*2.2. Estimation of Atmospheric Light*

Atmospheric light **A** comprises pixels of the observed image for which *t*(**x**) = 0 in Equation (1); there is no direct light and the distance is infinity in Equation (2). In the outdoor image, this generally represents the intensity of the sky region. To estimate atmospheric light **A**, the highest luminance value is considered in the haze image **I** [3]. If an image contains a white object, the atmospheric light **A** is misestimated, and optimum atmospheric light **A** is estimated using dark-channel value [5]. Initially He et al. [5] determined the top 0.1% brightest pixels in the dark-channel image, and chose the highest intensity pixels from those same pixels in haze image **I**. Although this approach is useful because it can estimate atmospheric light **A** by ignoring small white object, the size is limited below the patch size.
