House Hunting with GPS

We’re house hunting. If you’ve been watching the financial news you know this might be the worst possible time to sell a house. However, it is also a great time to be buying. So, we’re house hunting.

The ready accessibility to the MLS for the counties around us makes it a lot easier. We can see what is for sale, how much it is listed for, square footage and all that. So, we’ve been using mlslistings.com to make a list of houses that we think we’re interested in and then, on the weekend, we drive out and do drive-bys of the places on our list. At the same time we drive around the various neighborhoods to get a feel for the community. When we got home, I was had a hard time associating the fliers we picked up with the location from which we got them. I figured this was an excellent justification to learn about geocoding.

I already have a Canon PowerShot Pro 1 camera, which will have to do until I pick up my Canon 5D. I needed a way to embed the latitude and longitude into the EXIF of the image. I was hoping my Garmin StreetPilot i3 would provide the lat/long information I needed but it can not. So, I purchased a Magellan eXplorist 210. I chose this particular device because it was the cheapest handheld GPS device with a display and a USB connection. For those wondering, the eXplorist 210 connects to Mac OS X and appears as a volume and is completely usable with Mac. So, now I have a way to track where I’ve been.

The trick then, is to use a track file from the GPS device to determine the exact lat/long where the photograph was taken by using the time of the photograph. The EXIF data in the photograph will have the time it was taken. The GPS log file will have a lat/long associated with that same time provided that it is on, logging and with the camera. There are a number of applications that might help us out. I only tried as many as was necessary to accomplish my intended goal. There might be others out there. Here are the applications that I tried.

HoudahGPS

This one did not work for me. No idea why. Might have been me, maybe it’s the software. It simply did not work.

LoadMyTracks

This works great for my purposes. Using LoadMyTrack’s Translate File from the File menu I translate the Magellan track.log file which is in a proprietary format to GPX which is an XML interchange format. I’ve never been able to get any of these applications to talk directly to the 210. Not sure why.

Next, I connect my camera to the PowerBook G4 and let iPhoto import them. While iPhoto is importing I’m wondering why iPhoto does not already support geocoding. Because iPhoto does not support geocoding, I have to export the images. So, I now have the pictures I want to geocode and the GPX file from which to get the geocode in a single directory on my desktop.

HoudahGeo

While HoudahGPS did not work for me, HoudahGeo works great. I used it twice and then paid the shareware fee. HoudahGeo first loads the photo images, then the GPX file. It then matches times to determine the lat/long of the photos. HoudahGeo then gives you the option of writing the data to the image files, importing the data and the photos to Google Earth, or exporting the photos to Flickr. I do all three. You can take a look at our house hunt here.

It is a lot of fun to associate the photos you take with the location they were taken. I think all of us have sorted through the family photos and wondered, where was this taken. Additionally, we wonder, who is that person. I’d like as much information as possible embedded in the image file itself so that, when you have the image file, you have the whole story. This is a fundamental reason that I think iPhoto sucks. iPhoto provides things like keywords and description fields but the information is not attached to the image file. It is put into a separate database. Lose that database file, you’ve lost whatever information was in there. IPTC Core picks up where EXIF leaves off providing metadata fields for keywords, descriptions, photographer, copyright, etc. All of this information is embedded into the image file so that any application that supports this metadata can, at a minimum, diplay it. iPhoto ought to be leading the way. It ought to already support geocoding, IPTC, and it should be using the image file as the storage medium for the information.

aloha

[posted with ecto]

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