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Comment by zwieback | Hacker News Reader

That was my reaction. To be fair author says: "Of the formats listed here, TIFF is probably the one most likely to still be in wide use, but it has evolved into a more specialized format for professionals, in comparison to something like JPG."

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TGA files still show up in video game textures surprisingly often

That's probably because of how simple the format can be, with basically a header and footer tacked on to some RGBA data.

Surprisingly, with PNG, the deflate compression can slow you down, depending on what you are doing with the data. Saving a little bit of IO when you're accessing local data can turn out to be a losing proposition. TGA makes it easier to just shove pixels around, from program to program. TGA has all sorts of weird options which you can ignore, but with PNG, compression is mandatory.

I believe PNG supports uncompressed files, usually with a compression level = 0.

The data is still a Deflate stream, it's just that the deflate stream will be a series of literal blocks. The idea behind "uncompressed" is that you can just copy the data into memory, and level = 0 does not achieve that (you still have to decode the deflate stream).

... what decoding needs to be done on a series of literal blocks?

Not only that, but you can use TGA to write 16-bits per channel, which is very useful for raw data, or linear RGB colour spaces.

Does bitmap not tick all of these boxes?

I’ve never seen a 16 bits per channel BMP… is that even possible?

Half-Life is a little old but I wrote a parser for the .tga files it uses and it was simple (but reading the full spec... yeah it can get complicated with all the different flags).

When I worked on Call of Duty (~7 years ago) almost all of our source images were TGA. The runtime format that almost all games use are various block compressed formats (BC7, ASTC, etc) and usually these are grouped in some kind of package/archive format (although engines are moving away from that in order to stream at the asset level) and lz4 compressed on disk.

TIFFs are uncompressed or compressed with zip or lzw which is lossless. JPEGs are lossy and can't possibly be lossless. Pitting one as an alternative to the other is apples an oranges. When I read that sentence you quoted, I figured that the author is either lacking knowledge on the topic they're blogging about or they are trolling.

> JPEGs are lossy and can't possibly be lossless.

https://jpeg.org/jpegxl/

File formats exist that have JPEG in the name, that have certain features JPEG does not, and that cannot be decoded by all of these programs that can decode JPEG files. A JPEG XL file, for all intents and purposes, is not a JPEG file.

JPEG is a file format from decades ago. Obviously it’s possible to do better today. But it’s not possible to just invent a new format and have it as widely usable as JPEG. PNG did this with GIF but really only because GIF was seriously hobbled by software patents. It’s doubtful the millions of colors and alpha transparency would have won over compatibility otherwise.

TIFF is more like a container format that can contain a ton of different formats including many lossy formats. That also includes not just one but two different ways of embedding JPEG data (Compression 6 vs 7). See e.g. https://www.awaresystems.be/imaging/tiff/tifftags/compressio...

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