Image-classification-based global dimming algorithm for LED backlights in LCDs

• A simple luminance-and-CR-based image classification method is proposed.
• Image-classification-based backlight dimming algorithm.
• Image-classification-based and S-shape-based pixel compensation algorithm.
• Develop the prototype to give direct comparison on previous and proposed algorithm.

Backlight dimming can help LCDs reduce power consumption and improve CR. With fixed parameters, dimming algorithm cannot achieve satisfied effects for all kinds of images. The paper introduces an image-classification-based global dimming algorithm. The proposed classification method especially for backlight dimming is based on luminance and CR of input images. The parameters for backlight dimming level and pixel compensation are adaptive with image classifications. The simulation results show that the classification based dimming algorithm presents 86.13% power reduction improvement compared with dimming without classification, with almost same display quality. The prototype is developed. There are no perceived distortions when playing videos. The practical average power reduction of the prototype TV is 18.72%, compared with common TV without dimming.