Regressive JPEGs

I did something very similar with progressive (adam7 interlaced) PNG: https://www.da.vidbuchanan.co.uk/adamation/image.png

> so playback is entirely dependent on network delay

Ultimately true, but I set up my server to send each "frame" separately, with a fixed delay between each. Each frame is small so unless your network is unusually slow, the timing is set by my server.

> “Besides unconventional rickrolls and other trolling, this has no practical applications: there's no way to add timing information, so playback is entirely dependent on network delay.”

A progress bar for something that’s loading in parallel over the same network, to give the user an idea of how much the delay is?

That is 1. Cursed, and 2. Definitely in the right place here.

I wonder if and how you can use this for steganography, hiding data in plain sight. I bet most automated image analysis programs would only consider the final image. I sure some highschooler can use this to bypass their schools contentfilter

Now you just have to mod your webserver to send the image chunk by chunk (with waits in-between). That way network latency does not matter. Also it probably reduces artefacts as bytes from one frame most likely are received in one network packet.

I love the first JPEG where the final image is... a different picture of the cat. "The first images you see are just approximations to the final, exact version." Audience's heads nod in understanding

Nice! I think you can approximate timing somewhat, by making your web server create the "jpeg" on the fly and send it to the client in timed chunks. The source could even be a webcam, so the "jpeg" would go on forever.

> so playback is entirely dependent on network delay

You can use Service Worker to emulate a slow connection :)

Adjacent advice: I've recently played with opengl and jpeg turbo and I wanted to display images fast. I don't remember exact numbers, but enabling progressive for a jpeg was a significant slowdown for decoding. So if anyone like me is stuck with the old school advice that progressive is an nice to have, it's likely not. I personally don't remember any visual progressive image buildup in like decades, so it's not doing anything valuable at all.

This website appears to be maliciously using IP address blocking. Here is a less-censored link: https://web.archive.org/web/20260718065449/https://maurycyz....

Obviously the demonstrations that rely on server-side timing don't work through archive.org.

Wow, Firefox never fully loads the page, while WebKit fails to load it altogether, instead it displays "Operation was cancelled" in system font after a short freeze. I didn't manage to see the images change in any way as the post would suggest though, which left me confused.

my kinda hackin' so much creative potential ...

I tried to think about difficult ways to compute the high frequency coefficients to work from the "wrong" coefficients of the first image...

But this is clever - just smash them together. Low frequency of one image concatenated with high frequency from another. This works surprisingly well!

Excellent hack! Should definitely be possible to make an animated gif to jpeg converter. I guess the animation could be slowed a little by repeating frames.

insanity of content aside, that's a really nice website. Kudos.

I wonder if you can do this in JPEG-XL. I know that that has actual animation support, but this would be a different thing.

If the online porn industry hasn't used it, it's probably worthless. Still funny, though.

Safari just freezes in place until the image is entirely finished downloading.

Now, stuff like _this_ is why I keep coming back to HN.

hmm interesting

My jaw dropped. Very cool. Thanks for sharing.

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Thanks for sharing