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
|
/*
* Copyright (C) 2014 ~ 2018 Deepin Technology Co., Ltd.
*
* Author: jouyouyun <jouyouwen717@gmail.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package graphic
import (
"bytes"
"encoding/base64"
"fmt"
"image"
"io/ioutil"
"strings"
)
// ConvertImageToDataUri convert image file to data uri.
func ConvertImageToDataUri(imgfile string) (dataUri string, err error) {
data, err := ioutil.ReadFile(imgfile)
if err != nil {
return
}
f, err := GetImageFormat(imgfile)
if err != nil {
return
}
contentType := imageFormatToDataUriContentType(f)
dataUri = fmt.Sprintf("data:%s;base64,%s", contentType, base64.StdEncoding.EncodeToString(data))
return
}
// ConvertImageToDataUri convert image.Image object to data uri.
func ConvertImageObjectToDataUri(img image.Image, f Format) (dataUri string, err error) {
byteBuf := new(bytes.Buffer)
err = doSaveImage(byteBuf, img, f)
if err != nil {
return
}
data := byteBuf.Bytes()
contentType := imageFormatToDataUriContentType(f)
dataUri = fmt.Sprintf("data:%s;base64,%s", contentType, base64.StdEncoding.EncodeToString(data))
byteBuf.Reset()
return
}
// ConvertDataUriToImage convert data uri to image file.
func ConvertDataUriToImage(dataUri string, dstfile string, f Format) (err error) {
img, err := LoadImageFromDataUri(dataUri)
if err != nil {
return
}
return SaveImage(dstfile, img, f)
}
// LoadImageFromDataUri convert data uri to image object.
func LoadImageFromDataUri(dataUri string) (img image.Image, err error) {
strs := strings.Split(dataUri, ",") // ;base64,
if len(strs) != 2 {
err = fmt.Errorf("invalid data uri: %s", dataUri)
return
}
data, err := base64.StdEncoding.DecodeString(strs[1])
if err != nil {
return
}
r := bytes.NewReader(data)
img, _, err = image.Decode(r)
return
}
func imageFormatToDataUriContentType(f Format) (contentType string) {
contentType = fmt.Sprintf("image/%s", f)
return
}
|
