Saturday, July 10, 2010

A Lesson in Degradation

Image and video hosting by TinyPic

The Gimp doesn't rotate images too cleanly in indexed colour mode.

10 frames below:

Image and video hosting by TinyPic

If you're using Firefox get yourself an image zoom addon and blow it up and then stare at it for 30 seconds and then look at someone you love and then kill them to spare them from the bugs crawling under their skin.

12 comments:

Andrew said...

I'm surprised it will do it at all. Most effects require full color. What you do is convert the image to RGB while you work with it and then when it's time to save go back to indexed.

Substance McGravitas said...

I'd ordinarily rotate in Quartz Composer and build a GIF out of exported frames, but the spikiness was interesting.

mikey said...

Why doesn't your cool mac graphics card take care of that with anti-aliasing in hardware?

Substance McGravitas said...

Any explanation I have for that'd be talking out of my ass, but I'd be impressed if you could rotate 36 frames of this on another system using the GIMP on a two colour GIF and not get the same result. I'd be surprised if Photoshop did it in a pristine fashion.

mikey said...

I think you're right. But most modern dedicated graphics chips do like a 4x supersample and render that down. One would have thought that would keep all that spurious noise from taking hold...

Substance McGravitas said...

What you do is convert the image to RGB while you work with it and then when it's time to save go back to indexed

After I got interested in the spikes I duplicated layers and rotated those ten degrees: I'll bet it'd look fine if I just duplicated layer one and rotated it ten, twenty, thirty degrees and so forth.

Ass-talking-out-of time: in a two colour picture any rotation algorithm is gonna have to decide on whether a pixel is on or off, and when you're dealing with curves you'll inevitably wind up with a pixel that should only be 40% on, therefore I imagine Photoshop would fuck this up too.

Quartz Composer produces a large and beautiful screensaver that produces the skin-crawling effect that this generates quite nicely indeed.

ifthethunderdontgetya™³²®© said...

I remember when I could write spaghetti BASIC on an Apple II, and be considered a tech nerd.

DAMN YOU ALL TO HELL!
~

mikey said...

Why, it's The Time Tunnel™!!

Andrew said...

Quartz Composer will almost certainly use your GPU. GIMP does not (yet) use GPU for anything, because using GPU in photo editing programs (or web browsers, etc.) is retarded. I personally view it as a gimmick that Photoshop CS5 does that.

No, but seriously, GIMP has a new graphics backend that might be able to take "accelerated" paths for some operations similar to the way your operating system's graphics system does.

Andrew said...

Oh, and anything that goes through the GPU will be converted to bit-depth color, probably transparently if Photoshop/Quartz Composer will let you do it at all. When you open a GIF it's probably converted into a 24/32 bit texture.

GPUs have no sense of indexed colors.

Smut Clyde said...

Some people cannot be trusted with the Motion Afterimage Effect.
I have have a mind to upload some animated gifs that use the Benham-Fechner effect to generate illusory colours. There is flicker.

Another Kiwi said...

Top one has fractal edges, I;'m telling ya.