Patent ID: 8063949

Claim:
An activity-based system for reducing Gr-Gb gain imbalance, comprising: a sensor configured to provide an input Bayer pattern array containing amplitudes corresponding to Gr and Gb cells; and a processor coupled to said sensor and configured to compute for at least some of said Gr and Gb cells: activity measures for pluralities of adjacent, same-type cells, green precompensation factors based on said activity measures, averages for said pluralities of adjacent, same-type cells, and averages for pluralities of adjacent, opposite-type cells and use said green precompensation factors, said averages for said pluralities of adjacent, same-type cells and said averages for said pluralities of adjacent, opposite-type cells to form an output Bayer pattern in which said Gr-Gb gain imbalance is reduced, wherein said green precompensation factors are further based on a piecewise linear transfer function which is ming for G act < Thr ming + S * (Gract − Thr) for Thr ≦ G act < Thr + (maxg − ming)/S maxg for Thr + (maxg − ming)/S ≦ G act , wherein Gract is the local G r activity and G act =|Σ 0≦i≦8 w i G i | and wherein ming is a minimum green amplitude, maxg is a maximum green amplitude, Thr is a threshold and S is a slope.