About a year ago I posted here about a Qt+OpenCV project in Code::blocks I was working on. Since then I switched to Qt Creator, simplifying the whole thing, and then moved the code on Google Code. It is a very, very simple computer vision algorithm development sofware and should be seen as an helper for beginners who wish to use Qt and OpenCV. It comes as a movement detector with a sleep/auto-rearm function (that's where the PoolWatcher Qt .pro project name comes from, put it on ("surveiller") and an alarm will ring in case of intrusion, the goal there being to prevent young kids drowning), but can be easily modified to suit your needs (since it is based on a strategy pattern all you will have to take care of is your vision class which will be a sub-class of AlgoVision, and you can easily modify the UI as well, using Qt Designer). The PoolWatcher vision algorithm (detecKidAlgo) is at its early stage and needs big improvments, so far it uses only image subtraction with mixture of gaussian and then cvBlob for the tracking part. Being involved in several other projects I don't have much time to work on that, so let me know if you are interested and wish to contribute to it or to other parts of the project. You will find the code here.
If you are not interested in the development and want to use the PoolWatcher as a videosurveillance software without having to compile it, an executable file with its dependencies is available here. It has been tested under Windows 7 64 bits, it is probably buggy though, so let me know if you have any problem or suggestion and I'll do my best to improve it.
Below are two videos showing the program running with and without debug mode.