We present an algorithm for separating the local gradient information and Lambertian colour by using 4-source colour photometric stereo in the presence of highlights and shadows. We assume that the surface reflectance can be approximated by the sum of a Lambertian and a specular component. The conventional photometric method is generalised for colour images. Shadows and highlights in the input images are detected using either spectral or directional cues and excluded from the recovery process, thus giving more reliable estimates of local surface parameters.
Highlight and shadow detection is done in the same way as Barsky and Petrou REF .
The 4-source photometric stereo technique for three-dimensional surfaces in the presence of highlights and shadows
IEEE Trans. Pattern Anal. Mach. Intell.
IEEE Trans. Pattern Anal. Mach. Intell.
Computer Science