Web Cam Progress

Have made some progress on the web cams. When I left today there was one webcam setup in the level four lab facing the street. We have bumped up the screen capture rate from 60 seconds to 1 second in order to capture the dynamics of the street (cars passing, people hanging around etc.).

The webcam feed is stored onto the local computer. A chat to IT and a bit of setup work now allows us to directly access that computer. We had trouble with storing the images on the global public drive as the network traffic was lagging the screen captures.

Can get the video playing in Processing now. Also we have started to manipulate the stream. Introducing a threshold filter converts the image to a black and white rendering based on light levels / movement. We then adapted the blob detector from the processing website to start detecting people / cars. A bit of tweaking to the colours / settings and working with fades has proven to produce really interesting results. Will have to post some images tomrrow.

Using this setup, we are planning to setup some more cameras.

One error we get is if the webcam has missed a frame (due to lag or the camera stopping etc.), I am having issues recognising that this file is not existent. My current strategy is to load the image using loadImage() command. If the file isn’t there it returns null. So I am checking that before I produce the image and it seems to be working, but then it stalls.

Any idea (or example code) for checking if the file exists or not? Will post images / code tomorrow.




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