google / decoder-benchmarks-for-rust

Benchmarks for Rust Image Decoders

This project runs benchmarks comparing Rust's native image decoders to ones written in C/C++. At the moment, we only look at decoding JPEG and PNG, but we hope to expand to more.

Running

To run these, you will need to have libjpeg-turbo installed and in your library path. For example on Mac OS:

> brew install jpeg-turbo
> RUSTFLAGS="-L/usr/local/opt/jpeg-turbo/lib" cargo bench

Results

The following results come from a run on a MacOS device with a 2.6GHz 6-Core Intel Core i7 processor and 16GB 2667 MHz DDR4 RAM.

This data is also presented in the graph below. Very roughly speaking, jpeg-decoder is slower than turbojpeg, taking roughly an additional 30% of time to decode the same image for larger images, but much longer on smaller images.

Test case	jpeg-decoder (ms)	turbojpeg (ms)	jpeg-decoder / turbojpeg
venice-10x15.jpg	0.1101	0.01993	552%
venice-20x30.jpg	0.1346	0.02691	500%
venice-50x75.jpg	0.2395	0.09818	244%
venice-100x150.jpg	0.577	0.2972	194%
venice-200x300.jpg	1.646	0.9864	167%
venice-500x750.jpg	8.483	5.633	151%
venice-1000x1500.jpg	31.82	22.74	140%
venice-1500x2250.jpg	73.13	49.36	148%
venice-2000x3000.jpg	126.2	84.25	150%

png and spng are much closer, with spng (a wrapper around a C++ library) being faster on larger images and png (written natively in Rust) being faster on smaller ones.

Test case	png (ms)	spng (ms)	png / spng
venice-10x15.png	0.009756	0.004822	202%
venice-20x30.png	0.01682	0.02313	73%
venice-50x75.png	0.06706	0.1285	52%
venice-100x150.png	0.3028	0.4702	64%
venice-200x300.png	1.244	1.371	91%
venice-500x750.png	6.907	6.765	102%
venice-1000x1500.png	28.48	25.22	113%
venice-1500x2250.png	66.81	58.06	115%
venice-2000x3000.png	128.9	102.4	126%

Further work

• Cover more image decoders.
• Find a good corpus of images to use.
• Investigate JPEG decoding at low image sizes.