Regressive JPEGs

113 points by vitaut 4 hours ago | 5 comments

cousin_it 1 hour ago |

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.

londons_explore 40 minutes ago | |

There are already webcams which do this- but they use a mime trick for 'multipart/x-mixed-replace'.

That's basically the server telling the client 'That data I just sent you, well now replace it with this new thing'.

No JavaScript needed, and can work with plain http and jpeg

xnx 47 minutes ago |

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.

londons_explore 44 minutes ago | |

You can also deliberately have the server sending data at the right rate for the right playback time.

Easy enough to add a delay() each frame if your server is python/nodejs/PHP/whatever

schobi 56 minutes ago |

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!