Real-Time Photographic Local Tone Reproduction Using Summed-Area Tables

High dynamic range (HDR) rendering is becoming an increasingly popular technique in computer graphics. Its challenge consists in mapping the resulting images’ large range of intensities to the much narrower ones of the display devices in a way that preserves contrastive details. Local tone mapping operators effectively perform the required compression by adapting the luminance level of each pixel with respect to its local neighborhood. While they generate significantly better results when compared to global operators, their computational costs are considerably higher, which has prevented their use in real-time applications. This paper presents a real-time technique for photographic local tone reproduction that runs entirely on the GPU and is significantly faster than existing implementations that produce similar results. Our approach is based on the use of summed-area tables for accelerating the convolution of the local neighborhoods with a box filter and provides an attractive solution for HDR rendering applications that require high performance without compromising image quality.