The dynamic range of modern image sensors can exceed the range of a video monitor by an order of magnitude or more. This means that fast and intelligent range compression and image enhancement must be interposed between the sensor and display for effective visual communication. Digital hardware can enhance an image in real time, but the common method for range compression on digital hardware, linear filtering, can severely distort the image. Nonlinear methods must be used to prevent this distortion. In this paper, dynamic range compression of video images, at video rates, is demonstrated. An analog ASIC performs all of the necessary nonlinear image filtering at low power.
Andrew J. Moore,
"Nonlinear filtering for video dynamic range compression", Proc. SPIE 2239, Visual Information Processing III, (24 June 1994); doi: 10.1117/12.179278; https://doi.org/10.1117/12.179278