Posts Tagged ‘geocoding’

GeoURL Service

November 16, 2009

GeoURL

I found that Geotagging my WordPress blog posts has some utility even before WordPress release features that use the information.

GeoURL has a directory of goecoded web sites (pages?). GeoURL describes itself as

… a location-to-URL reverse directory. This will allow you to find URLs by their proximity to a given location. Find your neighbor’s blog, perhaps, or the web page of the restaurants near you. GeoURL is listing 4,896,702 sites.

It has a tool to add a geotagged web page to their directory and then list web sites that are located nearby. I think the reasoning is a bit weak: there are better ways of locating restaurants aren’t there? It seems like a solution running around seeking a problem to solve. But that’s okay – many things started out like that.

So I tried introducing my first geotagged WordPress post to the service to see what it would find.


You can click on any of the thumbnails above to see a full-sized picture.

  1. The “ping form” for GeoURL is at http://geourl.org/ping/. You only need to add the URL of the web page that has been geotagged.
  2. Press “Submit” and wait.
  3. If everything goes fine you’ll see this. You can click on “see your neighbors” and see:
  4. This list of sites that GeoURL thinks are close to me. The way they state Bangkok addresses is strange. That’s probably for the same reasons that Jeff Friedl’s Reverse Geocoding for pictures in Lightroom is so problematic – inconsistent address formats around the world.

You can check the results by clicking


GeoURL
That was a good exercise but it is of limited use. I will be interested to try the tools that WordPress introduces to support geotagged web pages.

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Geotagging My Posts

November 14, 2009

I just signed up for a new WordPress feature that lets me geotag my blog posts and comments.

I’m a fan of geotagging all the pictures I take and even trying to geotag other interesting pictures I find so this is a natural extension.

I have updated my user profile on WordPress to include the approximate location of my apartment in the Din Deang district of Bangkok. The Thai word “ชานเมือง” below is “Chanmuang” – a road close to the apartment. It’s not the mailing address but it is close enough.

My WordPress Location

My WordPress Location

I can disable that location being stored for each post. That’s most use for somebody posting from a mobile device. I am old-fashioned and generally post from my computer at home.

I don’t think there is anything to prevent me from lying about my location.

When you edit your user page WordPress can try to detect your location automatically. It failed in my case even though I responded Yes to a request from Firefox to allow the request.

My little Feedjit widget is good at locating my location-based on my IP Address (at least to the granularity of “Bangkok, Thailand”).

I do not see any concern about revealing the approximate location on my apartment on my photos or my blog posts. I live in a large apartment block guarded by aggressive Thai security professionals.

Apartment SecurityIf anybody takes exception to one of my posts then they won’t be able to get near me. I am usually cautious about privacy. If I lived in a single family home I would be more reticent.

WordPress says that the geocoding is not human-readable yet. I think they are hoping that lots of their bloggers will register their locations. Then they’ll be able to launch some more interesting services as they explain on their help page here.

I guess they’ll only add geocoding to posts made after I enabled it. This will be the first one. I looked at the page source to find out what all this talk about

Geotagged posts getting marked up with the geo microformat, geo.position and ICBM meta tags, and GeoRSS and W3C geodata in feeds. All of this stuff is “machine readable”, not “human readable”; it’s hidden from view.

entailed. I found two new tags at the very end of the header:

<meta name='geo.position' content='13.769588;100.569959' />
<meta name='ICBM' content='13.769588, 100.569959' />

I can’t keep up with all these acronyms. I found out that the ICBM tag isn’t directly related to Intercontinental Ballistic Missiles but is a reference to the GeoURL service. However, historically there is a connection: see here.

If I get people from Flickr or Nikon showing up outside the apartment because I’ve said bad things about them I will only have myself to blame.

Bangkok Reverse Geoencoding Challenges

November 6, 2009

As I’ve mentioned before, e.g. here I like to geoencode all my pictures with the latitude and longitude where the picture was taken. I also like to use that information to fill in the “location” fields in the photo’s IPTC information with the location in English. the latter process is called Reverse Geocoding.

I used Jeff Friedl’s excellent GPS Plugin for Lightroom for both tasks. Recently though I have been unable to reverse geocode many of my photos taken in Bangkok. Instead I get an error dialog box like this:

Lightroom Geocode Internal Error

Lightroom Geocode Internal Error

It does not happen for all locations. I reported the issue to Jeff and sent him a log file. I looked at the log file: Jeff showed great foresight in making his plugin write extensive logging information. It did not help me understand the error but it did give me an insight on how complex the reverse geocoding process is.

In the case of this test photo taken at +13° 44′ 12.15N, +100° 33′ 39.13W :

Geocoding Test Photo

Geocoding Test Photo - Click for a Larger Picture

Google returns eight choices for the address:

  1. “ถนนสุขุมวิท, Khlong Tan Nuea, Vadhana, Bangkok 10110, Thailand” (Sukhumvit Road)
  2. “อโศก, Khlong Tan Nuea, Vadhana, Bangkok 10110, Thailand” (Asok)
  3. “Asok BTS Station, Khlong Tan Nuea, Vadhana, Bangkok 10110, Thailand”
  4. “Asok Station, Khlong Tan Nuea, Vadhana, Bangkok 10110, Thailand”
  5. “แยกสุขุมวิท-อโศก, Khlong Tan Nuea, Vadhana, Bangkok 10110, Thailand” (Sukhumvit & Asok)
  6. “สุขุมวิท ซอย 20, Khlong Tan Nuea, Vadhana, Bangkok 10110, Thailand” (Sukhumvit Soi 20)
  7. “Vadhana, Khlong Tan Nuea, Vadhana, Bangkok, Thailand”
  8. “Khlong Tan Nuea, Vadhana, Bangkok, Thailand”

Some parts of the address are in Thai.

Jeff has to parse them into four fields that IPTC allows:

  1. Location
  2. City
  3. State / province
  4. Country

Bangkok is both a city and a state. It is divided into fifty districts (khet – เขต). Each khet is made up of a number of neighbourhoods (khwaeng – แขวง).

That terminology is unique to Bangkok. The equivalent term in other provinces is amphoe – อำเภอ and tambon – ตำบล.

When it works Jeff’s plugin has been allocating the fields thus:

  • Location : blank
  • City : Khlong Tan Heua (the khwaeng)
  • State : Bangkok
  • Country : Thailand

I can live with that but I’d prefer

  • Location : Asok BTS Station
  • City : Vadhana (the khet)

That’s choice #3. But I cannot expect Jeff to make a special case of Bangkok addresses and for all I know the information returned by Google may not be consistent for all addresses in Bangkok.

I’ll update this post with comments when Jeff posts an update to the plugin.

Incidentally, I hope Adobe retain Jeff on a consulting contract to ensure that his plugins work with Lightroom 3. They could also use his help in making the plugin architecture more flexible and less restrictive. For example, the way he has to maintain “Shadow GPS Data” causes many users a lot of frustration.

A Better Idea

September 2, 2009

Last night I prepared a long blog post explaining the complicated process I developed for getting tracklog information into EveryTrail from my geocoded photographs.

After writing it I had a better idea which I tested this morning. It worked well. I will trash the old post and document the simpler process.