libjxl VS sumatrapdf

> Regarding JPEG XL's mobile support, it makes sense it would see limited development if the company that manages one of the biggest mobile players has been the greatest restriction on their success. The lack of support also disincentivises manufacturers to prioritise support.

There was literally no involvement from any hardware vendor in the standardization of JPEG XL. It went from a Call for Proposals in Sept 2018 to Committee Draft in Aug 2019 with very little time for industry feedback. Contrast this with AV1 which had involvement from hardware vendors Intel, NVIDIA, Arm, AMD, Broadcom, Amlogic from the beginning as well as companies who ship media on hardware at scale such as Cisco, Netflix, Samsung and yes Google. These companies reviewed and provided significant feedback on the format that made it suitable for hardware implementation.

https://news.ycombinator.com/threads?id=JyrkiAlakuijala is a lead on the project and a Google employee, and active in JPEG XL development https://github.com/libjxl/libjxl/commits?author=jyrkialakuij...

https://github.com/libjxl/libjxl/blob/main/doc/format_overvi... is a pretty detailed but good overview. The highlights are variable size DCT (up to 128x128), ANS entropy prediction, and chroma from luminance prediction. https://github.com/libjxl/libjxl/blob/main/doc/encode_effort... also gives a good breakdown of features by effort level.

For JPEG XL, refer to its format overview [1]. In short its lossless mode uses a combination of multiple techniques: the rANS coding with an alias table, LZ77, reversible color transforms, a general vector quantization that subsumes palettes, a modified Haar transform and a learnable meta-adaptive decision tree for context modelling.

One good thing about JPEG XL is that its lossy mode also largely uses the same tool, with a major addition of specialized quantization and context modelling for low- and high-frequenty components.

[1] https://github.com/libjxl/libjxl/blob/main/doc/format_overvi...

The cjxl source is here. If you spot any reason why -x strip=exif may not work, tell me.

The problem is that the instructions for actually running the WASM file are not that clear... the docs the author mentions shows how to compile to WASM, which is easy enough, but then here's the instructions to make that actually work in the browser:

https://github.com/libjxl/libjxl/blob/main/tools/wasm_demo/R...

Yeah, you need some mysterious Python script, a JS service worker at runtime, choose whether you want the WASM or WASM_SIMD target, use a browser that supports Threads and SIMD if you chose that, make sure to serve everything with the appropriate custom HTTP headers... just reading that, I can see that to get this stuff working on non-browser WASM targets would likely require expertise in WASM, which is the point of the OP. WASM's UX is just not there yet.

https://github.com/libjxl/libjxl#usage

> Specifically for JPEG files, the default cjxl behavior is to apply lossless recompression and the default djxl behavior is to reconstruct the original JPEG file (when the extension of the output file is .jpg).

I mean compiling a bleeding edge kicad, inkscape or jpeg-xl is easy. But will probably trash your system if you already have an older version installed.

But you look at your image viewer that could have the lossless indicator? (and there is an issue open to add this indicator to the jxl files)

https://github.com/libjxl/libjxl/issues/432

I’m curious, have you tried SumatraPDF (uses muPDF under the hood)?

https://github.com/sumatrapdfreader/sumatrapdf

Do you mind reporting those issues either to SumatraPDF at https://github.com/sumatrapdfreader/sumatrapdf/issues or directly to MuPDF at https://bugs.ghostscript.com/ if it also has the same issue? Thank you!

There are many wonderfully weird PDFs and epubs out there, but we do our best to fix issues. :)

FWIW, https://github.com/sumatrapdfreader/sumatrapdf/issues/1249 ("Support form filling for at least 1040 irs form") has a comment saying "MuPDF-GL has the capability to edit fields and save the PDF" of a 1040.

I have just learned the Firefox 93 added support XFA - https://techdows.com/2021/10/open-xfa-pdfs-in-firefox.html .

So it would appear there are free software solutions to XFA forms.

Just because something doesn't seem far-fetched to you, doesn't mean most people will regard it as far-fetched.

Many people all sorts of "sectarian objections" - far more than there are SovCits or other tax protesters. Stallman has never come across as a tax protester. Ergo, I think it's far-fetched that "sectarian objections" is strongly associated with tax protests.

Further, at https://stallman.org/archives/2017-may-aug.html we can read Stallman opinine that we need to "return to the "bad old days", when Americans in general could have a decent life, not penury; when the US could afford to build what the public needed instead of privatizing everything with a toll" by making taxation more progressive. At https://stallman.org/archives/2011-jan-apr.html we read he supports "The Fairness in Taxation Act [which] would raise taxes to 45% on incomes over a million dollars a year."

link for the lazy

If you are going to run something in wine, try sumatrapdf. It's FOSS but Windows only. (sadly, but runs great on wine)

Sumatra is Adobe free, free, and can remember the page you were on.

Sumatra PDF has always been my choice: minimal, lightweight, no bloat... just perfect!