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
|
## Read JPEG images in Go, quickly
This library is the fastest possible way to decode and encode JPEG images in Go.
We achieve this via cgo bindings to [libjpeg-turbo](http://libjpeg-turbo.virtualgl.org)
library.
The exact speed depends on the image and CPU. On Mac Book Pro, compared
to `image/jpeg` standard library, golibjpegturbo is:
* 6x faster when decoding
* 1.7x faster when encoding at quality level of 90%
You can rerun the benchmark on your machine with `go test -bench=.`
Additionally, unlike `image/jpeg`, this library can read JPEG images in CMYK format.
## Setup
Before you import library, you need to install libjpeg-turbo.
On Ubuntu: `sudo apt-get install libjpeg-turbo8-dev`.
On Mac OS X: `brew install libjpeg-turbo`
## Usage
`go get github.com/kjk/golibjpegturbo`
The API is the same as `image/libjpeg`:
```go
import "golibjpegturbo"
func decode(r io.Reader) (image.Image, error) {
return golibjpegturbo.Decode(r)
}
func encode(img image.Image) ([]byte, error) {
options := &golibjpegturbo.Options{Quality: 90}
var buf bytes.Buffer
err = golibjpegturbo.Encode(&buf, decodedImg, options)
if err != nil {
return nil, err
}
return buf.Bytes(), nil
}
```
More docs: http://godoc.org/github.com/kjk/golibjpegturbo
## Running a stress test
There's a stress test. If you have a directory with images, you can
do `go run stress_test/main.go -dir=$directory`.
The test loops infinitely and decodes/encodes the images to verify there
are no problems caused by incorrect `cgo` usage.
## License
MIT.
Written by [Krzysztof Kowalczyk](http://blog.kowalczyk.info/).
Inspired by [lye/libjpeg](https://github.com/lye/libjpeg) and [go-thumber](https://github.com/pixiv/go-thumber/tree/master/jpeg).
|
