频域滤波的水泥路面图像降噪增强方法

针对在水泥路面裂缝图像识别中刻槽和纵向条带状形成的噪声干扰，提出了一种基于频域滤波的降噪增强方法。首先，分析了这两类噪声的频谱特征，并根据空域图像中刻槽的周期性，推导了频域图像中刻槽谱峰的位置，设计了消除这些谱峰的系列滤波器。根据纵向条带状干扰属于低频成分的特性，设计了抑制低频、增强高频的滤波器，经优化滤波器参数达到消除这类干扰的效果。实验结果表明，该方法能够消除两类噪声干扰，同时，增强了裂缝的对比度，为水泥路面裂缝识别提供了理论基础。

Denoising and enhencing method in cement pavement image based on frequence domain filter

A denoising and enhancing method based on frequence domain filter was developed aiming at two main noise in cement pavement image: groove noise and longitudial stripe noise. Firstly, the spectral features of the two kinds of noise were analyzed. On this basis, the position of groove spectral peaks in the frequency domain were deduced according to the groove period in spatial domain. Then, a series offilters were designed to elimiante these peaks in the frequency domain. Moreover, aiming at the longitudianl stripe noise belonging to the low frequency components, a filter of which parameters were optimized through experiments, was designed to eliminating this disturbance by suppressing low frequency and enhancing high frequency. Finally, the experimental results showed that this proposed method can eliminate the two kinds of noise and enhance the constrast of cracks, which provided a foundation for crack recognition in cement pavement.