A SPECKLE SUPPRESSION METHOD BASED ON NONLINEAR THRESHOLD WAVELET PACKET IN ULTRASOUND IMAGES
一种基于非线性域值小波包的超声图像闪斑抑制方法

A novel method based on nonlinear threshold wavelet packet was explored in order to suppress the speckles in B scan 3 D ultrasound imaging. Firstly, an original image was separated into two parts by adaptive pre filtering. These two parts were then transformed into a multiscale wavelet packet (WP) domain and the WP coefficients were processed by a soft thresholding filter method. The processed coefficients for each part were then transformed back into the space domain. Finally, the de noised image was obtained as the sum of the two processed parts. Performance of this new method has been tested by a computer simulated image. Ultrasound images set of a plastic bowl in a water tank has been utilized for 3 D ultrasound reconstruction. It was found that this technique reduces the speckle noise effectively, and preserves the resolvable details.