Simple combinatorics gone wrong

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Homework Help Overview

The discussion revolves around calculating the total number of possible photographs that can be taken with an 8 megapixel image, specifically with a resolution of 3264x2448 pixels, where each pixel can represent 16777216 different colors. Participants are exploring the combinatorial implications of pixel arrangements and color values.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • Participants discuss the factorial approach to calculating possibilities based on pixel positions and color values. There is a consideration of different image formats, such as JPG and GIF, and how they affect the number of possible combinations. Questions arise about defining what constitutes a valid photograph in terms of color diversity and the implications of using a limited color palette.

Discussion Status

The conversation is ongoing, with various interpretations of the problem being explored. Some participants have provided insights into the implications of different image formats on the calculations, while others question the simplicity of the proposed solutions. There is no explicit consensus, but several productive lines of inquiry are being pursued.

Contextual Notes

Participants are navigating assumptions about color representation in different formats and the potential for significant overlap in pixel combinations, particularly in lossy formats like JPEG. The discussion also touches on the need for clarity regarding the definition of a photograph in this context.

x2thay
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1. So consider an 8 megapixel picture (res: 3264x2448).
Now, it seems rather simple but I just can't figure out how to calculate the entire number of possible shots/photographs one can take within that resolution, assuming each pixel can have 16777216 different values/colors.




Homework Equations





3. The Attempt at a Solution
So I realize the number has to be absolutely monstruous, so here's what I've tried so far


(3264*2448)!*2^24

Meaning, the entire possible positions all the pixels can assume times all the different values each individual pixel can have.
 
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It seems your solution is correct for a JPG image but for a GIF you limited to 256 colors per image. Each color may range from 0 to 16million as a GIF uses an 8 bit value that indicates which color register from the color palette to use.

One problem I see is that you'll get shots all in one color or half one color half another...

Do you want to define what a photo is? like it must have a minimum of X colors per photo?

Next what about color changes that are imperceptibly small? Do you want to instead say that while RED can range from 0 to 255 in value we'll limit it down to a subset of {0, 16, 32, 48, 64 ... 255} in other words 64 color choices.
 
Last edited:
x2thay said:
1. So consider an 8 megapixel picture (res: 3264x2448).
Now, it seems rather simple but I just can't figure out how to calculate the entire number of possible shots/photographs one can take within that resolution, assuming each pixel can have 16777216 different values/colors.




Homework Equations





3. The Attempt at a Solution
So I realize the number has to be absolutely monstruous, so here's what I've tried so far


(3264*2448)!*2^24

Meaning, the entire possible positions all the pixels can assume times all the different values each individual pixel can have.

If you have 2^24 possible values of each pixel, then for two pixels you would have 2^24*2^24 possibilities, right? What about 3264*2448 pixels?
 
jedishrfu said:
It seems your solution is correct for a JPG image but for a GIF you limited to 256 colors per image. Each color may range from 0 to 16million as a GIF uses an 8 bit value that indicates which color register from the color palette to use.

One problem I see is that you'll get shots all in one color or half one color half another...

Do you want to define what a photo is? like it must have a minimum of X colors per photo?

Next what about color changes that are imperceptibly small? Do you want to instead say that while RED can range from 0 to 255 in value we'll limit it down to a subset of {0, 16, 32, 48, 64 ... 255} in other words 64 color choices.

No matter how insignificant the difference is, I meant to calculate e-v-e-r-y single possible matrix 3264x2448 arrangement, given that each entry can assume 2^24 different values. so yes, there will be an enormous amount of shots in which the only difference from the next, will be a single pixel.
 
Dick said:
If you have 2^24 possible values of each pixel, then for two pixels you would have 2^24*2^24 possibilities, right? What about 3264*2448 pixels?

So... (2^24)^(3264*2448) ? Basically 17M^8M? Are you sure that's correct? It seems too simple.
 
x2thay said:
So... (2^24)^(3264*2448) ? Basically 17M^8M? Are you sure that's correct? It seems too simple.

Yes, I'm sure. It's actually too simple for me to be wrong. It's (number of possibilities for each choice)^(number of choices).
 
x2thay said:
So... (2^24)^(3264*2448) ? Basically 17M^8M? Are you sure that's correct? It seems too simple.

What format? You didn't answer.

Since jpeg is a lossy format a lot of those combinations ought to evaluate to the same output. I could be wrong.
 
rollingstein said:
What format? You didn't answer.

Since jpeg is a lossy format a lot of those combinations ought to evaluate to the same output. I could be wrong.

I should have mentioned earlier, but I meant a bitmap format.
 
Okay, got it. The solution is a number whose log is 115 805 766.
Thanks, guys.
 

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