Histogram-Based Fast Adaptive Bilateral Filter for Ultrasound Speckle Reduction

Tissue structure including lesions in ultrasound images is important in clinical diagnosis. The way to suppress noise effectively and to preserve the structure is vital for diagnosis and also for image postprocessing. In order to reduce speckle and improve the quality of ultrasound images, this paper presents a fast adaptive bilateral filter (FABF) based on local histogram. The presented filter is derived from a conventional bilateral filter and is adaptively adjusted by speckle detection based on histogram matching. The criterion of speckle region is defined from a similarity value obtained from local histogram matching between the processing window and a reference speckle area. The presented filter can effectively reduce the speckle noise and, at the same time, maintain the tissue structure. In phantom and in vivo data, the proposed method can improve the quality of an ultrasound image in terms of tissue SNR and CNR values.