Since I’m starting with photos that are already timestamped, I want to be able to look up their timestamps in some sort of GPS database to see whether there’s a recorded time/location event near that time. Unfortunately, my initial perusal of a couple of geo-extensions to well known databases (SpatialLIte, PostGIS), show a generous helping of geometry-oriented query capabilities but no obvious time-query capabilities.

It could be that time-indexing is so simple compared with spatial indexing that what I’m looking for is just swamped in the documentation, or it could be that I’ll have to dig some more.

In a perfect world, this would be a relatively simple matter of looking up each photo’s creation date and time, finding that date and time in my years of GPS logs, and associating my GPS location for that date and time with the photo.

The world isn’t perfect. I took a lot of photos before I got a GPS device. Sometimes the device’s batteries give out or I forget to turn it on. There may be time zone and daylight-savings issues that make nonsense of the date-and-time link between the photo and the location, and I need to find and fix them.

Even if I manage to bring perfection to my existing data sets, I had better design a smooth-enough workflow for my future photos that I’ll actually keep up, and of course I’ll need to correct future mistakes and omissions.

Further, tagging the photos really becomes useful if I put them on maps, so I need a tool to make located map icons that point to the photos. I already tag my photos with broad categories, and I’d like to be able to vary the icon according to the category, or to sort the categories into separate map layers.

These are the basic goals. I’ll be blogging more as I design and build this thing.