Movement detection, in graphs

Earlier, we decided to take into account the ratio of height and width when detecting the blob types. If the height's greater than the width, then it's most likely a person. Likewise, if the width's greater than the height, then the movement is most likely from a car. We've also decided to "merge" blobs--that is, take smaller blobs near each other and combine them.

Here is a graph of the movement detected from one of the AP&M videos:



(person, walking from the right hand side of the video to the left)



(car driving from the right to the left)

In both cases, the system detected the correct type of movement. However, the system tends to get confused often. It seems like the amount of white in the differencing might be too low to detect more than small blobs. We're correcting for this for the time being by assuming that each blob is 20x20 for the purpose of tracking (the original sizes are still used for type detection). We'll continue gathering data to determine the accuracy of our algorithm.