A Real World Example of How Sony 11+7 Bit Lossy Compression Creates Ugly Block Artifacts
Related: data compression, Sony, Sony A7R, Sony A7R II, Sony A7R III, Sony A7R IV, Sony mirrorless
Today I was processing an extreme dynamic range image (bristlecone tree trunk against a dusk sky) and I run into some ugly block artifacts.
As shown, these block artifacts are the results of Sony 11+7 bit lossy compression. These occur when the brightness differential exceeds the 11 bit range, generating these ugly and not so easy to fix garbage patches.
Lesson learned: use uncompressed raw file format in such cases—but one does one know it is needed? The camera could warn about it and auto-switch the format on a file-by-file basis, but that’s apprently too hard for Sony to figure out.
What screwed up priorities are in place that Sony engineering is unable to offer a lossless compressed raw format? Which virtually every other camera vendor offers. It is a long-solved technical problem posing no challenge to for any competent organization. Therefore, it’s a bad judgment/management situation. It’s unbelievable that this situation exists, 5 years after I first wrote about it and from a company claiming 15-bit dynamic range for the Sony A7R IV—seriously?!.
A lossless compressed raw file format has no quality issues (same quality as uncompressed raw) and often saves 50% or more in file size. Why should Sony mirrorless shooters seeking full quality continue to suffer from the wasted space of huge files and wasted time of double-size backups? It’s insane.
I’m pissed off that my images are mangled when this need never happen. And I am not on board with shooting uncompressed raw all the time, as it is a tremendous storage and backup burden.
See also data compression and Sony A7R File Sizes, Lossy Compression and Sony 11+7 bit Lossy Compression: Gapping and Sony Announces an Uncompressed File Format for A7R II and Future Cameras.
