DFJPEGTurbo 0.2.1

Maintained by kean.

You want to add pod 'DFJPEGTurbo', '~> 0.2' similar to the following to your Podfile:

target 'MyApp' do
  pod 'DFJPEGTurbo', '~> 0.2'
end

Then run a pod install inside your terminal, or from CocoaPods.app.

Alternatively to give it a test run, run the command:

pod try DFJPEGTurbo

DFJPEGTurbo 0.2.1

By
Alexander Grebenyuk

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 1.4.1, which now includes arm64 support.

DFJPEGTurbo supports decompression of both baseline and progressive JPEG.

Requirements

iOS 6.0

Examples

Decompressing JPEG

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

Decompressing JPEG with one of the libjpeg-turbo scale factors

NSData *jpegData;
// Scale must be implemented by libjpeg-turbo which supports only several scaling factors (1/1, 1/2, 1/4 etc).
DFJPEGScale scale = DFJPEGScaleMake(1, 2); // 0.5 scale
UIImage *image = [DFJPEGTurboImageDecoder imageWithData:jpegData orientation:UIImageOrientationDown scale:scale];

Benchmark (Baseline JPEG)

Benchmark on older ARM-based systems (iPhone 4S, iPhone 5C) shows that libjpeg-turbo provides a very noticable performance boost over native CGContextDrawImage. However, libjpeg-turbo underperforms on newer systems (iPhone 6). For benchmark implementation see Demo/DFJPEGTurboBenchmark in a project folder.

iPhone 6 (Apple A8)

Input Image	CGContextDrawImage	libjpeg-turbo
1024x768, 0.3 compression quality	10.51 ms	9.75 ms
1024x768, 0.5 compression quality	10.56 ms	10.15 ms
1024x768, 0.7 compression quality	10.14 ms	11.61 ms
1024x768, 0.9 compression quality	10.13 ms	12.44 ms
2048x1536, 0.3 compression quality	41.60 ms	36.98 ms
2048x1536, 0.5 compression quality	33.46 ms	40.56 ms
2048x1536, 0.7 compression quality	33.85 ms	45.53 ms
2048x1536, 0.9 compression quality	34.79 ms	52.60 ms

iPhone 5C (Apple A6)

Input Image	CGContextDrawImage	DFJPEGTurbo
1024x768, 0.3 compression quality	42.47 ms	22.26 ms
1024x768, 0.5 compression quality	40.75 ms	23.28 ms
1024x768, 0.7 compression quality	40.51 ms	26.11 ms
1024x768, 0.9 compression quality	39.82 ms	29.77 ms
2048x1536, 0.3 compression quality	130.72 ms	81.95 ms
2048x1536, 0.5 compression quality	129.83 ms	86.50 ms
2048x1536, 0.7 compression quality	130.42 ms	98.17 ms
2048x1536, 0.9 compression quality	130.03 ms	106.18 ms

Contacts

License

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