Breast tumor segmentation with prior knowledge learning

Hybrid methods filtering of images generally put in collaboration two filters: the first is used for the pre-smoothing and the second to finalise the filtering operation. This approach permits to smoothen the image efficiently while preserving at best its contours and fine structures. Unfortunately, the pre-smoothing generally induces a blur which is not taken into account during the smoothing. In this study, the authors propose a hybrid diffusion method based on the Jeffreys-type equation (JTE). The method proposed provides two steps: a pre-smoothing stage called adaptive-linear diffusion (A-LD) and a smoothing stage called Jeffreys anisotropic diffusion (JAD). A stopping criterion for A-LD, called variance absolute error (VAE) which estimates the noise level, is proposed in order to guarantee the optimality of the smoothing filter. A diffusion function is proposed as well in order to take into account the blurring induced by the pre-smoothing. The proposed hybrid method is compared with the Perona and Malick, telegraph equation, artefact suppressed large-scale non-local means and Xu-AD models. Experimental results show that the proposed hybrid method is efficient both on noise reduction and preservation of contours and fine structures.

Hybrid model of diffusion based on the Jeffreys-type equation for noise reduction on images

Speckle noise contaminates medical ultrasound images and the suppression of speckle noise is valuable for image interpretation. This paper presents a new method for speckle suppression by integrating the non-local means (NLM) with the McIlhagga-based anisotropic diffusion (MAD). The MAD is first used to get a diffused image from the initial noisy image, and then the NLM is conducted to get a final denoised image by processing both the initial image and the diffused image. Experimental results on both simulated and real ultrasound images validate the feasibility of the method and demonstrate its superiority to seven state-of-the-art methods in terms of noise reduction and detail preservation.

Haiwu Zhao

Papers

Speckle suppression of ultrasonic images using non-local means and McIlhagga-based anisotropic diffusion