1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
|
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);
});
|
