Browsing by Author "Liao, Cheng-Yu"

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Dynamic backlight gamma on high dynamic range LCD TVs
(2008-06-01)
Lin, Fang-Cheng
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Huang, Yi-Pai
;
Liao, Lin-Yao
;
Liao, Cheng-Yu
;
Shieh, Han-Ping D.
A high dynamic range liquid crystal display (HDR-LCD) can enhance the contrast ratio of images by utilizing locally controlled dynamic backlight. We studied the HDR-LCD as a dual-panel display: a backlight module and a liquid crystal (LC) cell. As the gamma of the LC signal, the backlight module was also endowed with a gamma function to control the contrast ratio of HDR images. The inverse of a mapping function (IMF) method proposed as a dynamic gamma mapping curve for the backlight module, has been demonstrated to further improve in HDR image quality. By implementing the IMF method on a 37 '' HDR-LCD TV with 8 x 8 backlight zones, the image contrast ratio can reach similar to 20000:1 while maintaining high brightness, clear image detail, and an average power reduction of 30%.
Inverse of mapping function (IMF) method for image quality enhancement of dual-panel displays
(2007)
Liao, Cheng-Yu
;
Lin, Fang-Cheng
;
Liao, Lin-Yao
;
Huang, Yi-Pai
;
Shieh, Han-Ping D.
A high dynamic range liquid crystal display (HDRLCD) can much.enhance the contrast ratio of images upon the locally controlled backlight. A novel method, inverse of mapping function (IMF), was demonstrated to further improve the HDR image quality from the information of each frame. By using IMF, the contrast ratio of image in a 37 '' HDR-LCD TV was successfully improved to similar to 20,000:1 with high brightness and clear image details. Besides, for mass production, the backlight of the 37 '' HDR-LCD TV was divide into 8x8 zones to lower the cost and hardware computation complexity.