Apr 08
2
Number-Crunching
Posted by Stephen2
Tags: challenge, computer, photography
We visited the Grand Canyon over a year ago and took lots of photos (of course). I dealt with all of them last year, tagging, cataloging, printing, uploading and archiving. All except one small set: a panorama composite of 130 individual pictures. I’d started to do something with it way back then, but it was just too much so I put it aside. And there it sat, moldering away on the hard drive ever since.
Anyway, I have a friend’s computer to set up while he’s away on vacation. Seeing as setting up computers involves a lot of sitting around and waiting, I figured I could do the Grand Canyon panorama at the same time. That would also involve a lot of sitting around and waiting, so I thought I could work on one while I waited for the other, and vice versa.
The problem with this photo is memory limitations. The original photos take up about half a gigabyte. They get morphed to fit each other, and the intermediate images take up about six gigabytes. Then those images get blended into one, and the resulting (final) picture is about two gigabytes, about 500 megapixels.
My computer only has one gigabyte of memory.
The software didn’t like that. First of all, I had to figure out how to set things up so the software balanced disk and RAM in the most optimum way, using as much RAM as possible but not too much. Too much and the program would exceed the physical memory capacity and crash. Too little and the hard drive would churn away and it would take twenty hours to get anything done.
Adding memory to the computer would help a little, but wouldn’t solve the problem altogether. At most the PC can use three gigabytes with a 32-bit operating system. That’s still not enough to efficiently manage six gigs of images. In fact, I ended up processing the image in eighths. Each section needed about five gig to process. I shudder to think what’d be needed to do the whole thing at once.
So I did a little research to see what it would take to go to a 64-bit operating system. Current hardware technology allows up to 128 gigabytes of RAM. Surely that would be enough. But even if I had the megabucks to afford such a system (and I don’t), there are all sorts of compatibility issues that make it a pain to use that kind of computer for anything else remotely interesting, like games. Thus, it seems like I’ll have to wait for whatever follows Vista in Microsoft’s pantheon, and hope the whole software industry has caught up by then.
Unfortunately I can’t find the justification for a new computer, much as I’d like one. Whatever I get now still won’t be enough to efficiently manage such mammoth tasks. So I’ll wait. What I have now is perfectly adequate for 99% of my needs.
To give you an idea of scale, the picture at the top represents about half of the final image, but at a substantially reduced resolution. This lower photo of some cabins is an extract from the final image, at full resolution. It represents an area about three pixels wide in the top image.
