Using visibility cameras to estimate atmospheric light extinction

We describe methods for estimating the coefficient of atmospheric light extinction using visibility cameras. We use a standard haze image formation model to estimate atmospheric transmission using local contrast features as well as a recently proposed dark channel prior. A log-linear model is then used to relate transmission and extinction. We train and evaluate our model using an extensive set of ground truth images acquired over a year long period from two visibility cameras in the Phoenix, Arizona region. We present informative results which are particularly accurate for a visibility index used in long-term haze studies.