How many possible images can be displayed on an 800x600 screen?

Question

I have a limited understanding of how display works, and apparently there are around 17million different colors that can currently be expressed in a pixel using RGB code. I've tried calculating this before but I seem to be doing something wrong, also, is it possible to express it on a computer screen? I don't think it could be an infinite amount, but I may be wrong. Anyone know the answer?

Please excuse my horrid wording

Answer 1

How many possible images can be displayed on an 800x600 screen?  480000 tiny (1 pixel) images!

> apparently there are around 17million different colors that can currently be expressed in a pixel

depends on color depth (bits per pixel), not resolution.

2 raised to the 24th is about 17 million, so a color depth of 24 will give you almost 17million colors.  Thats 3 bytes per pixel.

Answer 2

It sounds like you are asking how many different "pictures" can you create on a 800x600 screen with 17 million colors per pixel. The number isn't infinite but it is very large. An 800x600 screen will have 480,000 pixels. If I remember my match right the total number of combinations of colors and pixels would be

17million to the 480,000th power, which is a huge number.

Answer 3

With a color depth of 24 bits, you can have 2^24 or 16777216 different colors on a given pixel. 800*600 is 480000, so the total number of images is 16777216^480000, or 2^11520000. Since log(2,1000)=9.9658, 2^11520000 is roughly 10^3467865.55, or 1 followed by three million four hundred and sixty-seven thousand eight hundred and sixty-five zeroes. This number CAN be represented on your computer, but I don't know how to properly compute it in any programming language (Javascript maxes out at around 2^1024, which contains less than one ten thousandth the number of digits as the number you're talking about). Unfortunately, it can't really be properly compared to any physical quantity in our universe, because it is simply too big. If for example you typed out the number of cubic planck lengths in the Universe (the planck length being the shortest meaningful unit of distance, equal to a little over one trillion trillion trillionth of a meter) in size 10 Arial, it would be less than 20 inches long at 72 pixels per inch. The number we're talking about, written in the same font and size, would be more than five MILES long.

Answer 4

With a colour depth of 24 bits, you represent a "colour" with 3 bytes of 8 bits.  Each byte can take a value from 0 to 255.  This gives a total number of possible DIFFERENT colours to be 16,777,216. (Exactly).

(256 x 256 x 256)

A higher depth is useless (for US, humans), since the average person can distinguish just about 5,000,000 colours, and a trained eye (like a printer or a painter), 7 to 8M, or just about half of what a display can show! (Paint half the screen with FFFFFF (plain white), and the other with just FEFEFE (3 bits less): you will NOT see the difference.

Having depths of 32 bits is - for humans - a total waste of time.

Not the case for machines, though.  However, at that level, the problem of "noise" become an important factor in computation.