P1A-13 Speckle Suppression Using Maximal-Brightness-Difference-Based Adaptive Median Weighting

In this paper, we proposed a new adaptive median filter for ultrasonic image despeckling. Speckle is removed by the filter based on directional brightness differences when the mask is divided at different angles. The median value in each direction is weighted by the brightness difference of that angle. For a homogeneous region, the brightness difference is similar in all directions and the median values are equally weighted for maximal smoothing. On the other hand, a larger brightness difference is detected in one specific angle when the mask covers a resolvable contour. The filter preserves the contour by giving the median value along that direction a larger weighting. The weighting can be further adjusted by using brightness difference with different powers. The new filter was examined using simulated and in-vivo ultrasound images. Results show that it is superior to the AWMF filter in computational efficiency and detail preserving with similar speckle suppression.