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 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:

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. Inspired by lye/libjpeg and go-thumber.