CamSurveillance Manual
Part 1: General Remarks

CamSurveillance needs for the working with the network cameras their IP addresses. From these IP address the program receives the current camera picture. The picture receiving is done by a separate started thread. If a picture was correct received and the motion detection is activated, then a further thread is started for comparing the pictures and determine the difference. If the receiving intervall is shorter than the motion detecting intervall, the receiving intervall is reduced to the motion detecting intervall while motion detection is running. This is necessary, because the program needs a new picture before it can start the difference checking. So if the receiving and testing intervalls are very short, there are always 2 threads per camera running. Remember this if your PC is using a lot of % CPU for the CamSurveillance.

If you are receiving more pictures as your camera is able to generate ( the receiving intervall is 1 sec, but your camera captures pictures only every 3 sec ) you receive often the same picture twice. So it makes no sense to receive more pictures as there are new ones available.

The needed picture format is JPG. So please adjust the camera that it generates only JPG pictures. The resolution is not important, but remember if the program receives a picture which has 640x480 pixels, it must transfer much more pixels as if the picture would have only 320x240 pixels. And the program has to test 4 times the amount of pixels while the intern difference test.

The program can display the video in the video window in different formats. 24 bit color ( only if a colored picture was received ), 8 bit greyscale, 4 bit greyscale, 1 bit greyscale. The intern picture format is always after receiving 24 bit. So it costs no performance to display the video in 24 bit. The reduction into 8,4,1 bit greyscale costs a little bit CPU and is only important for viewing the video in the testing format. While motion detection is running the program can change the received picture format from 24 bit ( which is the default format after receiving ) into 8,4,1 bit greyscale before the intern testing routine starts. The reduction into greyscale costs a little bit CPU, but the testing routine works 3 times faster as if you use 24 bit for the intern format. If you have an up to date CPU it makes no noticeable difference which format you use. The main reason for using a greyscale format for the intern testing routine is, to reduce the influence of brightness in the video picture on the result of the picture difference testing. Try the different intern picture formats and see how the picture differences changes.

All digital cameras generates different pictures from the same situation also if there are no changes. If you algin your camera to view on a wall where nothing is moving and let the motion detection run, you get little picture differences, because the generated pictures are different. This happens on the way from the analog world into the digital picture from your camera. To see these differences ( not only these, but all differences ) you can select in the program to show you the different pixels in the video window. This is a good way to see how good or bad your camera works. To reduce this differences which are in reality not existing, you have to adjust the pixel difference value. Try the different intern picture formats with different pixel difference values to find the best solution for your camera and situation.

Part 2 >>