Image Requirements for Three-Dimensional Measurements of Pavement Macrotexture

This paper examines the effect of wavelength range on the estimation of pavement macrotexture quality from a three-dimensional (3-D) surface model. Macrotexture indicators computed from two-dimensional (2-D) profiles are compared with power spectrum energy computed from 3-D surface heights in the frequency domain. Pavement samples with different types of surface conditions were evaluated by means of a noncontact photometric stereo system. For each pavement sample, surface heights were recovered and a 3-D surface model was constructed. Surface profiles were also measured manually with a dial gauge. The surface heights in frequency domain were divided into 10 wavelength ranges. Power spectrum energy was computed for each wavelength range. The correlation between the 2-D indicators (mean profile depth and root mean square roughness) and the power spectrum energy was examined. It was found that the texture indicators computed from the 3-D recovered surface could represent the 2-D indicators adequately. Moreover, the power spectrum energy provided a good estimation of the 2-D indicators when it was computed from wavelength ranges of approximately 13 times the expected range of the 2-D indicators.