In this paper we present a new method for solving the uncalibrated photometric stereo problem in the Lambertian framework, based on the hypothesis that all lightings share the same intensity, which we can estimate. We show how this estimation allows one to solve the ambiguities of the linear Lambertian model, especially the so-called generalized bas-relief ambiguity. As the problem becomes well...

Results of the first comprehensive light pollution survey in Hong Kong are presented. The night-sky brightness was measured and monitored around the city using a portable light-sensing device called the Sky Quality Meter over a 15-month period beginning in March 2008. A total of 1,957 data sets were taken at 199 distinct locations, including urban and rural sites covering all 18 Administrative ...