How to Calculate the size of a uncompressed image ?

All scanned images comprise of dots, in black and white scanning, which is the most used method in document scanning these dots represent Black or White (On or Off)

When scanning we use a term called DPI, what is DPI, it is Dots Per Inch. this means how many dots are used to represent the information on the paper.

Think of a A4 size page, A4 size page is 8.5 Inches wide and 11 inches tall. If you need to know more about page sizes you also can download one of our paper size chart from this web site.

In this sample page there are 8.5 x 200 Dots and each dot can be black or white. Also vertically there are 11 x 200 Dot Rows.
= 8.5 x 200 x 11 x 200 Dots in the whole page
= 3,740,000 Dots or BITS
=(3,740,000 / 8 ) => 467,500 Bytes
=(467,500 Bytes / 1024) => 456.54 Kbytes
=Half a Megabyte

just Imagine if you scan a A4 size document with 200 DPI the original file size of the image is 456 Kbytes. But in reality we compress these images to smaller files.

if you like to learn more about this you can visit the link to how compression is done and how much you can compress.