Sure, I have a series of lighting vector directions (LD) and measured pixels intensities (I) and I would like to find the unknown lighting strength (lambda) parameters from the measured pixels intensities. The cost function can be in from of
where M is the number of images and N number of pixels. By assuming the directional lighting model, the strength (lambda) can be estimated
where
the author suggested that the minimization over "bj " inside the sum can be analytically solved, resulting in a cost function below
Thank you for your help.