A fun fact about PNG, the correct pronunciation is defined in the specification > PNG is pronounced “ping” See the end of Section 1 [0] 0: https://www.w3.org/TR/REC-png.pdf
Even though I know about this, I still pronounce it as letters. :)
A new PNG spec
421–430 of 622 posts
Re: A new PNG spec
#422A fun trick I do with my web based drawing tools is to save a JSON representation of your document as a comment field inside of a PNG. This way the doc you save is immediately usable as an image but can also be loaded back into the editor. Also means your downloads folder isn’t littered with unintelligible JSON files.
Macromedia did this when saving Fireworks files into PNG. Also, Adobe saves AI files into a PDF (every AI file is a PDF file), and Photoshop can save PSD files into TIFF files (people wonder why these TIFFs have several layers in Photoshop, but just one layer in all other software).
> Macromedia did this when saving Fireworks files into PNG.
I forgot about this..
Fireworks was my favorite image editor, I don't know that I've ever found one I love as much as I loved Fireworks. I'm not a graphics guy, but Fireworks was just fantastic.
Re: A new PNG spec
#423A fun trick I do with my web based drawing tools is to save a JSON representation of your document as a comment field inside of a PNG. This way the doc you save is immediately usable as an image but can also be loaded back into the editor. Also means your downloads folder isn’t littered with unintelligible JSON files.
That is also how Krita stores brushes. Unfortunately, that can cause some unexpected issues when there's too much data [1][2]. [1] - https://github.com/Draneria/Metallics-by-Draneria_Krita-Brus... [2] - https://krita-artists.org/t/memileo-impasto-brushes/92952/11...
If a patch is needed for libpng to get around the issue, maybe Krita should vendor libpng for usability. It's not unreasonable for people to want to create gigantic files like this.
Re: A new PNG spec
#424Reading the linked blog post on the new cICP chunk type [0], it looks like the "proper HDR support" isn't something that you couldn't already do with an embedded ICC profile, but instead a much-abbreviated form of the colorspace information suitable for small image files. [0] https://svgees.us/blog/cICP.html
PNG previously supported ICC v2. That was updated to ICC v4. However, neither of these are capable of HDR.
Maybe iccMAX supports HDR. I'm not sure. In either case, that isn't what PNG supported.
So something new was required for HDR.
Re: A new PNG spec
#425A fun trick I do with my web based drawing tools is to save a JSON representation of your document as a comment field inside of a PNG. This way the doc you save is immediately usable as an image but can also be loaded back into the editor. Also means your downloads folder isn’t littered with unintelligible JSON files.
> save a JSON representation of your document as a comment field inside of a PNG
Can you compress it? I mean, theoretically there is this 'zTXt' chunk, but it never worked for me, therefore I'm asking.
Re: A new PNG spec
#426A fun trick I do with my web based drawing tools is to save a JSON representation of your document as a comment field inside of a PNG. This way the doc you save is immediately usable as an image but can also be loaded back into the editor. Also means your downloads folder isn’t littered with unintelligible JSON files.
This is also what many AI image gen frontends do, saving the generation specs as comments so you can open the image and get prompt and settings (or, for, e.g., ComfyUI, full workflows) loaded to tweak.
Really, I think its pretty common for tools that work with images generally.
Re: A new PNG spec
#427Author here. Hello everyone!
Feel free to ask me anything.
I'll go ahead and dispel some doubts I already see here:
- It isn't really a "new format". It's an update to the existing format. - It is very backwards compatible. -- Old programs will load new PNGs to the best of their capability. A user will still know "that is a picture of a red apple".
There also seems to be some confusion about how PNGs work internally. Short and sweet: - There are chunks of data. -- Chunks have a name, which says what data it contains. A program can skip a chunk it doesn't recognize. - There is only one image stream.
Re: A new PNG spec
#428Earlier quoted context omitted.
In general, with some applications people hit the limits pretty quickly with PNG and JPG. In our use-case, the EXR format essentially meant a rendered part of the source image wouldn't be "overexposed" by the render pipeline, and layers could be later adjusted to better match in Resolve. Example: your scenes fireball simulation won't look like a fried egg photo from 1980 due to hitting 0xFF. If you've never encounter…
0xFF is 8-bit. PNG supports up to 16-bit. It always has. Plus, PNG now supports full HDR so the fireball won't look washed out. I think your experience is with some tool that made bad PNGs. That is a problem with the tool, not the format.
EXR stores the color-space information differently, and you missed the point.
Have a look at a tutorial that dives into the basic details, and consider learning something:
https://www.youtube.com/watch?v=pLt1230dtYE
https://www.youtube.com/watch?v=mb0b83MML78
https://www.youtube.com/watch?v=egtnkhuUe_E
PNG has its use-cases, and some people do expect that baked color-space garbage look given it dominates a lot of low-end media. Have a great day =3
Re: A new PNG spec
#429Re: A new PNG spec
#430A fun trick I do with my web based drawing tools is to save a JSON representation of your document as a comment field inside of a PNG. This way the doc you save is immediately usable as an image but can also be loaded back into the editor. Also means your downloads folder isn’t littered with unintelligible JSON files.
This is what stable-diffusion-webui does too (though the format is unfortunately plaintext); ComfyUI stores the node graph as JSON, etc.