Abstract: A backlight for a LCD comprises two or LED arrays, each corresponding to a respective color channel. A control circuit controls the supply current to each LED array separately based on the content of a displayed image to reduce the current consumption of the backlight. The control circuit generates separate histograms of transmittance values for each of two or more color channels in the image, and stretches the histograms for the two or more color channels by respective stretching factors to generate a stretched image. The stretched image is displayed on the LCD. The control circuit further control the current supply to the two or more LED arrays in the backlight to reduce a brightness of light emitted by the two or more LED arrays in dependence on respective stretching factors for the corresponding color channel.

Abstract: A backlight for a LCD comprises two or LED arrays, each corresponding to a respective color channel. A control circuit controls the supply current to each LED array separately based on the content of a displayed image to reduce the current consumption of the backlight. The control circuit generates separate histograms of transmittance values for each of two or more color channels in the image, and stretches the histograms for the two or more color channels by respective stretching factors to generate a stretched image. The stretched image is displayed on the LCD. The control circuit further control the current supply to the two or more LED arrays in the backlight to reduce a brightness of light emitted by the two or more LED arrays in dependence on respective stretching factors for the corresponding color channel.

Abstract: Provided is a method of Content Adaptive Backlight Control (CABC) for use in an electronic mobile device for improving a quality of an image. The electronic mobile device comprises at least one display i.e. a Liquid Crystal Display (LCD) for showing the image. The content of the image is shown on the display by a plurality of pixels. The electronic mobile device is adapted to establish a light level of light being ambient of the electronic mobile device, and to stretch a histogram of the image whereby a part of the plurality of pixels is brought into saturation. When the ambient light level is below a first threshold, the stretching of the histogram is decreased, whereby the part of the plurality of pixels brought into saturation is decreased and the quality of the image is improved.