Patent ID: 8487949
Filing Date: 2013-07-16
Classification: G09G

Abstract:
1. An image processing apparatus comprising: a conversion unit which converts RGB values of each pixel into ideal tristimulus values X, Y, and Z; a first histogram generation unit which obtains a first histogram by adding frequencies of the tristimulus values X, Y, and Z of one frame for each Y; a Y value selection unit which selects a characteristic Y value based on the first histogram; a chromaticity histogram generation unit which generates a chromaticity histogram for each Y value selected by the Y value selection unit; a color gamut information storage unit which stores, for each Y value, information of a color gamut representing a distribution of chromaticities displayable on a display panel; a chromaticity error count detection unit which obtains, for each backlight brightness, a frequency of a histogram out of a color gamut based on information of a color gamut corresponding to a value obtained by correcting the Y value selected by the Y value selection unit using a correction gain corresponding to the backlight brightness and the chromaticity histogram created by the chromaticity histogram generation unit; a lightness histogram creation unit which creates a lightness histogram from the RGB values of each pixel; a lightness error count detection unit which obtains, for each backlight brightness, a frequency of a histogram higher than a maximum tone based on a lightness corresponding to the maximum tone after correction using the correction gain corresponding to the backlight brightness and the lightness histogram created by the lightness histogram creation unit; a decision unit which decides a backlight brightness based on a number of chromaticity errors obtained by the chromaticity error count detection unit and a number of lightness errors obtained by the lightness error count detection unit; and a tone conversion unit which performs tone conversion of the RGB values of each pixel in accordance with the backlight brightness decided by the decision unit.