How to choose the trade-off parameter λ

The λ controls the trade-off between weighted initial estimate and smoothness. It balances the numerical ranges of these two terms. Therefore, only its order of magnitude matters. The following samples are the haze removal results and trasmission estimates provided under λ=0.2, 0.02, 0.002. It shows that 0.02 might be a good choice. It can also be a number between 0.01 and 0.05, the difference will be unnoticeable.