");
fs.writeFileSync(filename2, newJpeg);
https://github.com/hMatoba/piexifjs
