© 2011 Jan Wolter
Long, long ago I took a trip with the Sierra Club to New Zealand. When the trip ended the folks on the tour exchanged addresses and agreed to send each other some of the better pictures we took. (That's postal mailing addresses and pictures taken on film - this was long, long ago, remember?)
When I got home Texas and looked at my pictures, I was struck by how unconnected Texas and New Zealand were in my head. I'd gotten into an airplane in Houston, been rattled around for a long time, and appeared in Auckland with no real sense of the connection between the places.
And then, there was the incomprehensible fact that when I was in New Zealand, the direction of up had been entirely different than it was now. When I sat in Texas looking at a picture of New Zealand, I wasn't actually holding it right side up, because "up" in New Zealand is not the same as "up" in Texas.
So I got interested in figuring out how to turn pictures right side up. I invented a simple little diagram that could be drawn on the back of a picture, that would instruct you how to turn the picture into its correct orientation. Of course, the diagram would have to be different depending on where you are, but I knew the addresses of all the people I was going to be mailing New Zealand pictures too, so that was OK. I spent several days deriving the formulas I needed to generate the diagrams, and then hand drew them on the back of some of the pictures I sent out to the other Sierra Club hikers.
Naturally, I never saw any of those people again, and never found out what, if anything, they thought about my strange right side up diagrams.
So recently I happened to think about this again. I thought it might be something that would be of greater interest in the modern world. Geographic data is much more available. Many people carry around devices that track their latitude and longitude and can display pictures, Many images are geotagged, so you can tell where they were taken. I might be able to do something with this old idea.
Anyway, the first step was to reconstruct my original gadget, from the very fragmentary notes I had kept. I turned out I didn't need to redo my mathematical derivations. The formulas I needed could now be googled up seconds. Then I whipped up this little demo page so I could test my formulas and then prettied it up a bit to be able to show it to people.
What'll I do with this? Maybe nothing. I never actually met anyone who was as intrigued by this as I am. But I find the fact the direction of up in New York and Los Angelos differ by 35 degrees interesting.
I'm entertaining the notion of doing a smart phone app. The phone knows the viewer's latitude and longitude, knows where north is, knows at what orientation it is being held, and, if the picture is geotagged, knows where it was taken. So it could prompt you through a short series of movements until you have your picture held rightside up. If the picture's not geocoded, it could ask the person to enter the name of the city where it was taken, and get latitude and longitude from Google Maps.
But is this worth doing? I dunno.