闪光CCD图像的中值-非线性扩散滤波

根据闪光CCD图像的特点,提出了一种中值-非线性扩散滤波(Median-NonlinearDiffusionFiltering,简称MNDF)方法。该方法采用中值预滤波来估计图像的真实边缘,通过求解偏微分方程(PartialDifferentialEquation,简称PDE)来进行非线性扩散滤波,充分发挥了中值滤波和非线性扩散滤波的优势,能更好地消除噪声、保护边缘。实验结果表明,在高斯噪声和脉冲噪声同时存在的情况下,MNDF方法取得的滤波效果较P-M方案和Catte方案要好,信噪比改善因子提高3~5倍,均方误差减小1.3~2.7倍。对闪光照相CCD图像取得了很好的消噪声结果,保护了边缘信息。

Nonlinear diffusion filtering method for flash X-ray CCD images

According to the characteristics of flash X-ray radiographic CCD images, a new diffusion filter called median-nonlinear diffusion filter (MNDF) was proposed in the paper. This method estimates image edges based on median filtering image. Then, by solving a PDE (partial differential equation), a filtered image can be derived. From which, the nonlinear advantage of the median filters and the nonlinear diffusion filters can be utilized to eliminate noise and preserve edges more efficiently. Experiments show that the method can eliminate the combined noises of Gaussian noise and the impulse noise efficiently while preserving edge details. The PSNR (Promotion of Signal-to-Noise Ratio) of the new method is 3~5 times higher than that of traditional methods and its MSE (mean square error) is 1.3~2.7 times smaller than that of traditional method. Good denoising results for flash X-ray radiographic CCD images are obtained with image edges preserved.