How to convert size, when i have MPix and resolution?

[raku]

Hello all, I have one question. I need to know how to convert the sizes this way:

Let's say, that I have a picture, with that resolution: 2870 x 2777 (7.97MPix).

How can I know what width and height (in pixels) it will have on 1 Mpix, or 2.5 MPix? Has somebody an idea?

Thanks in advance,

raku

 

[Robin Usagani]

2870 X . 2777X = 1 e 6

Solve X

2870 X . 2777X = 2.5 e 6

Solve X


Then just use multiply 2870 by X

 

[480sparky]

2870 X . 2777X = 1 e 6

Solve X

2870 X . 2777X = 2.5 e 6

Solve X


Then just use multiply 2870 by X

I doubt it's that simple. Image files contain more than just pixel data.

I tried the pixel count idea, and reduced a 91.2 kB image 50%. The result was a 76.9 kB file.

 

[Robin Usagani]

OP never mentioned about file size. All OP said was Megapixel. It would have been simpler if OP kept the crop ratio to 2:3. You confused MPix (mega pixel i guess) to MB sparky.

 

[The_Traveler]

the size of a file is dependent on the original dimensions in pixels and, if any, the amount of compression with which it is saved.
So you can save a file with greater compression and the filesize will be smaller even though the pixel dimension stays the same.

 

[raku]

Guys, I need only the new size in pixels. I have the big size, as mentioned in first post. I have it's width x height and megapixels. I have also Megapixels of the "new" size, which I want to get the size (width x height). I don't care about the quality, cause I don't provide the photos : ). I have to only know the exact size. So, do you know the formula?

 

[480sparky]

1 MP image size = (1,000,000 / Original MP image size) * Original MP image size

 

[raku]

@480sparky
IMO, it still says me nothing. How should I use it to achieve my goal?

 

[480sparky]

@480sparky
IMO, it still says me nothing. How should I use it to achieve my goal?

You want a formula, and you get a formula. Now you can't figure it out?

Replace the Original MP number you have and insert it into the forumula. Then calculate for the result.

 

[480sparky]

Step by step instructions:

Multiply your Original image pixel dimension together (width by height).

Divide 1,000,000 by that number.

Multiply your Original image pixel dimensions by the result.