Set which contains every possible image..

[Tglad]

we could go through every possible combination of images for a 640x480 256 color image relatively quickly.

that's 256^(640*480) which at 60 fps would take 10^307181 times the known age of the universe

[taurus]

that's 256^(640*480) which at 60 fps would take 10^307181 times the known age of the universe

 

[puntopunto]

  If we wrote something that went through all of the possible screens, we could go through every possible combination of images for a 640x480 256 color image relatively quickly.

  At 60 frames a second, an hour a day, it would take ~364.09 days to watch every conceivable permutation.

Certainly far from correct.

that's 256^(640*480) which at 60 fps would take 10^307181 times the known age of the universe

Correct

It seems that "a reasonable notion about possibilities" often don't exist. So let do some calculations:
Take a really tiny screen, a screen of 2x2 pixels and 256 colours. How many pictures can you make. That is 256x256x256x256=
1887442560 pictures. Now how many pictures can you see in 364.09 days at a rate of 60 frames a second: 60x60x60x24x364.09=
4294967296 . Dividing gives 4294967296 /1887442560=2.27555. So even to see all possible pictures on that tiny,tiny screen takes more then 2 years.
If we go on to a 3x3 pixel screen and do the same calculations then you see that you need already more then 1000 000 000 000 years.
The correct number, about 10^307181 years, for a screen 640x480 pixels is beyond every imagination. Even if we imagine 10 000 000 000 people on our planet and that there are 10 000 000 000 'earth planets' and they all are watching during 10 000 000 000 years, even then they only have seen 0, and then 307181-30 zeros followed by one 1, part of all possible screens. That is to say the best imagination I can give:"all those people, during all that time has seen nothing, nichts, rien, nada, niente" from all the possibiliies.


 

 

 

[matsoljare]

A two dimensional equivalent of the De Brujin sequence would be a challenge to come up with....

http://en.wikipedia.org/wiki/De_Bruijn_sequence

[quick-dudley]

A two dimensional equivalent of the De Brujin sequence would be a challenge to come up with....

http://en.wikipedia.org/wiki/De_Bruijn_sequence

You mean a De Brujin torus?
http://en.wikipedia.org/wiki/De_Bruijn_torus

Some have been found but it's not known whether one exists for every set of "lengths"

[M Benesi]

  Whoops.