From black to white via every colour inbetween, full screen.

October 30, 2006 8:48 AM

I want to generate a full-screen traversal of the entirety of RGB colour space. This is to be played back on a Windows computer.

The display machine is Windows. It has Firefox, IE, and the Microsoft office suite. It has Quicktime, but not Quicktime Pro. I do not have administrator rights on this machine, but could probably arrange to have free software installed on it. Pay software is out.

The tools I have at my disposal are: Linux computers with complete ImageMagick tools, reasonable programming skills, and libraries which can create Quicktime movies.

So far I have tried: Generating a series of one pixel bitmap images and converting to gif using convert and then using Firefox to show this gif expanded to fill most of the screen. This is OK but the indexing of the gif means that I run out of colours fairly fast. I have generated a quicktime movie which has the characteristics I want, but Quicktime needs to be upgraded to Pro to allow full screen viewing.

Is there some scripting language that I could use within PowerPoint? Some windows tool I don't know about? Or is there a way to do this in JavaScript?

posted by handee to Computers & Internet (7 answers total)

The *entirety* of RGB colour space? To what colour depth? Obviously the 8-bit GIF is out; 16-bit? 24-bit? 32-bit?

I'm assuming that you want the maximum gradation across all colours?
Do you want it to show one colour at a time, or all colours all at once (kind of like the colour-wheel palettes on a paint program)?

Should be possible with JS - create a basic page, and then use the script to change the background colour attributes one step at a time... this will give you 00-FF for each of R, G and B - i.e. 24-bit. Not sure how easy it would be to display full-screen either.
posted by Chunder at 9:03 AM on October 30, 2006

Photoshop. LAB mode
Gradient tool, black to white
A channel: draw left-to-right
B channel: draw top-to-bottom
View all channels
Convert to RGB.

Save image, copy to this computer.
posted by bonaldi at 9:37 AM on October 30, 2006

oh, hold on, I may have misunderstood: do you want the screen to be all one colour, then animate a run through all the spectrum?
posted by bonaldi at 9:39 AM on October 30, 2006

Response by poster: All one colour, then animate a run through the spectrum, showing one colour at a time. I thought I could do it in Javascript, with something along the lines of

for (i=0;i<2 55;i++) {br>
   for (j=0;j<2 55;j++) {br>
      for (k=0;k<2 55;k++) {br>
           setbackground(i,j,k);
           pause a bit
      }
   }
}

function setbackground(r,g,b) {
   colour_string="#"+hex(r)+hex(g)+hex(b);
   document.bgcolor(colour_string);
}

where hex is the obvious dec-hex converter, and the nested loops are called from an onLoad event. However, neither browser liked this trick. I got a downloadable background fade program to sort of work (it flicked through about 16 stages of grey), but it was way flickery, and as soon as I bumped up the number of transitions, the browsers stopped playing ball. ("A script on this page is causing mozilla to run slowly", yeah right. IE didn't even do the error message thing).
posted by handee at 10:03 AM on October 30, 2006

Response by poster: Damn pre tag handling. That looked fine in the preview pane.
posted by handee at 10:05 AM on October 30, 2006

Best answer: "I have generated a quicktime movie which has the characteristics I want, but Quicktime needs to be upgraded to Pro to allow full screen viewing."

If your only problem is full-screen viewing, VLC should work nicely. If you don't / can't install it, get the portable, self-contained version from PortableApps.
posted by niles at 10:07 AM on October 30, 2006

Even at 60fps, you will be displaying for 77 hours to show all of the possible combinations (256^3).

May I suggest a proper soundtrack?
posted by Diddly at 11:12 AM on October 30, 2006