I keep having online conversations with people who bemoan the fact that their computers have a spot of bother dealing with images with pixel counts of 10,000 * 8,000 or 13,000 * 18,000. They complain that the image scrolls slowly and they can't drag an image about but they obviously haven't the faintest idea of the implications of such an image.
One bright spark complained of the poor performance of an image having 13000 by 18000 pixels so I sat and did a little calculation which, I think, brings home just how much information is stored in such an image.
13000 * 18000 is 234000000. Multiply this by 4 for the bit depth of images stored in memory on the computer and you get 936000000 (936 million). Ok, A page of type in a programmere reference book runs out at about 88 characters by 36 lines. Thats 3168 characters per side and 6336 for a single sheet of paper.
On my bookshelves I have several books over 1000 pages in length and a thousand page book works out to be somewhere in the region of two inches thick. Our 6336 characters goes into 936000000 about 147727 times. This means a book with 148 thousand pages, 2 inches per thousand remember, is 24.6 feet thick.
Now I don't have many bookshelves in my house that are 25 feet long but if I had one I'd know that that was one fat book!
Even given the power of todays computers that's one huge chunk of info to mess around with. Why don't people understand that before they start whining about the scrolling performance of their image viewer application?
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