Thursday, March 29, 2007

Dear Ms/Mr GIS, Can you help me please?

Idea #2
Got a technical geo-question that you can't answer? Use the Blog to get your questions out to the WNCGIS community. Community members can respond via blog comments or by making a new posting. You may be surprised at the number of people who will empathize with your situation, help solve your problem, or who will appreciate your knowledge. We have numerous GIS educators in the group. Below is one of my technical issues. If you have any ideas please respond.

I would like to use cellphones as a data collection tool for a research team. The team will be documenting a variety of environmental conditions across western NC. To do this the cellphones must first have the capability to take photographs (most do). Most cellphones also contain some type of GPS and time function. With this, the researcher should be able to email a photo with a time stamp and GPS coordinate soon after the photo is taken.

Does anyone have any experience with or knowledge of how to extract the GPS coordinate and the time stamp with the photo image? If you have any answers or ideas please leave a comment, or post your answer to the blog.

THANKS, Neil

2 comments:

Leo Klausmann said...

I did some research on this issue and the only info I could find about extracting coordinates from jpegs is here: akuaku.org/archives/2003/05/gps_tagged_jpeg.shtml

Now, this person ends up saying that a program called metadata extractor can work with blogs, and it seems to work if you have some command line skillz, you can get it here:
http://renaud91.free.fr/MetaDataExtractor/

The little app mentioned at akuaka.org called photo studio actually does the trick. You load up a jpeg and look at its EXIF attributes. If I load up the photo of that cute Japanese girl that the guy talks about, there is a separate EXIF info tab with all the wonderful coordinates we need. I tried to do this with my own phone. I enabled GPS Location to be always on (as opposed to E911 only), went outside, waited a few minutes, and took some photos. I couldnt find any options to include coordinates on my Samsung phone and when I loaded the photo, there was no info tab with the GPS data. So at least we now have a lead on how to get the data out of a phone's jpeg, but now we need to find out how to make any model of phone actually write that GPS data with the jpeg.

David Abernathy said...

We are working on this on our end as well. We've got a JAVA class working on creating exactly what you're talking about, Leo -- they are creating a program that automatically sorts the JPEG data and extracts the EXIF info. But you're right -- the problem is getting that info into the JPEG to begin with. It could happen now but it seems that the wireless carriers see this as a profitable area and restrict access to the GPS information. I noticed that Verizon has a service called VZNavigator which, for a fee, lets you access your GPS information and maps. So one end-around at this point might be to take a picture and upload it to a website along with the lat/long. We'd then have to figure out a way to have that info entered into a database and converted to KML.