CAJ | 학술논문

路面图像的复杂性及裂缝信息的弱信号性导致对路面裂缝进行检测非常困难,为此提出一种基于非下采样contourlet变换(NSCT)和图像形态学的路面裂缝检测算法.首先对图像进行NSCT得到不同尺度、不同方向上的变换系数,在NSCT域中根据变换系数自适应地确定阈值,并应用广义非线性增益函数来增强较弱细节的局部对比度;然后对增强处理后的变换系数进行反变换;最后用图像形态学方法和中值滤波实现裂缝检测及孤立噪声点去除.通过对实际的高速路面图像测试表明,与直方图增强、小波变换及contourlet变换相比,该算法能更有效地增强弱对比度的细小裂缝,克服了常规算法易受离散噪声点以及光照条件等干扰的问题,具有较强的鲁棒性且高效实用.
로면도상적복잡성급렬봉신식적약신호성도치대로면렬봉진행검측비상곤난,위차제출일충기우비하채양contourlet변환(NSCT)화도상형태학적로면렬봉검측산법.수선대도상진행NSCT득도불동척도、불동방향상적변환계수,재NSCT역중근거변환계수자괄응지학정역치,병응용엄의비선성증익함수래증강교약세절적국부대비도;연후대증강처리후적변환계수진행반변환;최후용도상형태학방법화중치려파실현렬봉검측급고립조성점거제.통과대실제적고속로면도상측시표명,여직방도증강、소파변환급contourlet변환상비,해산법능경유효지증강약대비도적세소렬봉,극복료상규산법역수리산조성점이급광조조건등간우적문제,구유교강적로봉성차고효실용.
The complex nature of road images and weak signal make the detection pavement cracks particularly difficult. An algorithm for pavement cracks detection based on nonsubsampled contourlet transform (NSCT) and morphology is proposed. Firstly, the coefficients at different scales and in different directions are obtained by image decomposition using the NSCT, then coefficients thresholds are adaptively set and the generalized nonlinear gain function is used to enhance the features with low contrast while preventing the strong contrast features from over enhancing in the NSCT domain. After the enhancement, the inverse transform is performed, and morphological and median filters are employed to detect cracks and remove noise. The proposed algorithm is tested by real highway pavement images. The experimental results show that our algorithm is more robust and effective to detect road cracks especially for weak contrast cracks and thin cracks than other algorithms, such as histogram enhancement, wavelet transform, or contourlet transform.