A recursive estimation of parameters of straight lines and circles: application to the segmentation of the Rey´s Complex Figure

We explain a new approach in on-line segmentation of handwritten drawings by estimating circle bows or linear segments. In these two cases, we use an extended Kalman filter. The state and observation equations come from cartesian equations of these geometrical shapes with no-varying parameters to estimate. The parameters are recursively estimated with a very good accuracy during the acquisition of the points. The method is tested on a particular kind of handwritten drawings: the Rey´s Complex Figure (Rey, 1942), used in neurological and psychological diagnosis in children. From the proposed segmentation, it should be easier to obtain the features retained by the psychologist in his analysis