基于四元数理论的彩色图像脉冲噪声开关滤波

Quaternion based switching filter for impulse noise removal in color images

根据四元数单位变换理论定义了一种新的描述彩色图像像素点间差异的距离,该距离可以同时描述两个彩色像素点在强度和色度上的差异.利用该距离和图像边缘的结构性与方向性,构造了一种基于四元数的开关型彩色图像脉冲噪声滤波器.该滤波器对像素点进行4个方向上的噪声检测并仅对检测为噪声的像素点进行滤波.实验表明:该滤波器能够在去除彩色图像中的相关和非相关噪声的同时保护图像细节,同时具有比传统方法更快的执行速度.

A novel color pixel distance based on the quaternion unit transform was proposed to quantify the intensity and chromaticity differences between two color pixels simultaneously.A quaternion switching filter was presented to suppress the impulse noise in color images based on the aforementioned distance and the property of image edge in both structure and direction.Each pixel in the color image was detected along four directions to determine whether it was noisy and only the noisy one was removed by the filter.The experimental result indicates that the proposed filter can suppress both correlated and uncorrelated impulse noise in color image while preserve image detail and has a faster execution speed than the traditional filters.