128 lines
3.0 KiB
JavaScript
128 lines
3.0 KiB
JavaScript
import EXIF from 'exif-js';
|
|
|
|
const MAX_IMAGE_DIMENSION = 1280;
|
|
|
|
const getImageUrl = inputFile => new Promise((resolve, reject) => {
|
|
if (window.URL && URL.createObjectURL) {
|
|
try {
|
|
resolve(URL.createObjectURL(inputFile));
|
|
} catch (error) {
|
|
reject(error);
|
|
}
|
|
return;
|
|
}
|
|
|
|
const reader = new FileReader();
|
|
reader.onerror = (...args) => reject(...args);
|
|
reader.onload = ({ target }) => resolve(target.result);
|
|
|
|
reader.readAsDataURL(inputFile);
|
|
});
|
|
|
|
const loadImage = inputFile => new Promise((resolve, reject) => {
|
|
getImageUrl(inputFile).then(url => {
|
|
const img = new Image();
|
|
|
|
img.onerror = (...args) => reject(...args);
|
|
img.onload = () => resolve(img);
|
|
|
|
img.src = url;
|
|
}).catch(reject);
|
|
});
|
|
|
|
const getOrientation = (img, type = 'image/png') => new Promise(resolve => {
|
|
if (type !== 'image/jpeg') {
|
|
resolve(1);
|
|
return;
|
|
}
|
|
|
|
EXIF.getData(img, () => {
|
|
const orientation = EXIF.getTag(img, 'Orientation');
|
|
resolve(orientation);
|
|
});
|
|
});
|
|
|
|
const processImage = (img, { width, height, orientation, type = 'image/png' }) => new Promise(resolve => {
|
|
const canvas = document.createElement('canvas');
|
|
[canvas.width, canvas.height] = orientation < 5 ? [width, height] : [height, width];
|
|
|
|
const context = canvas.getContext('2d');
|
|
|
|
switch (orientation) {
|
|
case 2:
|
|
context.translate(width, 0);
|
|
break;
|
|
case 3:
|
|
context.translate(width, height);
|
|
break;
|
|
case 4:
|
|
context.translate(0, height);
|
|
break;
|
|
case 5:
|
|
context.rotate(0.5 * Math.PI);
|
|
context.translate(1, -1);
|
|
break;
|
|
case 6:
|
|
context.rotate(0.5 * Math.PI);
|
|
context.translate(0, -height);
|
|
break;
|
|
case 7:
|
|
context.rotate(0.5, Math.PI);
|
|
context.translate(width, -height);
|
|
break;
|
|
case 8:
|
|
context.rotate(-0.5, Math.PI);
|
|
context.translate(-width, 0);
|
|
break;
|
|
}
|
|
|
|
context.drawImage(img, 0, 0, width, height);
|
|
|
|
canvas.toBlob(resolve, type);
|
|
});
|
|
|
|
const resizeImage = (img, type = 'image/png') => new Promise((resolve, reject) => {
|
|
const { width, height } = img;
|
|
|
|
let newWidth, newHeight;
|
|
|
|
if (width > height) {
|
|
newHeight = height * MAX_IMAGE_DIMENSION / width;
|
|
newWidth = MAX_IMAGE_DIMENSION;
|
|
} else if (height > width) {
|
|
newWidth = width * MAX_IMAGE_DIMENSION / height;
|
|
newHeight = MAX_IMAGE_DIMENSION;
|
|
} else {
|
|
newWidth = MAX_IMAGE_DIMENSION;
|
|
newHeight = MAX_IMAGE_DIMENSION;
|
|
}
|
|
|
|
getOrientation(img, type)
|
|
.then(orientation => processImage(img, {
|
|
width: newWidth,
|
|
height: newHeight,
|
|
orientation,
|
|
type,
|
|
}))
|
|
.then(resolve)
|
|
.catch(reject);
|
|
});
|
|
|
|
export default inputFile => new Promise((resolve, reject) => {
|
|
if (!inputFile.type.match(/image.*/) || inputFile.type === 'image/gif') {
|
|
resolve(inputFile);
|
|
return;
|
|
}
|
|
|
|
loadImage(inputFile).then(img => {
|
|
if (img.width < MAX_IMAGE_DIMENSION && img.height < MAX_IMAGE_DIMENSION) {
|
|
resolve(inputFile);
|
|
return;
|
|
}
|
|
|
|
resizeImage(img, inputFile.type)
|
|
.then(resolve)
|
|
.catch(() => resolve(inputFile));
|
|
}).catch(reject);
|
|
});
|