Non-uniform backlighting computation for high dynamic range displays

In recent years, non-uniform LED based backlighting techniques have been used to build display prototypes and products with extremely high dynamic range, thus making possible to show video content with very high fidelity. These displays have two modulation channels: a low resolution LED layer that provides non-uniform backlighting, and a high resolution LCD front panel for color. Unfortunately, displaying an HDR image on such screens is not straightforward because the lower resolution of the LED layer and the cross-talk between LEDs make not possible to individually control the output of each pixel. Using the wrong backlighting results in low image quality and may even lead to visual artifacts such as false contouring and visible LED patterns. In this paper, we characterize the LED/LCD display using a general model and formulate the backlighting computation as an optimization problem. We further propose an iterative algorithm to solve the optimization problem. Compared to existing methods, our model is more precise and provides better image quality on the same display device.