Abstract

Background: Medical ultrasonic images are usually degraded by a special kind of noise called ’speckle'. The speckle noises usually have an effect more on edges and fine details of an ultrasound images which lead to reduction in their contrast resolution consequently create difficulties in the diagnosis of illnesses.

Methods: In this paper, to reduce the speckle noise of medical ultrasound image, we have proposes a denoising approach by using ’discrete shearlet transform' based on pseudo-polar fast Fourier transform. The mathematical structure of present method is briefly discussed. To illustrate the efficiency of proposed approach, the experimental results of synthesis of some real Ultrasound images are considered.

Results: Experimental results illustrate that proposed approach can obtain better performance in terms of Peak Signal To Noise Ratio (PSNR) for ultrasound image denoising. Our numerical tests include a series of computer-simulated and in MATLAB experiments.

Keywords: Discrete shearlet transform, fourier transform, image denoising, PSNR, threshold, ultrasound Image.

Graphical Abstract