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FLIF – Free Lossless Image Format

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Re: FLIF – Free Lossless Image Format

#101

Post by pferde »

matzipan wrote: post #41
pferde wrote: post #32

Earlier quoted context omitted.

If the compression is good enough, always. Lossy compression was born out of necessity, after all.

It was not born out of necessity. It was born because of the way your brain percieves the images. There is no need in adding detail if your brain can live happily without it. And if FLIF achieves such great lossless compression, imagine what amazing compression you can achieve with lossy compression.

Let's take a step back. Why did developers start to think about how the brain perceives details and how to trick it in the first place? Out of a necessity to save bandwidth and/or storage space.

Re: FLIF – Free Lossless Image Format

#102

Post by timsneath »

Loque wrote: post #60
sccxy wrote: post #7

Earlier quoted context omitted.

Safari is much bigger problem than Edge/IE. No hope for WebM in Safari. WebM for Edge is in development.

It really depends on what it is - Edge is missing some rather fundamental modern CSS features (filters immediately springs to mind).

Actually, Edge has CSS filters as of last November: https://wpdev.uservoice.com/forums/257854-microsoft-edge-dev...

Test drive site here: https://dev.windows.com/en-us/microsoft-edge/testdrive/demos...

Re: FLIF – Free Lossless Image Format

#103

Post by jonsneyers »

joosters wrote: post #88
pornel wrote: post #80

Everyone loves the "responsive loading" feature, but that's not even the novel thing about the format (JPEG 2000 did it even better — 16 years ago)! The novel feature of this format is better entropy coding. FLIF decoder adds interpolation to make incomplete scans look nicer than in PNG, but that's a feature of the decoder, not the file format, so there's nothing stopping existing PNG decoders from copying that featu…

It shouldn't be used to replace JPEGs, but PNG files are widely used and would be good candidates for FLIF files instead. Also true for static GIFs, but presumably anyone still using them is not bothered about converting images to better formats.

FLIF also supports animation, so it could be used to replace animated GIF too.

Re: FLIF – Free Lossless Image Format

#104

Post by jonsneyers »

pornel wrote: post #80

Everyone loves the "responsive loading" feature, but that's not even the novel thing about the format (JPEG 2000 did it even better — 16 years ago)! The novel feature of this format is better entropy coding. FLIF decoder adds interpolation to make incomplete scans look nicer than in PNG, but that's a feature of the decoder, not the file format, so there's nothing stopping existing PNG decoders from copying that featu…

I agree with all of your comments. Some remarks though: (Disclaimer: I'm the author of FLIF)

- interpolation is not the only difference between PNG and FLIF in terms of progressive decoding. Another difference is that instead of doing the interlacing on RGB pixels, it does it on YCoCg pixels with priority given to Y, so intermediate steps are effectively chroma subsampled (or in other words you get luma faster at higher resolutions).

- lossless is indeed (currently?) too costly for photographic material on the web, because we can indeed afford some loss and still look good. However, you can still have a lossy encoder that uses a lossless format as a target: e.g. instead of encoding the deltas at full precision, you could throw away some least significant mantissa bits (those behave the most like incompressible noise) and still get visually good results.

- In future work: Progressive JPEG with the Huffman encoding replaced by FLIF's MANIAC entropy coding should be an interesting direction...

Re: FLIF – Free Lossless Image Format

#105

Post by cbhl »

jonsneyers wrote: post #103
joosters wrote: post #88

Earlier quoted context omitted.

It shouldn't be used to replace JPEGs, but PNG files are widely used and would be good candidates for FLIF files instead. Also true for static GIFs, but presumably anyone still using them is not bothered about converting images to better formats.

FLIF also supports animation, so it could be used to replace animated GIF too.

Presumably if you're using animated GIF you care about compatibility with exotic/older browsers, so at best you'd consider H.264/MP4 or SVG or Flash animations.

Re: FLIF – Free Lossless Image Format

#106

Post by cbhl »

teh_klev wrote: post #46

Do any of these newer/experimental schemes, such as this one, take into account other factors such as CPU load before declaring themselves as "better". For example this project seems pretty cool, but there's no data on how CPU bound, memory bound, I/O bound its decompression algorithm is. I guess what I'm asking is, if I hit a web page with 20 images @ 100k per image is it going to nail one or more cores at 100% and…

New codecs almost always use more CPU at first because they have to do pure-software decoding. However, if the bandwidth savings are good enough, and usage is ubiquitous enough, eventually the new format will be implemented in hardware decoding chips, which will bring power usage back down.

This is most noticeable in video formats; older devices only have MPEG-1/MPEG-2/MJPEG encoders/decoders (imagine a $20 DVD player or a old digital camera), whereas newer devices can do H.264 and/or VP9 encoding/decoding (new iPhone, new Smart HDTV).

Re: FLIF – Free Lossless Image Format

#107

Post by jonsneyers »

cbhl wrote: post #105
jonsneyers wrote: post #103

Earlier quoted context omitted.

FLIF also supports animation, so it could be used to replace animated GIF too.

Presumably if you're using animated GIF you care about compatibility with exotic/older browsers, so at best you'd consider H.264/MP4 or SVG or Flash animations.

Yes, being old/compatible is about the only advantage GIF has ;)

I agree that video formats are more suitable for many animations. Unless you have an animation where lossy is not desirable (e.g. cartoons or technical animations), and you only have pixels, no vectors. In that case FLIF (or APNG/MNG for that matter) can be a good choice.

Re: FLIF – Free Lossless Image Format

#108

Post by Veedrac »

teh_klev wrote: post #76
Veedrac wrote: post #71

Earlier quoted context omitted.

From the page, > Encoding and decoding speeds are acceptable, but should be improved From elsewhere: https://news.ycombinator.com/item?id=10318161 though the above is quite old.

Not trying to be obtuse, but that's just a subjective measure of how quick or not their algo is. It doesn't address (nor in the linked HN discussion) how efficient it is in terms of burning up CPU and battery.

The link has more concrete (non-subjective) timings.

Re: FLIF – Free Lossless Image Format

#109

Post by Houshalter »

tambourine_man wrote: post #69
Houshalter wrote: post #56

Earlier quoted context omitted.

This isn't how it actually works, but one way to turn a lossy decoder into a lossy one, is to send a diff of the actual pixels vs the encoded ones. Since the lossy compression will be close to correct, the diff will mostly be small values or 0's. Which is much easier to compress. Likewise you can turn any lossless compressor into a lossy one, by modifying the pixels that are the hardest to compress. E.g. if there is…

Kind of. Have you tried running a PNG compressor on a JPEG file? It is smaler than a straight to PNG file but nowhere near the size of the original JPG.

Well of course, JPEG artifacts aren't necessarily going to be easier for png to compress. You need to make modifications designed for png's algorithm. There are some tools that do this:

https://pngmini.com/lossypng.html

https://pngquant.org/

https://tinypng.com/

The resulting png's are much smaller. Though not necessarily as small as JPEG, it's in the same ballpark.

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