6 ms·

This is a strange test to do. The image he used is not really suited to PNG. It is more like a photograph, which is better in JPEG format, than an illustration,

by stewx 4y ago

This is a strange test to do. The image he used is not really suited to PNG. It is more like a photograph, which is better in JPEG format, than an illustration, which is better as a PNG. Furthermore, he doesn't even post the resulting compressed versions from each piece of software, just some console output and then a single "optimized PNG" image.

pmoriarty 4y ago
"The image he used is not really suited to PNG. It is more like a photograph, which is better in JPEG format, than an illustration, which is better as a PNG." I use PNGs to archive photographs because it's lossless, supports 16-bit images, and is well supported across most software. Not sure why you think it wouldn't be suitable for that. JPEGs, on the other hand, would not be at all suitable for this purpose, as they're lossy and only support 8-bit images.
- jhgb 4y ago
  Have you made any comparisons of your PNG files to, say, lossless WebP files? (Apparently there's also lossless mode in JPEG XS nowadays but that seems to be a very new option.)
  - pmoriarty 4y ago
    WebP can only handle 8-bit images. I need to scan and archive 16-bit images.
- ricardobeat 4y ago
  Archiving vs delivering images on the web, are pretty much extreme opposites in terms of size/bandwidth/quality requirements.
dontbenebby 4y ago
>This is a strange test to do. The image he used is not really suited to PNG. It is more like a photograph, which is better in JPEG format, than an illustration, which is better as a PNG. Isn't your comment why they used Lenna[1] so long -- it might be male gazey etc, but at least everyone is using the same male gazey softcore photo rather than sidetracking with arguments over image choice? [1] https://en.wikipedia.org/wiki/Lenna https://en.wikipedia.org/wiki/Lenna
- stewx 4y ago
  No. I was assuming that this blog post was about compressing PNG files for general use on web sites, but apparently that is not the case. He didn't actually state in the blog post what he was using the images for, but he says in a comment here that they need to be lossless. Usually that's not the case. JPEG works better for getting small sizes on photos for the web.
  - dontbenebby 4y ago
    But why not use the standard test image, absent political reasons?

by stewx 4y ago

pmoriarty 4y ago

"The image he used is not really suited to PNG. It is more like a photograph, which is better in JPEG format, than an illustration, which is better as a PNG." I use PNGs to archive photographs because it's lossless, supports 16-bit images, and is well supported across most software. Not sure why you think it wouldn't be suitable for that. JPEGs, on the other hand, would not be at all suitable for this purpose, as they're lossy and only support 8-bit images.

jhgb 4y ago
Have you made any comparisons of your PNG files to, say, lossless WebP files? (Apparently there's also lossless mode in JPEG XS nowadays but that seems to be a very new option.)
- pmoriarty 4y ago
  WebP can only handle 8-bit images. I need to scan and archive 16-bit images.
ricardobeat 4y ago
Archiving vs delivering images on the web, are pretty much extreme opposites in terms of size/bandwidth/quality requirements.

dontbenebby 4y ago

>This is a strange test to do. The image he used is not really suited to PNG. It is more like a photograph, which is better in JPEG format, than an illustration, which is better as a PNG. Isn't your comment why they used Lenna[1] so long -- it might be male gazey etc, but at least everyone is using the same male gazey softcore photo rather than sidetracking with arguments over image choice? [1] https://en.wikipedia.org/wiki/Lenna https://en.wikipedia.org/wiki/Lenna

stewx 4y ago
No. I was assuming that this blog post was about compressing PNG files for general use on web sites, but apparently that is not the case. He didn't actually state in the blog post what he was using the images for, but he says in a comment here that they need to be lossless. Usually that's not the case. JPEG works better for getting small sizes on photos for the web.
- dontbenebby 4y ago
  But why not use the standard test image, absent political reasons?