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Two approaches to derive LED driving signals for high‐dynamic‐range LCD backlights
Author(s) -
Li Feng,
Feng Xiaofan,
Sezan Ibrahim,
Daly Scott
Publication year - 2007
Publication title -
journal of the society for information display
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.578
H-Index - 52
eISSN - 1938-3657
pISSN - 1071-0922
DOI - 10.1889/1.2825109
Subject(s) - backlight , computer science , high dynamic range , liquid crystal display , brightness , dynamic range , computer vision , high dynamic range imaging , computation , artificial intelligence , algorithm , optics , physics , operating system
— The LED‐array backlight technique dramatically enhances the dynamic range of an LCD and hence extends its ability to present images with high reality. This is achieved by modulating LEDs individually, thus providing an area‐adaptive backlight for the display. The spatial overlap of light from the LED (crosstalk) occurs due to the diffusion screen placed between the backlight and LCD layer. However, the crosstalk is not only a blessing for supplying high brightness but is also a curse for causing potential artifacts, making the derivation of an LED driving signal a challenging task. This paper formulates the problem into two mathematical models: an iterative de‐convolution approach and a linear optimization approach. Algorithms for solving these two models are provided. The first approach provides instantaneous and satisfactory results except for high‐intensity highlights in the image. The linear optimization method conquers this drawback, but requires much more computation, possibly requiring preprocessing of the target, and also introduces undesired artifacts. These two approaches are extensively evaluated by building an image database composed of 161 high‐dynamic‐range images.