cv.jit.trackpoints This external only accepts the 3-plane float matrices output from cv.jit.track. When using large number of points with cv.jit.track, displaying the position of these points can be problematic. This external only accepts the 3-plane float matrices output from cv.jit.track. You must manually specify the size of the output matrix with the "size" attribute, followed by the width and height. Normally, this will be the same as the size of the matrices being sent to cv.jit.track. The cells of the output matrix corresponding to the position of the points in the input matrix will be set with each pointÕs index values. In order to avoid labeling points starting at 0, all indices are offset by one. I.e. 1 to 255, rather than 0 to 254.

from the library : cv.jit Format : External Environment : jitter / max / msp freeware Max 4.x http://www.iamas.ac.jp/~jovan02/cv/download.html