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What’s the best lossless image format?

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Re: What’s the best lossless image format?

#161

Post by JyrkiAlakuijala »

Melatonic wrote: post #72
detuur wrote: post #69

Earlier quoted context omitted.

How do EXR and JXL compare to each other, feature-wise?

I have never used JXL honestly - no job I have had it was ever even considered. Given the Jpeg in the name I doubt any pro studio would consider it given the other options do everything needed. DPX is basically the older standard for film and EXR is the newer one. edit: Just looked at the specs and JpegXL is definitely marketed at least more as a web end viewing file type. It does higher color depths (up to 16 bit) w…

The default implementation has more than 1000 more dynamic than the human eye or the best digital movie theaters. It would be possible to compress the highest quality photography with JPEG XL without introducing quality problems.

Likely you get 1/5th of the file size from EXR -- smaller file sizes can improve some web based workflows -- for example when an advertising team is distributed, or partially in work-from-home mode.

Bringing the quality of professional photography to the masses is another thing. Today, mobile phones rarely have too much capacity and many users are fighting with their memory space getting full. There, uncompressed or poorly-compressed formats are not a realistic or cost-efficient option.

Re: What’s the best lossless image format?

#162

Post by bob1029 »

mwcampbell wrote: post #156
bob1029 wrote: post #61

Earlier quoted context omitted.

Encoding speed can be very important, especially if you are seeking to decode the resulting image as quickly as possible at all times. Certain image formats are wildly better real-time containers than others. Encoding speed is irrelevant unless it's very low or very high. Most people are thinking amortize the decode against the encode and don't even consider what would happen if you took it into the other extreme. Di…

What do you think about MJPEG versus RFB (the VNC protocol)? I know that in modern VNC implementations, at least unofficial ones, JPEG is one of the available encodings. Still, IIUC, the big difference is that with MJPEG, the encoder sends a complete JPEG image for each frame, while this doesn't need to be the case with RFB.

I didn't know RFB was a thing. I will be looking into this.

What I really want is to be able to send an initial jpeg keyframe to the client, and then use some application-level heuristic to determine if I should then send a delta-encoded frame (what to change based upon the prior) or another keyframe. For 90%+ of my frames, using a prior frame and indicating deltas would be far more efficient than sending a keyframe each time. Maintaining the previous frames on the server per-client is not a huge deal and would not impact latency if done properly.

I wonder if there is some way I can use jpeg itself to half-ass this sort of approach in the browser. Maybe... encode keyframes at ~80% quality and delta frames at 100% (still not guaranteed, I know). Maybe canvas compositing or simple buffer tricks with bitmaps could get ~95% of the way there. For my application, the pixels don't have to be perfect or accurate to any particular standards.

Re: What’s the best lossless image format?

#163

Post by mwcampbell »

bob1029 wrote: post #162
mwcampbell wrote: post #156

Earlier quoted context omitted.

What do you think about MJPEG versus RFB (the VNC protocol)? I know that in modern VNC implementations, at least unofficial ones, JPEG is one of the available encodings. Still, IIUC, the big difference is that with MJPEG, the encoder sends a complete JPEG image for each frame, while this doesn't need to be the case with RFB.

I didn't know RFB was a thing. I will be looking into this. What I really want is to be able to send an initial jpeg keyframe to the client, and then use some application-level heuristic to determine if I should then send a delta-encoded frame (what to change based upon the prior) or another keyframe. For 90%+ of my frames, using a prior frame and indicating deltas would be far more efficient than sending a keyframe…

In case you're interested, here's a permissively licensed server-side implementation of the protocol, including all major codecs, in C: https://github.com/any1/neatvnc

Re: What’s the best lossless image format?

#164

Post by F-app »

High quality? Less size?

Most importantly, Microsoft and Apple don't like the new image format. They are founding members of AOM, but they reject AVIF. Most browsers using Blink engines, including Chrome, support avif, but not Edge. Safari? Of course not. Safari is Apple's version of Internet Explorer. The fact that Apple devices cannot use webp efficiently is why many webmasters and service managers still do not adopt webp.

Re: What’s the best lossless image format?

#165

Post by axiolite »

Wowfunhappy wrote: post #97
axiolite wrote: post #92

Earlier quoted context omitted.

> Itanium was better than AMD64, No, AMD64 is far superior, Itanium's benefits never materialized. Any BOTH offer backwards compatibility, anyhow. > DVORAK is better than QWERTY, Not by enough to matter except in extreme circumstances. I say this as a Dvorak typist. > I'm sure Esperanto is lightyears ahead of the monstrosity that is English. It's not. It is needlessly complicated. "Basic," "Simple," or "Technical" En…

ARM enabled a class of devices that x86 outright didn't support at the time (and largely still does not). In my eyes, that's the exception to the rule: when something is not merely incrementally better, but actually a difference in kind. That's what it takes to supersede backwards compatibility. I said in my last post that I expect h.264 to become the MP3 of video files—but if that doesn't happen, I suspect it will b…

> ARM enabled a class of devices that x86 outright didn't support at the time (and largely still does not).

What time, and which class of devices? Certainly it's true of very low-power embedded devices, but those aren't of particular interest... Embedded devices can easily switch between architectures without end users even noticing.

If we are referring to ARM being used for more computationally intensive devices... Like smart phones, tablets, and servers, then x86 has always had competitive options.

The earliest couple Nokia Communicators were x86 based, not ARM. Years before they switched to ARM, the National Semiconductor (later AMD) Geode processors debuted and were surely competitive with ARM, having power ratings as low as 0.7watt. Blackberry phones came years later, and iPhone and Android devices much later yet. The OLPC project using Geode CPUs on their XO-1 certainly proves their viability.

Re: What’s the best lossless image format?

#166

Post by ComputerGuru »

lajamerr wrote: post #30
ComputerGuru wrote: post #27

Earlier quoted context omitted.

I’ve read up about JPEG XL in the past but a question just occurred to me: is it just an image format or is it also a document format? Can it replace TIFF as a container for multi-page documents/images?

No, it's not a document format. JPEG XL won't replace TIFFs by and large because it has a different use case. TIFFs are more in-line with a combination of FLAC/WAV from the audio world. It's meant for raw data used in production/manipulation. As a professional you would work with TIFFs/RAW photo formats and then master it in JPEG XL for mass-consumption.

I’m aware that it isn’t meant to replace TIFF, but merely having document/multi-page support wouldn’t do that (or at least, not for most pro usages). There’s a severe dearth of consumer-friendly multi-page static image containers that don’t start with the letters P and D and end with F, and it would be great if someone in a position of influence would suggest such a format (especially if it really were just “multiple page support” and not “everything plus the kitchen sink masquerading as a multi-page image/document format).
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