www.weisserth.net : Tag apple, everything about Apple

Geotagging images in Aperture 3 with Places

Mon, 19 Jul 2010 21:48:00 -0000

Using Aperture’s Places to geotag my images has been a much desired feature on my Aperture feature wish-list when I still used the old version. It turns out that using Places is not as straight forward as I expected it to be. Manually dragging pictures to the map works perfectly fine, but when adding GPS tracks and automating the process of placing the images, it’s hard to get an accurate result.

I’m using a popular GPS logger to record GPS data to geotag my pictures in Aperture. As I’ve had some trouble with the workflow of automating everything as much as possible, I’m sharing the results of my findings here with you.

The device I’m using is a Wintec WBT-202. I set it up to record a GPS location every five seconds. The device has a replaceable 1GB memory card to record data. It also can record waypoints by pressing a special button. The data format it uses has the filename extension .TES, a format Aperture cannot deal with. I’m converting it to GPX, a XML based format, using Wintec’s software that comes with the device.

When first trying to match the GPX data against my pictures the results were daunting as the automatic placement in Places got it all wrong. The most important detail in matching GPS recorded data against images taken is the time the camera uses and embeds as metadata into the images and the time the GPS logger stored for each location. It’s easy to set the camera time in the settings menu of every digital camera. The GPS logger does not have any option to set the time. It uses the time it retrieves from the GPS satellites.

Your first priority should be to set the time in your camera to your local time, taking daylight savings time into account if applicable. Look up the current time on the Internet (there’s plenty of services for that).

So, which time zone is the GPS logger using? It doesn’t really matter actually, at least when using the WBT-202. As the WBT-202 stores data in the TES format, we need to export the data to something Aperture can use anyway. When exporting from within the Wintec device software, you can set a timezone. Choose the right time zone. It’s probably easiest to think in offsets of GMT. Take daylight savings time into account.

You can open the generated GPX file in any text editor. You should be able to understand the structured XML. Notice that waypoints and locations are marked differently. You should check the timestamps saved with each location and validate that they match the timezone you intended to use.

After importing the generated GPX file into Aperture, Aperture will show the waypoints only. You can select to show the whole track, which you should do. Hover the mouse over the legs of the track and notice how Aperture messes up the recorded times. In my tries, Aperture never got it right, ignoring the correct time stamps. The solution is to tell Aperture which timezone you want it to use.

Setting the timezone using the geographical names of timezones did not work for me. Even after setting the right timezone, the legs of the track still showed the wrong times. This must be a bug in Aperture 3. It’s not difficult to find references to this buggy behaviour on other blogs if you use Google.

Again, it’s easier if you use GMT offsets at the bottom of the menu. That worked for me. Now the legs of my track showed the correct times.

We’re ready to tag the pictures now. Rather than relying on Aperture to take care of matching times and location, we choose a single picture we can place on a leg of the track ourselves with confidence that it’s placed correctly. This is important! When you drag that single picture across the legs of the tracks, you will notice the time offset Aperture displays. It’s the delta between the embedded time in the picture and the GPS data. As much care as we took to synchronize the GPS time to our camera time, there still is an offset. I’m not sure if it’s possible to get rid of this offset at all.

When you drop that single image on the right spot, Aperture will ask you if it should place the rest of the pictures of your project on the track. You can let Aperture do its work now. It will apply the same time offset to the other pictures as to the first one. I had to correct only a few pictures when it finished.

If you have a better way to deal with geotagging in Aperture, please let me know in the comments.

A short test drive of Valve's Steam on Mac OS X

Sat, 15 May 2010 16:19:00 -0000

Valve has released its games distribution platform Steam for Mac OS X recently. I downloaded it two days ago and gave it a short test drive on my MacBook Pro. Basically, most of what I expected from the platform worked. Some things, like payment and support are more than just shaky - in a negative sense. Also, at least on my Mac Steam crashes more often than what is tolerable.

I'm using a MacBook Pro 13'', 2.53GHz, 4GB RAM with Mac OS X Snow Leopard. Installing Steam was a breeze. After downloading a small DMG file and accepting Valve's usage terms the installer downloads the rest of the software. After starting it for the first time, a Steam user account must be created, much like in iTunes. I got up and running fast. I wanted to try two things: download and start Portal which is available for free for a limited time only and depending on how well that went, I also fancied buying Torchlight, an action RPG which is now also available for Mac and price reduced by 50%. Here are the things that bothered me most, in the order I noticed them:

There is no copy and paste within Steam. If you're using programs like Keepass or any other password manager from where you copy and paste passwords where you need them, then you're out of luck in Steam. I found this to be a major annoyance when setting up the Steam account and more importantly when paying using Paypal.
When downloading Portal, I noticed that the integrated download manager is not very smart. The download was aborted or halted a couple of times (due to the huge interest into this title). I expected the download manager to resume the download after some time, but that didn't happen. You have to check on it from time to time and resume the download manually. That was a bit inconvenient. Also, the download interface didn't update its status accordingly so that it was actually a bit confusing whether the download was halted or running. I noticed some of those problems again when downloading Torchlight.
Steam crashes quite often on my Mac. I haven't found any other Mac user with the same experience, but for me that happens quite a lot.
When purchasing Torchlight, I opted for Paypal payment. That didn't went smooth at all. After working through all steps of the purchase dialog, a new window opened up, redirecting to the Paypal site to complete the purchase. The redirection didn't work, instead the window showed the home screen of the Steam shop. I went back to the purchase dialog in the other window, repeating the process. This time, a new window opened up, taking me to the Paypal site. I completed the payment there. The purchase dialog in Steam then informed me, that the purchase was not completed, due to problems with my credit card (WTF?!). After waiting some time, I tried to repeat the last step of the payment process for this game. Steam then recognizes, that the game has already been bought. It then shows up in the list of available games, from where I could download it. See attached screen shots.

While waiting for the Paypal payment to be effective, I used the 'support' link from the help menu to find out about support options. It takes you to a web page that handles support issues for Steam. The site has a login form on the left side. Trying to use your existing Steam account to login there doesn't help much though. They don't tell you before you try, only after your login is not accepted will they display a hint that you need to create a separate account for the support. This is a very poor solution. I created an account for the support site. An activation email was supposed to be sent to my email address I specified. Without that activation mail, there is nothing you can do on the site. That email never arrived, even after having the support site resend it a couple of times. To sum up, I was unable to contact the Steam support at all. FAIL.
When playing games, it can happen that it's impossible to close the Steam client even after any game started from within is already closed. That seems to be a common problem, even on the Windows platform.

After playing around with Steam for a while, downloading and buying two games, my impression is that the overall quality of the service is not beyond beta status. The basic functionality is there but everything is still rough around the edges. In my opinion Steam on Mac is not in a state that should be released to the public. Once it's ready it's a nice platform for games distribution, especially if you own both a PC and a Mac (as you can get some games you already bought for PC on to your Mac without buying them again). However, I would still wait a bit until Valve fixes most of the rough corners.

By the way, Portal is great. So is Torchlight. You should get both while Portal is still free and Torchlight down to 50% of the normal price - well, if you're prepared to deal with the quality issues of Steam at the moment that is.