Question about megapixel conversion..

[domorek]

Hi guys,

Quick question. If i have a 3.5 Mpixel camera, provided i take the pics at the biggest resolution, what will be the measurements of the picture in pixels?(WidthxLength).
In other words, is there a rule by which you are able to calculate the pic size from the camera's max resolution?

Thanks in advance
K

:confused:

ps. 3.5 megapixel= 3.500.000 pixels...but how do you calculate the size from that? do you use the 3.2:2.4 ratio? if so, how?

[Ikinaa]

Mathematical solution :

the surface in mpix here is called s, the width of the pic is w, the height is h, the ratio is r

then w = r * h
s = h * w = r * h^2
h = sqrt(s/r) (square-root)
w = r * sqrt(s/r)
so if s = 3500000, and r = 1.5 (ratio of 3 to 2)
h = 1527
w = 2291


check : 1527 * 2291 = 3498357
ok ?

[Scottes]

3:2 is most common - almost always, really, for P&S cameras, etc.

To calculate, it's easy:
Width is 3 x square_root( Megapixels / 6 ), height is 2 x sqrt(MP/6)

So for your camera 3,500,000 / 6 = 583, 333. The square root of this is 764. So the width is 3 x 764 = 2291 pixels, and the height is 1,528 pixels.


Edit: Reading Ikinaa's post make me realize that my formula works for images with a 3:2 aspect ratio. His works regadless of aspect ratio since those formulas build it in.

[MTalley]

3:2 is most common - almost always, really, for P&S cameras, etc.


Uhm, no, if you check specs, most all P/S digicams have a 4:3 aspect ratio that matches the aspect ratio of most common computer screens - the most likely target for most folks.

With the exception of the Oly Evolt, most all DSLR's utilize the same 3:2 ratio as their film forebearers.

[Scottes]

Yeah, I'm too used to DSLRs I guess.

So, if 4:3
Width is 4 x square_root( Megapixels / 12 ), height is 3 x sqrt(MP/12)
So for 3.5MP, then 3,500,000 / 12 = 291,667. The square root of this is 540. So the width is 4 x 540 = 2160 pixels, and the height is 1,620 pixels.