An orthogonal feature preserving filter

Ultrasound B-scan images suffer from characteristic noise referred to as speckle. The feature-preserving nature of the median filter and variations based on it make this class of filters ideal candidates for processing ultrasound images. Two-dimensional median filters are not as well behaved in practice as their one-dimensional counterparts, and tend to distort desirable signal features during filtering process. Alternate techniques are proposed to alleviate this problem, with nonlinear filters gaining predominance. These techniques are typically iterative and unsuited for high speed applications. The filter proposed is motivated by the need for ensuring high performance, while minimizing processing time