A noise removal algorithm for DR Images based on adaptive estimation of threshold
Xiong Xiong, Bangshu, Jia Jia, Бей, Yu Yu, Lei Lei, Zha, Ping-jun · Acta Scientiarum Naturalium Universitatis Sunyatseni · 2012
When DR (Digital Radiography) images are filtered, it is necessary to preserve the edges and key details. But the existing methods may inevitably take fine details mistaken for noise to remove. In order to solve the problem an improved anisotropic diffusion filtering model is proposed. Firstly, a novel diffusion function is introduced based on Perona and Malik model, which well overcomes the high rate of convergence. Secondly, the gradient threshold is modified to an adaptive estimation function, so it is better at adaptive threshold regulations according to the pixels and iteration times. Finally, the edges are extracted from the restored images and the results are evaluated quantificationally. It is shown from the experiments that the proposed method is effective not only in noise reduction but also in details preserved.