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@mannuelf
Created January 11, 2017 07:30
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dropzone.on("addedfile", function(origFile) {
var MAX_WIDTH = 800;
var MAX_HEIGHT = 600;
var reader = new FileReader();
// Convert file to img
reader.addEventListener("load", function(event) {
var origImg = new Image();
origImg.src = event.target.result;
origImg.addEventListener("load", function(event) {
var width = event.target.width;
var height = event.target.height;
// Don't resize if it's small enough
if (width <= MAX_WIDTH && height <= MAX_HEIGHT) {
dropzone.enqueueFile(origFile);
return;
}
// Calc new dims otherwise
if (width > height) {
if (width > MAX_WIDTH) {
height *= MAX_WIDTH / width;
width = MAX_WIDTH;
}
} else {
if (height > MAX_HEIGHT) {
width *= MAX_HEIGHT / height;
height = MAX_HEIGHT;
}
}
// Resize
var canvas = document.createElement('canvas');
canvas.width = width;
canvas.height = height;
var ctx = canvas.getContext("2d");
ctx.drawImage(origImg, 0, 0, width, height);
var resizedFile = base64ToFile(canvas.toDataURL(), origFile);
// Replace original with resized
var origFileIndex = dropzone.files.indexOf(origFile);
dropzone.files[origFileIndex] = resizedFile;
// Enqueue added file manually making it available for
// further processing by dropzone
dropzone.enqueueFile(resizedFile);
});
});
reader.readAsDataURL(origFile);
});
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