光学学报, 2006, 26 (3): 341, 网络出版: 2006-04-20
基于高速公路裂纹局部线性特征内容的脊波变换域算法研究
Algorithm Research in Ridgelet Transform Domain Based on the Image Content of Freeway Local Linear Crack
图像处理 脊波变换 拉东变换 线性裂纹 小波变换 image processing ridgelet transform Radon transform linear crack wavelet transform
摘要
利用频域中傅里叶变换投影定理,提出一种新的离散脊波实现算法,应用于高速公路局部线性裂纹的检测取得较好效果。详细阐述了离散脊波的实现步骤以及对标准图像进行脊波变换的模拟结果,并提出拉东(Radon)变换重建原图像的基本条件。上述定理应用于复杂背景下的路面检测,结合直方图均衡化算法消除背景噪声;选用基于样本估计的阈值方法对脊波分解的各层系数进行处理去除随机噪声。选用不同的重构系数进行计算,得到脊波变换后重构图像的信噪比优于二维小波变换(低频大于20 dB)以及二维小波变换加魏纳滤波变换(平均大于3 dB)。通过图像的二值化处理提取局部线性裂纹,其分辨力极限达到2 mm精度。
Abstract
A new algorithm is proposed, through Fourier transformation projection theory using frequency-domain analysis, to detect local linear cracks on the freeway surface. And valid results are obtained. The steps of discrete ridgelet algorithm and the ridgelet transform results of the standard image are represented in detail. The basic condition of reconstructing the original image through Radon transformation is proposed. The method is used to detect actual complex surface, and denoise background noise combined with the histogram equilibrium algorithm. Estimated sample threshold is used to treat the level coefficients of ridgelet transform and get rid of the Random noise. The signal-to-noise ratio of ridgelet transform is better than that of the two-dimensional wavelet transform (greater than 20 dB in the state of low-frequency) and wavelet transform plus Weiner filtering (greater than 3 dB on the average) through counting the different reconstruction coefficients. The local linear crack is picked up through binary image and the resolution factor is within 2 mm.
王刚, 贺安之, 肖亮. 基于高速公路裂纹局部线性特征内容的脊波变换域算法研究[J]. 光学学报, 2006, 26(3): 341. 王刚, 贺安之, 肖亮. Algorithm Research in Ridgelet Transform Domain Based on the Image Content of Freeway Local Linear Crack[J]. Acta Optica Sinica, 2006, 26(3): 341.