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    <p>Getting motion detection to work using the libraries you mention is trivial. Following is an AForge (version 2.2.4) example. It works on a video file but you can easily adapt it to the webcam event.</p> <p>Johannes' is right but I think playing around with these libraries eases the way to understanding basic image processing.</p> <p>My application processes 720p video at 120FPS on a very fast machine with SSDs and around 50FPS on my development laptop.</p> <pre><code>public static void Main() { float motionLevel = 0F; System.Drawing.Bitmap bitmap = null; AForge.Video.FFMPEG.VideoFileReader reader = null; AForge.Vision.Motion.MotionDetector motionDetector = null; motionDetector = GetDefaultMotionDetector(); reader.Open(@"C:\Temp.wmv"); while (true) { bitmap = reader.ReadVideoFrame(); if (bitmap == null) break; // motionLevel will indicate the amount of motion as a percentage. motionLevel = motionDetector.ProcessFrame(bitmap); // You can also access the detected motion blobs as follows: // ((AForge.Vision.Motion.BlobCountingObjectsProcessing) motionDetector.Processor).ObjectRectangles [i]... } reader.Close(); } // Play around with this function to tweak results. public static AForge.Vision.Motion.MotionDetector GetDefaultMotionDetector () { AForge.Vision.Motion.IMotionDetector detector = null; AForge.Vision.Motion.IMotionProcessing processor = null; AForge.Vision.Motion.MotionDetector motionDetector = null; //detector = new AForge.Vision.Motion.TwoFramesDifferenceDetector() //{ // DifferenceThreshold = 15, // SuppressNoise = true //}; //detector = new AForge.Vision.Motion.CustomFrameDifferenceDetector() //{ // DifferenceThreshold = 15, // KeepObjectsEdges = true, // SuppressNoise = true //}; detector = new AForge.Vision.Motion.SimpleBackgroundModelingDetector() { DifferenceThreshold = 10, FramesPerBackgroundUpdate = 10, KeepObjectsEdges = true, MillisecondsPerBackgroundUpdate = 0, SuppressNoise = true }; //processor = new AForge.Vision.Motion.GridMotionAreaProcessing() //{ // HighlightColor = System.Drawing.Color.Red, // HighlightMotionGrid = true, // GridWidth = 100, // GridHeight = 100, // MotionAmountToHighlight = 100F //}; processor = new AForge.Vision.Motion.BlobCountingObjectsProcessing() { HighlightColor = System.Drawing.Color.Red, HighlightMotionRegions = true, MinObjectsHeight = 10, MinObjectsWidth = 10 }; motionDetector = new AForge.Vision.Motion.MotionDetector(detector, processor); return (motionDetector); } </code></pre>
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    1. COThis actually got me some really good results! :) I found that moving the camera would mess things up though. But when it's standing still it is now detecting movement perfectly ^^ However, I was still wondering on how you apply the detected areas to the bitmap image before it is shown on the form.
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    2. COThe line `HighlightMotionRegions = true` takes care of that. You can turn it off and render custom overlays yourself if you like. These basic algorithms are meant to work with stationary cameras. Moving cameras use far more complex algorithms. Please keep in mind that the code above simply highlights motion. It does NOT track objects. You will need to write code yourself to associate blob identity frame-to-frame.
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    3. COah, that's wondeful. I had it spying in the street yesterday, and it worked ok. But i found that it was a little oversenitive, espiecally when the wind was blowing :I
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