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Lossless compression shouldn't matter. That's why it's called lossless.

by chx 2y ago

FollowingTheDao 2y ago
Lossless compression is still compressed. RAW photos are by definition not compressed. I do not care if you take out redundant bits, you are still taking them out. "Lossless compression uses an algorithm to shrink the image without losing any IMPORTANT data." and the algorithm decides what is important.
- xrisk 2y ago
  Lossless formats can compressed: take FLAC as an example.
- grujicd 2y ago
  If it's lossless then there's zero loss and can be returned to 100% original file. However if algorithm decides what's important than it's by definition not lossless. Wouldn't be surprised to get something like that from Apple, they love to twist words into something they're not for marketing reasons. Like when they say that non-pro Iphone 15 has 2x telephoto while it does not have telephoto lens at all, it's just a digital zoom which all other phones have.
- ubercow13 2y ago
  >I do not care if you take out redundant bits, you are still taking them out. Why does it matter? Why does that make Apple deceptive? Lossless compression is as good as no compression, the only difference is the decompression time. You could store the uncompressed RAW file on a filesystem with built in (lossless) compression, or you could store the losslessly compressed RAW file on a filesystem with no compression. Once you have opened the image in your editor or photo viewer, the bits in that application's memory that you are editing or viewing are identical. Moreover RAW does not mean 'uncompressed'. It doesn't even mean losslessly compressed. Often RAWs use lossy compression. Both Canon and Nikon RAWs can. https://photographylife.com/compressed-vs-uncompressed-vs-lossless-compressed-raw#nikon-raw-file-options https://photographylife.com/compressed-vs-uncompressed-vs-lo...
- sureIy 2y ago
  Have you ever zipped a file? Lossless does not mean data is lost. Lossless means data is not lost.
- spider-mario 2y ago
  > RAW photos are by definition not compressed. There is no such definition. Most cameras’ raw files nowadays are losslessly compressed. The compression being lossless means that the bits that were taken out can be reconstructed identically. It seems you might be confused as to what lossless compression means?
- 4ad 2y ago
  Yeah, no, lossless compression is like zipping the file. The exact data can be reproduced by decoding.
- chx 2y ago
  No, lossless compression uses an algorithm to shrink a file without any loss. It can be restored to the same bitstream. What you quoted is a confusing phrase: "visually lossless" which is in fact a lossy compression. It's like People's Republic which is neither a republic nor is it the People's, it's just a dictatorship. Finally, JPEG-XL supports both lossy and lossless compression.
  - FollowingTheDao 2y ago
    If you make a perfect physical copy of a picture, is it the same picture As the original?
    - chx 2y ago
      You can not do that. It is literally impossible to make a perfect physical copy. You can make a perfect copy of a file, however.
- 112233 2y ago
  I am confused. I assume you use camera that does not compress raw files. which vendor camera is that? Nikon compresses raws, Canon compresses raws, Sigma compresses raws, Sony compresses and processes (see "star eater") raws, most cameras process known defective pixels and subtract dark frame from long exposures before saving raw... Is it some kind of industrial camera you are talking about maybe?
  - FollowingTheDao 2y ago
    on Nikon cameras you can choose between compressed and uncompressed raw files. So I’m assuming you haven’t been around that many cameras. https://www.dpreview.com/forums/thread/4635816 https://www.dpreview.com/forums/thread/4635816
    - 112233 2y ago
      You just said yourself that raw files cannot be compressed... now you say that Nikon has your permission to compress raw files? What is the point you are trying to make? (Also, try reading the thread you linked and reconcile it somehow with your previous claim that losless compression of raw files is unacceptable)

Lossless compression shouldn't matter. That's why it's called lossless.

by chx 2y ago

Lossless compression shouldn't matter. That's why it's called lossless.

Lossless compression is still compressed. RAW photos are by definition not compressed. I do not care if you take out redundant bits, you are still taking them out. "Lossless compression uses an algorithm to shrink the image without losing any IMPORTANT data." and the algorithm decides what is important.

xrisk 2y ago
Lossless formats can compressed: take FLAC as an example.
grujicd 2y ago
If it's lossless then there's zero loss and can be returned to 100% original file. However if algorithm decides what's important than it's by definition not lossless. Wouldn't be surprised to get something like that from Apple, they love to twist words into something they're not for marketing reasons. Like when they say that non-pro Iphone 15 has 2x telephoto while it does not have telephoto lens at all, it's just a digital zoom which all other phones have.
ubercow13 2y ago
>I do not care if you take out redundant bits, you are still taking them out. Why does it matter? Why does that make Apple deceptive? Lossless compression is as good as no compression, the only difference is the decompression time. You could store the uncompressed RAW file on a filesystem with built in (lossless) compression, or you could store the losslessly compressed RAW file on a filesystem with no compression. Once you have opened the image in your editor or photo viewer, the bits in that application's memory that you are editing or viewing are identical. Moreover RAW does not mean 'uncompressed'. It doesn't even mean losslessly compressed. Often RAWs use lossy compression. Both Canon and Nikon RAWs can. https://photographylife.com/compressed-vs-uncompressed-vs-lossless-compressed-raw#nikon-raw-file-options https://photographylife.com/compressed-vs-uncompressed-vs-lo...
sureIy 2y ago
Have you ever zipped a file? Lossless does not mean data is lost. Lossless means data is not lost.
spider-mario 2y ago
> RAW photos are by definition not compressed. There is no such definition. Most cameras’ raw files nowadays are losslessly compressed. The compression being lossless means that the bits that were taken out can be reconstructed identically. It seems you might be confused as to what lossless compression means?
4ad 2y ago
Yeah, no, lossless compression is like zipping the file. The exact data can be reproduced by decoding.
chx 2y ago
No, lossless compression uses an algorithm to shrink a file without any loss. It can be restored to the same bitstream. What you quoted is a confusing phrase: "visually lossless" which is in fact a lossy compression. It's like People's Republic which is neither a republic nor is it the People's, it's just a dictatorship. Finally, JPEG-XL supports both lossy and lossless compression.
- FollowingTheDao 2y ago
  If you make a perfect physical copy of a picture, is it the same picture As the original?
  - chx 2y ago
    You can not do that. It is literally impossible to make a perfect physical copy. You can make a perfect copy of a file, however.
112233 2y ago
I am confused. I assume you use camera that does not compress raw files. which vendor camera is that? Nikon compresses raws, Canon compresses raws, Sigma compresses raws, Sony compresses and processes (see "star eater") raws, most cameras process known defective pixels and subtract dark frame from long exposures before saving raw... Is it some kind of industrial camera you are talking about maybe?
- FollowingTheDao 2y ago
  on Nikon cameras you can choose between compressed and uncompressed raw files. So I’m assuming you haven’t been around that many cameras. https://www.dpreview.com/forums/thread/4635816 https://www.dpreview.com/forums/thread/4635816
  - 112233 2y ago
    You just said yourself that raw files cannot be compressed... now you say that Nikon has your permission to compress raw files? What is the point you are trying to make? (Also, try reading the thread you linked and reconcile it somehow with your previous claim that losless compression of raw files is unacceptable)