Real-time speckle reduction and coherence enhancement of ultrasound images based on anisotropic Savitzky-Golay filters

This paper describes a new filtering algorithm developed for real-time speckle reduction and coherence enhancement of ultrasound images. The new filter, referred to as the anisotropic Savitzky-Golay filter, is the two-dimensional, weighted Savitzky-Golay filter enhanced with a mechanism for adjusting both the degree and direction of the smoothing so that they both match the anisotropic properties of each local regions in the image. The results comparing the new filter with adaptive speckle reduction and adaptive weighted median filters on a synthetic test pattern and an ultrasound thyroid image are also reported.