| Wavelet analysis is a processing technique that can be used to characterize variations within a signal or image. In this work, we employ wavelet analysis on LiDAR reflectivity data of a rock face to delineate the boundaries between different material types. We extract a two-dimensional intensity image map and perform the two-dimensional continuous wavelet transform to obtain wavelet coefficients at each pixel in the image for a single wavelet scale. Within a zone that contains a single material type, the wavelet coefficients are relatively uniform; while between zones, the wavelet coefficients change abruptly. We delineate the boundaries between zones as the locations where the spatial rate of change of the wavelet coefficients attains its local maximum. We investigate the range of wavelet scale parameters that lead to optimal boundary delineation. The boundary locations delineated through the wavelet analysis technique correlate well with the observable sediment structure. |
