I think it’s somewhat ridiculous that ArcGIS Explorer has the ability to add geotagged photos to the map, but ArcGIS Desktop doesn’t have a built-in means of recognizing geotagged photos. ArcCatalog already examines JPGs it finds for additional information in the case that the JPG is a spatially-aware aerial photo or a rectified map. Even a tool for creating a feature class out of geotagged photos would be great.(...)
Read the rest of Script: Geotagged Photos to GIS on my blog.

© John Reiser for new jersey geographer, 2010. | Permalink | 8 comments | Add to del.icio.us
Post tags: ArcGIS, geotagging, National Guard, python, scripting, SDSFIE

We recently conducted field work at the installation in Woodstown, NJ and I took along my Nikon Coolpix p6000 – with integrated GPS. Since I’ve gotten the camera, I’ve been taking plenty of pictures with it and have been pleased with the results. The pictures are of a great quality and the GPS coordinates are usually in the 1-10m range. I took about 150 pictures while the students were collecting data. Using my mobile office, I downloaded the photos into iPhoto so we could discuss the work being done. I exported the pictures from iPhoto using the Export functionality and saved them to our workgroup server.

"Rounded" and raw positions of geocoded photos.

This past week I’ve been working on a Python script* to take a directory of geotagged photographs and produce a point shapefile with the location of each picture and a path link back to the source photograph. I tested the script out on my Woodstown pictures and was conflicted: I was happy the script was doing what I wanted, but I was very disappointed with the results. It seems like  the geotagged photo points were all snapped to some imaginary grid. In fact, they were! iPhoto’s export function apparently rounds the seconds value (of degrees, minutes, seconds of latitude or longitude) to the nearest whole number. In doing so, it essentially snaps all of the coordinates to a grid with a spacing of 1 second, or around 100 feet. This clearly is a problem, as the most GPS units today are much more precise. The image at left demonstrates the difference between photos exported from iPhoto and the original images from the camera. Green squares represent the point shapefile based on the exported-from-iPhoto images and the blue circles represent the unaltered images. Except for two or so misplaced points, the blue circles accurately represent my position when taking the photograph within 15 feet.

Measuring the distance.

Measuring the distances between the rounded points clearly shows that the location information is improperly exported from iPhoto and the coordinates are being rounded. iPhoto does not by default include GPS Exif tags in exported images, presumably to preserve privacy. Regardless, if the “Export Location Information” checkbox is checked, why should iPhoto even touch the GPS info? I would think it should pass the Exif tags along without molestation.

I really hope that this is a bug on Apple’s part and that they don’t assume that integer seconds ought to be enough for anybody. Until they do fix the bug, we won’t be able to edit our photos using iPhoto and retain accurate coordinates.

* I intended to release the script this weekend, but realized that I did not include any documentation in the ArcToolbox file. Once I add some documentation to the tool, I’ll put the script online and add links to this post.

© John Reiser for new jersey geographer, 2010. | Permalink | 4 comments | Add to del.icio.us
Post tags: Apple, geotagging, iPhoto, National Guard, SDSFIE

Nipper Building, Camden

I’ve been organizing my digital photography library and posting some of my better pictures to flickr. The “Urban Design” collection highlights pictures that illustrate important urban design principles. I plan on using these photos for the future planning classes at Rowan, but you’re welcome to use them too, as I’ve released them under a CC BY-NC-SA license.

Oh, and many of the photographs have been geotagged, either manually or through GPS records. I’ll be adding older photographs when I get time and new photos as I take them.

© John Reiser for new jersey geographer, 2010. | Permalink | No comment | Add to del.icio.us
Post tags: geotagging, photography, urban design

Alcyon Lake

Brought my Blackberry with me on a bike ride around Glassboro and Pitman. I used beGPS One, a Blackberry GPS logging application to record my location every 30 seconds as an NMEA sentence. I then used GPSBabel to covert the file to KML format. You can view the KML of my route here. I also took the geotagged picture of Alcyon Lake at right. Finally, tweets during the trip are also geotagged.

Most of the information we deal with daily (or in this case, generate) has some geospatial component. Why not explicitly recognize the route I took or the places I photographed? Sure, some will feel that geotagging could be abused, but both Twitter and Flickr require you to explicitly allow geotagged information to be shown to other users. Facebook strips out geotagged information from uploaded photos. If there’s no real privacy concerns, you should share your pictures and tweets tagged with geographic coordinates.

© John Reiser for new jersey geographer, 2010. | Permalink | No comment | Add to del.icio.us
Post tags: Flickr, geotagging, gps, Twitter

There probably won’t be many updates to NJ Geo and NJ State Atlas until I come back up next week.

© John Reiser for new jersey geographer, 2009. | Permalink | No comment | Add to del.icio.us
Post tags: Flickr, Florida, geotagging, Google Latitude, Southwest Florida, Travel