Fast Filtering and Tone Mapping using Importance sampling

This paper examines the process of tone mapping and blooming, and then discusses its real-time implementation on current graphics hardware (GPU). The main contribution of this paper is a fast Gaussian filtering algorithm that significantly reduces the number of texture fetches and thus runs at interactive frame rates on the GPU. The reduction of the number of texture fetches is made possible by the rewriting of the filtering integral according to the concept of importance sampling. The proposed method can be used not only in tone mapping but also in other screen space camera effects as well, like bloom, glow or depth of field