Re: Calculating Scan Size

From: Dave Soemarko ^lt;>
Date: 02/20/04-01:11:09 PM Z
Message-id: <001c01c3f7e5$4ce8ea10$9729fea9@W>

You can only get an approximation.

First, the number of pixels to store you image is (width * dpi) * (height *
dpi) = num pixels

Each pixel has 3 colors (for RGB file), so it is 3 * num pixels; For CMYK
file, it is 4 colors per pixel, so it is 4 * num pixels.

If the bit depth is 8-bit, since 8 bits is one byte, you file size would be
approximately the number calculated above. If the bit depth is 12-bit, it
will take 2 bytes for each pixel, so the number would be 2 * the above.

But then for an image, the data stored is not just the image data, there are
some other information (needed in programming and data handling such as data
type, version number, dates, etc.), so the number calculated above is only

Finally, each file system (FAT, NTFS, etc.) stores file differently, so the
number would be rounded differently.

But the calculation above is approximate, it should allow you to make pretty
good estimates.

Dave S

----- Original Message -----
From: "Sandy King" <>
To: <>
Sent: Friday, February 20, 2004 1:41 PM
Subject: Calculating Scan Size

> I know there must be a fairly simple way to figure out the total size
> of a file in mb based on scan resolution and size in inches but when
> I do the calcuation the way I think it should work it never agrees
> with the size of the actual scan.
> So how is the calculation made?
> Sandy King
Received on Fri Feb 20 13:11:31 2004

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