v.colourfilter Each output pixel represents the degree to which that pixel fits the colour description. Each output pixel represents the degree to which that pixel fits the colour description. If the incoming stream is rgb format, then rgb colour matching is used. If the incoming stream is in yuv format, then yuv colour matching is used. yuv offers better tracking of colours in highlight and shadow since it separates colour from brightness. To track an object with many levels of brightness, use a very high y (brightness) tolerance (256) and low (1-4) u and v tolerances). Normal tolerances for yuv: y tolerance = 4 - 256 u and v tolerances = 1 - 8 Normal tolerances for rgb: r, g, and b tolerances = 4 - 16 For grays images, v.colourfilter outputs how close the input pixels are to the y center.

from the library : softVNS Format : External Environment : jitter / max commercial Max 4.x http://homepage.mac.com/davidrokeby/softVNS.html