Oh wow.

I was working with Glenn on GitHub and I didn't know.

https://github.com/glennrp/libpng/pull/177 was my last interaction with him. He seemed to really care about libpng and making it better.

PNG is a really underappreciated format. It's amazing how an 8-bit PNG can make a lot of icons super small without losing quality. Without PNG being held up as open software we would most likely not have the graphics we take for granted now.

I don't know him as a human being, but I would hope he is a great one, too.

Thank you Glenn.

PNG is basically zip with some extra tricks. The advantage in PNG is not how well it compresses.

> PNG is basically zip with some extra tricks.

Sure, if with "some extra tricks" you mean "four relatively simple scanline filters[0] that nevertheless Paretro Principle[1] the heck out of more complex forms of lossless compression".

Especially Paeth is amazing in how it makes gradients so much cheaper than naive approaches with such a simple formula.

Similarly relying on DEFLATE is smart too, as that means any improvement to that format can be safely applied to PNG as well, like with zopflipng[1].

[0] https://www.w3.org/TR/PNG-Filters.html

[1] https://github.com/google/zopfli/blob/master/README.zopflipn...

Sure it’s smart and well thought-out. It’s not worth the Nobel prize though.

The achievement in PNG is in beating the de facto standard when it was created, GIF. That’s pretty difficult because GIF is almost good enough, except for features that are hard to explain to non technical people. They don’t care that GIF was covered by software patents and they don’t know about 1 bit transparency and color palettes. They know that GIF is supported in all software they care about, and that GIF has animation to boot.

I've noticed a lot of us despair about whether we can contribute as an engineer as we get older. I didnt know Glenn but to be a badass coder and maintainer of hugely popular library at his age is truly inspirational.

RIP.

I was always impressed at the level of legacy support in libpng. Even 1.0.x still gets security updates now and then.

RIP and a job well done.

I prefer PNGs to almost any other format in my documents, since they seem to be almost lossless and also dont bloat the size. Such a great work must surely be a product of a brilliant Mind. RIP Glenn Randers-Pehrson.

> they seem to be almost lossless

The should be just plain (completely) lossless unless your image encoder is doing something evil behind your back.

I thought there are "lossy" encoders that do things like dither and reduce the colorspace?

There are, but those are not the ones one thinks of by default when talking about PNG. If they do, they should clearly tell you they are doing something nonstandard.

This appears to be his LinkedIn page: https://www.linkedin.com/in/glenn-randers-pehrson-77110a101/

Started out as a geophysicist for a Texas oil company, then served in the military, then a number of physicist gigs with the government, including with the army and at Livermore Laboratory. His most recent gig is "(Volunteer) Software Developer and Maintainer" -- Jan 1995 - Present"

Was first exposed to .PNG in Macromedia Fireworks. Have loved it more than the other extensions ever since.

Me too— I thought it was cool how Fireworks used PNG as its native format, with extra metadata to keep layers and text editable.

Thanks Glenn; I still export to PNG all the time.

The very first PNG image is no more. It points to this:

http://homepages.rpi.edu/~randeg/paleo_pngs.html

Huh, right next to the death of Todd Boll. Really sad day today.

Rest in peace, Glenn.

Losslessness at rest we salute you.

Is there some reason we don't have a black bar on HN for this? Given the ubiquity of the PNG format, I would think his death is deserving of it. RIP.

Usually they're for household names ("household" within our industry anyway). That said, maybe we'll get one once the admins wake up. :)

Thanks for all the work Glenn.