ImageZero 5x faster than WebP

When the initial preview version of ImageZero (IZ) had been announced, many readers were interested in benchmarks against other compression algorithms, such as JPEG-2000 or Google’s new lossless WebP. At that time, however, the WebP software was not yet ready for testing; it was not possible to benchmark the decompression time, because the software could only convert back to PNG (and PNG encoding is known to be slow), and the compression crashed on large photos.

Luckily, the 0.2 version of the WebP tools has been released, and with this, the Lossless Photo Compression Benchmark has been updated to include results for WebP and ImageZero. Here are the most interesting results:

Software / License Size (% of 3.46 GB) Compression Decompression
uncompressed 100.0%
bzip2 -1 (bzip2 License) 56.3% 476 s 218 s
PNG (libpng License) 42.5% 844 s 72 s
ImageZero (BSD) 41.3% 23 s 21 s
JPEG-LS (HP License) 37.4% 107 s 92 s
lossless WebP (BSD) 35.6% 7525 s 110 s
Flic (proprietary) 30.0% 210 s 231 s
Gralic (proprietary) 28.1% 1734 s 1897 s