A speckle suppression method based on nonlinear threshold wavelet packet in ultrasound images

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, a n original image was separated into two parts by adaptive prefiltering. The se two parts were then transformed into a multiscale wavelet packet (WP) do main and the WP coefficients were processed by a soft thresholding filter m ethod. 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 now 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 fo und that this technique reduces the speckle noise effectively, and preserve s the resolvable details.