“bad subifd directory” Replacing/removing bad SubIFD

Handling bad SubIFD entries in photos you want to geo tag / the problem

I just converted some of my RAW photos in RawTherapee and polished them in Photoshop CS. Of course I also wanted to GeoTag them (using GeoSetter) before putting the images in my archive. Fortunately, a GPS point was found in my trace for all photos. Unfortunately, I couldn’t write the Exif-GPS position due to a “bad subifd directory”. That’s what exiftool (which geosetter uses) tells me.

So – how to get the geo information into exif – or how to get the bad SubIFD directory out?

The solution:

In the end the issue was rather easy to solve:

1. copy your images to a linux machine (or vm or whatever)
2. copy all images to a directory “conv” AND in parallel to “conv2“
3. enter “conv2“
4. remove all exif information from the conv2 images by
   find ./*.jpg -exec exiftool -exif:all= {} \;
5. enter “conv1” & copy the exif information (except SubIFD) to the cleaned images in “conv2” by
   find ./*.jpg -exec exiftool -tagsfromfile {} -exif:all --subifd:all ../conv2/{}\;
6. you’re done.
7. (fire up geo setter and geo tag your photos)

Be happy!

Convert Mercurial repository to Git

I have converted yet another googlecode Mercurial repository to Git – and as it took me (again) a bit too much time, here is my recipe:

Prepare

Log into a Linux shell (Windows will hardly work – at least it didn’t work for me). If you don’t have some remote shell, download an Ubuntu VM and fire it up (you might need to install VirtualBox if you haven’t installed it already).

Check out your HG repo:

hg clone https://code.google.com/p/MyHgProject/

Check if you have to remap some author information:
hg log MyHgProject

If you want/have to remap, simple create an author map file
oldemail@example.com=Firstname Lastname

Convert

Get fast-export and convert your repo:
git clone git://repo.or.cz/fast-export.git
mkdir new_git_repo
cd new_git_repo
git init
/path/to/hg-fast-export.sh -A ../authormap -r /path/to/MyHgProject
git checkout HEAD

Push

Now change the source setting in your google code repository to git and push the local codebase:
git remote add origin https://code.google.com/p/MyHgRepo/
git push --all

At this point, your upload might fail with something like “error: RPC failed; result=35, HTTP code = 0″.
This can happen if your upload takes too long and this is a documented bug.
I simply solved this issue by pushig the git repo from a shell with a fast enough upload speed as my local connection obviously was too slow.

Wiki

Now you might realize that you have “lost” your complete wiki – don’t worry, it’s still there!
Switch back your repo setting to Mercurial and repeat the process for your wiki which you can usually find at https://code.google.com/p/yourProjectName/source/checkout?repo=wiki

That’s it. You should now be ready to use Git!

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Thanks to following sites hedonismbot, scrambled tofu

No more windows backup after uninstalling Acronis True Image Home 2011

I gave Acronis True Image Home 2010 and 2011 really quite several chances but it seems that either the product cannot reliably perform regular backups for my computer or I am just incomatible with it. Anyways – I finally wanted to draw a final stroke, get rid of Acronis True Image Home (ATIH), uninstall it and try Windows’ native Backup and Restore.

After unsintalling TIH I wanted to configure Windows’ backup and restore tool.
But – the according window just didn’t open!? Is TIH still bothering me AFTER I uninstalled it?

After quite some googling, I found one article in the Acronis Knowledge Base “14741: Acronis True Image Home 2011: Disabling “Integrate True Image into Windows” Does Not Work“. Unfortunately this only applies to an installed Version of TIH where Dis-Integrating TIH from windows backup does not work. – It’s quite a while since I tried it – but if I remember correctly, this didn’t work out for me. So another round at google was waiting for me.

Step 2

Step 4

Step 5

Step 7, 8

After quite some frustraiting searches on google, I finally found an post in the Acronis forum from September 2010(!) “14782: TIH 2011 uninstall wiped out my Windows 7 Backup & restore“. After scrolling over about 35 posts (including Acronis support, I finally found a posting of User Grant from Mi, 2011-02-23 22:28 who stated that he found the solution by chaning a registry entry. Well – I don’t want to keep you in suspense: It really worked out! As I don’t know how long this article will stay online in the official forum, I’ll try to redescribe it here (even though I hope that I never ever have to fix that again):

1. Open the registry editor (regedit.exe)
2. Search for the key {B98A2BEA-7D42-4558-8BD1-832F41BAC6FD} (Ctrl-F) and navigate to the sub-folder Instance/InitPropertyBag.
3. On the right hand side you can see a ResourceDLL entry pointing to a non existing TIH path – “great”. But you can’t change it – thanks to TIH. So let’s get back control:
4. Right-click on InitPropertyBag> properties (german: Berechtigungen) > Advanced (german: Erweitert)
5. open the owner tab (german: Besitzer) and change the owner to your own user.
6. Hit okay, and back to the Step 4 screen. give yourself full controll (german: Vollzugriff) and hit okay again to be back in the reg editor
7. Change ResourceDLL property to “%SystemRoot%\System32\sdcpl.dll“
8. Change the ResourceID to “14“.

Now Windows Backup should be available again and TIH is (hopefully!) fully uninstalled.

How to write useful error messages

Each programmer has to deal with error mesages in some way. Either we have to check our data (and possibly raise an error/exception) or we are using libraries and have to deal with error messages or exceptions that are raised in these libraries. The purpose of this post is to point out how meaningfull error messages can save you time. Either your own time (by avoiding answering support questions) or your own debugging time.

So how can an error message save or waste time? Imagine the situation where you try to open a file and all you get is an error. What do you do next? I guess you’ll probably check if you’re trying to open the correct path. Maybe you did, then you possibly check if the permissions are okay, if you’re trying to open a directory or a file, etc until you found the problem that is causing the error. Actually this can be quite some wasted time – why? Becasue you’re doing all the stuff that the system already checked. The system decided that one of the condidtions failed and exited. So – shouldn’t the system just TELL the exact reason? And even better: shouldn’t it also just tell you a possible solution? Well – actually I do not blame “the system” but the guy who write the line that threw the error without any further information. Everytime I get an absolutely uninformative error I think “was it really so damn hard to add one more line of code that just mentions WHAT went wrong?!”.

Assume the situation where you try to open a file with the path being configured in an external config.properties file.
I think the quality of an error message can be categorized in one of the three categories:

1. Reporting: The system just reports that there was an error.
   Example: IO Exception occured.
2. Informing: Same as 1, just with more information.
   Example:  IO Exception occured while opening file: <filename>, null=false, exists=true, is file=false, is directory=false, readable=false, writable=false
3. Supporting: same as 2 with additional information of how to solve the problem.
   Example: IO Exception occured while opening file: <filename>, null=false, exists=true, is file=false, is directory=true, readable=false, writable=false; Was the pat set correctly in config.properties?

In the past weeks I have seen very useful error messages in Google’s Android (“… Have you declared this activity in your AndroidManifest.xml?”) or in twitter4j (Displaying a shortURL to an FAQ page explaingin a very common error).
Bad examples are plain NullPointerExceptions when 3 parameters were checked, one of them was null and the according is just followed by a throw new NullPointerException so that you even did not recognize from the message WHICH parameter was null.

Conclusion: Please write robust code and please provide helpful and supportive error messages to the folks using your code!

Parse Error: There is a problem parsing the package / Beim Parsen des Pakets ist ein Problem aufgetreten

Just finished my first (real) Android App and wanted to deploy it in my phone (not just in the emulator).
So I sent an email to myself with the .apk attached as several tutorials said that you can just open it from your mail to install the app.
On the phone, I opened my mail app K9 and opened the .apk. But instead of installing I unfortunately just got

Beim Parsen des Pakets ist ein Problem aufgetreten.
(in english) Parse Error: There is a problem parsing the package.

even though the minSdkVersion was set correctly.

The solution was rather simple: Do NOT open the .apk in K9 directly but save it to the sdcard and open it via a filemanager like Astro.

Knowing: A Generic Data Analysis Application

We got another demo accepted:

Thomas Bernecker, Franz Graf, Hans-Peter Kriegel, Nepomuk Seiler, Christoph Türmer, Dieter Dill
To appear at 15th International Conference on Extending Database Technology (2012)
March 27-30, 2012, Berlin, Germany

Abstract:

Extracting knowledge from data is, in most cases, not restricted to the analysis itself but accompanied by preparation and post-processing steps. Handling data coming directly from the source, e.g. a sensor, often requires preconditioning like parsing and removing irrelevant information before data mining algorithms can be applied to analyze the data. Stand-alone data mining frameworks in general do not provide such components since they require a specified input data format. Furthermore, they are often restricted to the available algorithms or a rapid integration of new algorithms for the purpose of quick testing is not possible. To address this shortcoming, we present the data analysis framework Knowing, which is easily extendible with additional algorithms by using an OSGi compliant architecture. In this demonstration, we apply the Knowing framework to a medical monitoring system recording physical activity. We use the data of 3D accelerometers to detect activities and perform data mining techniques and motion detection to classify and evaluate the quality and amount of physical activities. In the presented use case, patients and physicians can analyze the daily activity processes and perform long term data analysis by using an aggregated view of the results of the data mining process. Developers can integrate and evaluate newly developed algorithms and methods for data mining on the recorded database.

BibTex

@INPROCEEDINGS{BerGraKriSeietal12,
  AUTHOR     = {T. Bernecker and F. Graf and H.-P. Kriegel and N. Seiler and C. Tuermer and D. Dill},
  TITLE      = {Knowing: A Generic Data Analysis Application},
  BOOKTITLE  = {Proceedings of the 15th International Conference on Extending Database Technology (EDBT), Berlin, Germany},
  YEAR       = {2012}
}

More informations will be published at the official publication site at the LMU.

SRTM Plugin for OpenStreetMap

One of the features of our TrafficMining Project at the LMU was to use additional attributes in routing queries. Standart routing queries usually just use time and distance for calculating the fastest/shortest routes. In order to have an additional attribute we decided to use evelation data as this might be an issue if you also want to take fuel cost into account or if you’re planning a bike tour (instead of crossing a hill, you might want to consider a longer tour that avoids crossing the hill).

The problem just was that data nodes from OpenStreetMap are defined mostly by id, latitude and longitude, which is totally enough for painting 2D maps and standard routing queries. As the elevation is not added to OpenStreetMap data directly (and it is also not intended to be added to the OSM data base), a component was needed that parses both Nasa SRTM data as well as OSM data files in order to combine the data.

In the first version, we parsed the SRTM data directly and addied it to the nodes of the OSM-Graph directly. During one refactoring, we decided to integtrate Osmosis into the project in order to be able to read PBF files (another OpenStreetMap file format). During this integration we decided to separate the SRTM parsing into a separate module so that other people can make use of it as well. The plugin was open sourced some time ago at google code as the “osmosis-srtm-plugin” under an LGPL licence.

Relevant Links:

• Project page at GoogleCode
• plugin page at OpenStreetMap
• The TrafficMining project
• OpenStreetMap
• Osmosis
• NASA SRTM

Drupal shows warnings after migrating to new server

Recently we migrated a Drupal managed website to  a new server. – Everything was fine, just on some pages, some php-warnings showed up that did not show up on the original site.
After some investigation I checked php’s error_reporting setting and realized that the settings of the new new server were more sensitive than the old one.

The solution was pretty simple. As I definately didn’t want to start hacking around in Drupal, I just turned off showing the errors to the user:

Administer > Site configuration > Error reporting
(or in german:) Verwalten > Einstellungen > Error reporting
/admin/settings/error-reporting
Error Reporting: Write errors to the log (instead: Write errors to the log and to the screen).

Pretty easy.

Sometimes AntiVirus Scanners just suck

Due to some very strange and non reproducible bugs I deleted my NetBeans profile to get back to a fresh post-install state. This mainly hat two very different results: A positive one and the one why I am writing this post. The positive one is/was that the mystery-bug disappeared.

After deleting the profile, NetBeans wants to update all its modules to the latest releases – which is okay.
The problem however was that NB never managed to download all the modules and just got stuck randomly between 0% and 100%. NB just said “downloading …” but the task manager showed 0 bytes/sec traffic. First I thought that the download/update servers might be overloaded. After 3 days of repeatedly trying -  I was very douptful about that first guess. Finally I sent an email to the NetBeans mailinglist, if s.o else also experienced such a problem.

The first answer came in just 70min after my question saying “I had this problem and found that if I turn off AVG I could get the plugins.”.
Uhoh – I didn’t mention my AV scanner in my post – yet I am using AVG, too. And – surprise – after disabling resident shield, mail-scanner, link-scanner and identity protection – NB suddenly was able to update to the latest version. Unfortunately AVG never said that it was doing something of that kind!

So the lesson learned: If some really weird stuff is happening, try to disable the AV scanner – but don’t forget to re-enable it!

Update: same happens with Eclipse when downloading/installing plug-ins. – At least AVG is consistent with blocking Java-IDEs.

Finished my Posters for ICIP and MICCAI

Finally finished the posters for my publications:

F. Graf, H.-P. Kriegel, M. Schubert, S. Poelsterl, A. Cavallaro
2D Image Registration in CT Images using Radial Image Descriptors
In Medical Image Computing and Computer-Assisted Intervention (MICCAI), Toronto, Canada, 2011.

and

F. Graf, H.-P. Kriegel, M. Weiler
Robust Segmentation of Relevant Regions in Low Depth of Field Images
In Proceedings of the IEEE International Conference on Image Processing (ICIP), Brussels, Belgium, 2011.