3 ms·

GP is correct, that’s the definition of “lossy”. We don’t need to invent ever new marketing buzzwords for well-established technical concepts.

AndrewDucker 2y ago
GP is incorrect. There is "Is identical", "looks identical" and "has lost sufficient detail to clearly not be the original." - being able to differentiate between these three states is useful.
- Rygian 2y ago
  Lossless means "is identical". The other two are variations of lossy. Calling one of them "perceptually lossless" is cheating, to the disadvantage of algorithms that honestly advertise themselves as lossy while still achieving "looks identical" compression.
  - protimewaster 2y ago
    It's a well established term, though. It's been used in academic works for a long time (since at least 1970), and it's basically another term for the notion of "transparency" as it relates to data compression.
  - TeMPOraL 2y ago
    I honestly don't notice this anymore. Advertisers have been using such language since time immemorial, to the point it's pretty much a rule that an adjective with a qualifier means "not actually ${adjective}, but kind of like it in ${specific circumstances}". So "perceptually lossless" just means "not actually lossless, except you couldn't tell it from truly lossless just by looking".
- tialaramex 2y ago
  Importantly the first one is parameterless, but the second and third are parameterized by the audience. For example humans don't see colour very well, some animals have much better colour gamut, while some can't distinguish colour at all.
  - travisjungroth 2y ago
    Perceptually lossless (nature for dogs) video compression at 15bit/s.
protimewaster 2y ago
But this marketing term has been regularly used in academic papers for nearly 50 years (or probably more), so it seems like it should get a pass IMO. It's also used in the first paragraph of the Wikipedia article on the term "transparency" as it relates to data compression.
Dylan16807 2y ago
It is in no way the definition of lossy. It is a subset of lossy. Most lossy image/video compression has visible artifacting, putting it outside the subset.

AndrewDucker 2y ago

GP is incorrect. There is "Is identical", "looks identical" and "has lost sufficient detail to clearly not be the original." - being able to differentiate between these three states is useful.

Rygian 2y ago
Lossless means "is identical". The other two are variations of lossy. Calling one of them "perceptually lossless" is cheating, to the disadvantage of algorithms that honestly advertise themselves as lossy while still achieving "looks identical" compression.
- protimewaster 2y ago
  It's a well established term, though. It's been used in academic works for a long time (since at least 1970), and it's basically another term for the notion of "transparency" as it relates to data compression.
- TeMPOraL 2y ago
  I honestly don't notice this anymore. Advertisers have been using such language since time immemorial, to the point it's pretty much a rule that an adjective with a qualifier means "not actually ${adjective}, but kind of like it in ${specific circumstances}". So "perceptually lossless" just means "not actually lossless, except you couldn't tell it from truly lossless just by looking".
tialaramex 2y ago
Importantly the first one is parameterless, but the second and third are parameterized by the audience. For example humans don't see colour very well, some animals have much better colour gamut, while some can't distinguish colour at all.
- travisjungroth 2y ago
  Perceptually lossless (nature for dogs) video compression at 15bit/s.

protimewaster 2y ago

But this marketing term has been regularly used in academic papers for nearly 50 years (or probably more), so it seems like it should get a pass IMO. It's also used in the first paragraph of the Wikipedia article on the term "transparency" as it relates to data compression.

Dylan16807 2y ago

It is in no way the definition of lossy. It is a subset of lossy. Most lossy image/video compression has visible artifacting, putting it outside the subset.