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A new PNG spec

(www.programmax.net)
614 points bluedel | 1 comments | 24 Jun 25 13:01 UTC | HN request time: 0s | source
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LeoPanthera ◴[25 Jun 25 05:06 UTC] No.44373778[source]▶
> I know you all immediately wondered, better compression?. We're already working on that.

This worries me. Because presumably, changing the compression algorithm will break backwards compatibility, which means we'll start to see "png" files that aren't actually png files.

It'll be like USB-C but for images.

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mrheosuper ◴[25 Jun 25 06:20 UTC] No.44374139[source]▶
Does usb-c spec break backward compatibility ?, a 2018 macbook work perfectly fine with 2025 usb c charger
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danielheath ◴[25 Jun 25 06:37 UTC] No.44374221[source]▶
Some things don't work unless you use the right kind of USB-C cable.

EG your GPU and monitor both have a USB-C port. Plug them together with the right USB cable and you'll get images displayed. Plug them together with the wrong USB cable and you won't.

USB 3 didn't have this issue - every cable worked with every port.

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mrheosuper ◴[25 Jun 25 06:40 UTC] No.44374244[source]▶
That is not backward compatible problem. If a cable that does 100w charging when using pd2.0, but only 60w when using with pd3.1 device, then i would agree with you.
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yoz-y ◴[25 Jun 25 06:51 UTC] No.44374298[source]▶
The problem is not backward compatibility but labeling. A USB-C cable looks universal but isn’t. Some of them just charge, some do data, some do PD, some give you access to high speed. But there is no way to know.

I believe the problem here is that you will have PNG images that “look” like you can open them but can’t.

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mrheosuper ◴[25 Jun 25 07:01 UTC] No.44374367[source]▶
the parent said "changing the compression algorithm will break backwards compatibility", which i assume is something works now won't work in the future. The usb-c spec is intentionally trying to avoid that.
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danielheath ◴[25 Jun 25 07:10 UTC] No.44374409[source]▶
Today, I can save a PNG file off a random website and then open it.

If PNG gets extended, it's entirely plausible that someone will view a PNG in their browser, save it, and then not be able to open the file they just saved.

There are those who claim "backwards compatibility" doesn't cover "how you use it" - but roughly none of the people who now have to deal with broken software care about such semantic arguments. It used to work, and now it doesn't.

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1. fc417fc802 ◴[25 Jun 25 07:49 UTC] No.44374663[source]▶
The alternative is the website operator who wants to save on bandwidth instead adopts JXL or WEBP or what have you and ... the end user with old software still can't open it.

It's a dichotomy. Either the provider accommodates users with older software or not. The file extension or internal headers don't change that reality.

Another example, new versions of PDF can adopt all the bells and whistles in the world but I will still be saving anything intended to be long lived as 1/a which means I don't get to use any of those features.