FORUMS: list search recent posts

Why does an A0 sized image in Photoshop take up 2 gigabytes?

COW Forums : Adobe Photoshop

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
DanielHaskett
Why does an A0 sized image in Photoshop take up 2 gigabytes?
on May 22, 2005 at 3:03:35 pm

Hi

Ive just made a canvas A0 size and even without any images on it, it takes up 2 gigabytes, do you know why this, surely it shouldnt be the case? It is 300 dpi, would this be why? Any help would be greatly appreciated!

Thanks

Dan


Return to posts index

Skacey
Re: Why does an A0 sized image in Photoshop take up 2 gigabytes?
on May 22, 2005 at 10:14:59 pm

Photoshop is Raster based - the image size is constant weather it has anything on it or not.

In doing the math it seems that you are using 300 pixels per cm not dpi (which is per inch).

You have created a grid of pixels that is 300 pixels per cm times the size of your document.

Each pixel is either three bytes (RGB) or four bytes (CMYK)

Each square cm is 300 pixels x 300 pixels or 90,000 pixels

90,000 pixels times three bytes is 270,000 bytes or a bit more than a quarter of a Megabyte per cm.

A0 is 118.9 cm x 84.1 cm or 10070.83 square cm.

10,000 sqcm times 263k per sqcm is 2.6 gig.


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]