Comments on: Compression using Canvas and PNG

By: Anne van Kesteren

Anne van Kesteren — Sat, 10 May 2008 08:24:27 +0000

p01, you can’t control the resolution of the datastore, it’s determined by the browser and is orthogonal to canvas or CSS pixels.

By: Avataristic

Avataristic — Thu, 08 May 2008 12:09:18 +0000

A clever technique but couldn’t you achieve the same result just depending on web/app-server compression by mime type?

By: Mathieu \'p01\' Henri

Mathieu \'p01\' Henri — Wed, 07 May 2008 10:50:55 +0000

Laurian: there is no EXIF library, since there is no cross browser way to read binary files.

By: Laurian

Laurian — Wed, 07 May 2008 08:20:15 +0000

Great, imagine that you can embed metadata and handling code in your sprites.

OTOH, is there any js library for reading EXIF metadata client-side?

By: Mathieu \'p01\' Henri

Mathieu \'p01\' Henri — Tue, 06 May 2008 08:47:26 +0000

Anne: that’s why Jacob Seidelin sets both the internal resolution and the “CSS” resolution of the Canvas ;)

By: locdev

locdev — Tue, 06 May 2008 08:10:30 +0000

try to just print-scr the code and OCR it back clientside ;)

By: Anne van Kesteren

Anne van Kesteren — Tue, 06 May 2008 07:35:53 +0000

FWIW, in theory this could break if the canvas backing store uses 200×200 for 100×100 canvas pixels for instance as getImageData returns the backing store data…

By: Kit

Kit — Tue, 06 May 2008 00:58:18 +0000

To say the least, this idea is genius.

Once browser compatibility improves, I can see this method being pretty widespread; it’s gloriously obfuscated and has a massive compression advantage.

Genius!

By: antimatter15

antimatter15 — Tue, 06 May 2008 00:07:37 +0000

I actually did this last week. Instead, I stored 3 ascii values per-pixel. Too bad this won’t work cross-domain.

By: alexeiwhite

alexeiwhite — Mon, 05 May 2008 23:36:24 +0000

I did some work with this a while back. I was exploring using LZ77 to do the same thing. I was doing it in JS and also using Flash. Here is my post:
http://blogs.nitobi.com/alexei/?p=166

and my demo:
http://blogs.nitobi.com/alexei/demos/compression/index.htm

By: p01

p01 — Mon, 05 May 2008 20:56:01 +0000

I like this kind of abuse of one technique/format to do something it was not intended for.

By: rhymeswithseven

rhymeswithseven — Mon, 05 May 2008 18:38:04 +0000

Now I can finally use flickr as a code repository!

By: tj111

tj111 — Mon, 05 May 2008 18:08:14 +0000

mind…blown…

By: Andrew Clarke

Andrew Clarke — Mon, 05 May 2008 17:58:41 +0000

And our computers come one step closer to experiencing a snow crash. :)

By: mdmadph

mdmadph — Mon, 05 May 2008 16:24:57 +0000

Actually, if your server still doesn’t support GZIP compression (hint hint: Domino), this is a pretty neat idea.

By: jdalton

jdalton — Mon, 05 May 2008 16:08:02 +0000

very cool idea though :)

By: jdalton

jdalton — Mon, 05 May 2008 16:05:49 +0000

Standard gzip of Prototype.js (1.6.0.2) is 28.2kb;
If you remove whitespace and shrink variables and gzip the size is 20.7kb.

-JDD

By: JeromeLapointe

JeromeLapointe — Mon, 05 May 2008 16:01:53 +0000

I guess if you have really huge XHR requests and wanted them compressed you could just use images instead…
Still kind of insane.

By: SteveBrewer

SteveBrewer — Mon, 05 May 2008 15:50:01 +0000

So, how does this compare to standard GZIP compression?

By: Schill

Schill — Mon, 05 May 2008 15:32:24 +0000

He’s a madman, a madman I tell you! ;) Interesting ideas, and fun stuff.