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Comment by functionmouse | Hacker News Reader

there is no such thing as "near lossless"

There is, after you define what you’re ready to loose and understand the lossy space. That’s how we came up with mobile cellphones, audio and video codecs etc. Literally powering all modern devices we use.

Actually, all of those things are considered "lossy".

Yes, anything not lossless is lossy. Near-lossless is not lossless, so it is lossy. I hope we speak the same language

So then ... "lossy"

theres a big difference between 99% quality and 30%. near lossless is a good name for the first one. if you treat it in a binary way where everything short of 100 falls into one "lossy" bucket you lose all the practical differences that make one encoding much better than another.

> theres a big difference between 99% quality and 30%.

sure

> if you treat it in a binary way where everything short of 100 falls into one "lossy" bucket you lose all the practical differences that make one encoding much better than another.

no; lossless is an inherently binary term. and I don't lose all the practical differences of better lossy encoders by understanding that; I'm not just going to start using mp3 96k because I have an understanding of lossless vs lossy encoders...

Lossless is an objectively binary term.

Lossless is objective for information theory. To get from the real world to digital world you need an analog to digital converter, this process is by definition lossy. We are interested in the real world, and information is pure but never represents exactly reality.

Lossyness is baked into our problem statement here.

Using terms like near lossless means we think we are very close to reality for what we’re trying to do

mp3 is near lossless

I agree with you somewhat, and I like what is described in the article. But I also feel like we are diluting the meaning of the word to make things sound better. Lossy/Lossless is inherently binary, and it carries a specific meaning. It would not detract from the work at all if it was described differently.

You can't be a little bit on fire :)

Yes of course. A compression algorithm which just stores the number of bits and decodes all bits as zeros is also lossy.

A floating-point compression algorithm which reconstructs the elements so they differ by at most one ULP[1] compared to the original value is, no surprise, also lossy.

Being able to communicate that an algorithm is closer to the latter than the former is useful, hence terms like "near-lossless".

[1]: https://en.wikipedia.org/wiki/Unit_in_the_last_place

yes, your are right. what heading would you have taken here?

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