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  1. PO
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    <p>Putting in the relevant code would help. Also knowing what you're actually trying to achieve.</p> <p>Which two images are you subtracting? I've done subtracting subsequent images (so, images taken with a delay of a fraction of a second), and the background subtraction generally results in the edges of moving objects, for example the edges of a hand, and not the entire silhouette of a hand. I'm guessing you're taking the difference of the current frame and a static startup frame. It's possible that parts aren't different enough (skin+skin).</p> <p>I've got some computer problems tonight, I'll test it out tomorrow (pls put up at least the steps you actually carry thorough though) and let you know.</p> <hr> <p>I'm still not sure what your ultimate goal is, although I'm guessing you want to do some gesture-recognition (since you have a vector called "fingers"). As Manpreet said, your biggest problem is robustness, and that is from the subjects having similar color.</p> <p>I reproduced your image by having my face in the static comparison image, then moving it. If I started with only background, it was already much more robust and in anycase didn't display any "overlaying".</p> <p>Quick fix is, make sure to have a clean subject-free static image. Otherwise, you'll want to have dynamic comparison image, simplest would be comparing frame_n with frame_n-1. This will generally give you just the moving edges though, so if you want the entire silhouette you can either:</p> <p>1) Use a different segmenting algorithm (what I recommend. Background subtraction is fast and you can use it to determine a much smaller ROI in which to search, and then use a different algorithm for more robust segmentation.)</p> <p>2) Try to make a compromise between the static and dynamic comparison image, for example as an average of the past 10 frames or something like that. I don't know how well this works, but would be quite simple to implement, worth a try :).</p> <p>Also, try with CV_THRESH_OTSU instead of 30 for your threshold value, see if you like that better.</p> <p>Also, I noticed often the output flares (regions which haven't changed switch from black to white). Checking with the live stream, I'm quite certain it because of the webcam autofocusing/adjusting white balance etc.. If you're getting that too, turning off the autofocus etc. should help (which btw isn't done through openCV but depends on the camera. Possibly check this: <a href="https://stackoverflow.com/questions/1717780/how-to-programatically-disable-the-auto-focus-of-a-webcam">How to programatically disable the auto-focus of a webcam?</a>)</p>
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    1. POOpenCv Issue of Image Subtraction?
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    1. USCommunity
    1. USSteve Heim
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    1. COyou are right.. i do take a static image and then try to subtract it from webcam query image.... this is my code...
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      1. USAshwin Gopalakrishnan
    2. COyou are right.. i do take a static image and then try to subtract it from webcam query image... this is the link to my code....please help. http://www.2shared.com/document/0LaAP-mQ/subtraction.html
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      1. USAshwin Gopalakrishnan
    3. COI added an answer more specific to your code. Hope this helps, depends a bit on what you really want to achieve though. On a side note, unless you have specific reasons not to, I would recommend adopting the newer C++ standards of openCV, namely using Mat for your images.
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