Ultrasound Image Enhancement using Dynamic Filtering

This paper presents an adaptive image enhancement method through selected dynamic filtering based on speckle detection for ultrasound images. The main idea is to enhance the tissue structure and also smooth the speckle regions adoptively from pre-defined filters with certain filter characteristics. The criterion of speckle region is defined from a similarity value obtained from histogram matching between the histogram in the processing window and a reference one derived from a speckle area. Big similarity values means speckle pixels needed smoothing from lowpass filtering, and small values correspond to structure pixels which will be enhanced by highpass filters. All these filters can be implemented as dynamic filtering whose index is the similarity value for adoptively smoothing speckle for contrast enhancement or enhancing structure for better edge/boundary detection. Test images show that our new method can enhance tissue structure and also reduce speckle for better image quality.