About DFJPEGTurbo

Objective-C libjpeg-turbo wrapper (JPEG image codec that uses SIMD instructions (MMX, SSE2, NEON) to accelerate baseline JPEG compression and decompression on x86, x86-64, and ARM systems). DFJPEGTurbo uses libjpeg-turbo version 1.3.0.

Requirements

iOS 6.0

Warning

There are two issues with libjpeg-turbo on iOS:

It's doesn't support ARM64
It's has the same performance as CGContextDrawImage on new CPUs.

Examples

Decompressing JPEG data

NSData *jpegData;
UIImage *image = [DFJPEGTurbo imageWithData:data];

Decompressing JPEG data with one of the libjpeg-turbo scale factors

NSData *jpegData;
// Scale must be implemented by libjpeg-turbon which supports only several scaling factors (1/1, 1/2, 1/4 etc).
// In other case the image is going to be cropped.
DFJPEGScale scale = DFJPEGScaleMake(1, 2); // 0.5 scale
UIImage *image = [DFJPEGTurbo imageWithData:jpegData orientation:UIImageOrientationDown scale:scale];

Benchmark

Apple A5X (armv7)

Input Image	SDWebImage	AFNetworking	DFJPEGTurbo	Avg. Ratio
2048x1536, 0.25 compression quality	218.29 ms	214.40 ms	121.46 ms	1.78
2048x1536, 0.50 compression quality	234.74 ms	238.26 ms	134.55 ms	1.75
2048x1536, 0.75 compression quality	230.02 ms	239.85 ms	154.50 ms	1.58

Installation

Current version (0.2.0) can be installed via Cocoapods.

pod 'DFJPEGTurbo', '~> 0.2'

Contacts

Alexander Grebenyuk

License

DFJPEGTurbo is available under the MIT license. See the LICENSE file for more info.

pkirchner/DFJPEGTurbo