| 摘要 |
A pixelated image affected by a light source 250 and silhouette boundary of an object in the image are received, the image is filtered to decrease diffuse reflectivity and a local maxima pixel around the silhouette boundary 252 is identified in order to estimate the presence of a light source, then the slant angle (zenith) 256 is estimated using the silhouette boundary and tilt angle (azimuth) 258 is estimated by analyzing a pixel along a slant angle direction vector 254 associated with the slant angle, the slant and tilt angles then being output. The pixel having the lowest intensity may be identified, and this intensity used as the ambient light intensity. The intensity of the light source may be estimated. Plural light sources may be identified and their relative intensities estimated. Estimating the tilt angle 258 may comprise determining an intensity gradient along the slant angle direction vector 254, wherein if the gradient increases, a pixel having the highest intensity is used, and if the gradient decreases, a pixel having the lowest intensity is used and 90 degrees is added to the pixel tilt angle. |
