Patent ID: 6658165
Filing Date: 2003-12-02
Classification: H04N

Abstract:
A contrast enhancing apparatus for a video signal, comprising:an algebraical converter for algebraically converting an inputted video signal; a wave filter for separating the algebraically converted video signal into a low frequency signal and a high frequency signal; a low frequency coefficient mapping unit for generating a level of a high frequency signal which is an output of the wave filtering unit and a level of the low frequency signal and a low frequency enhancing coefficient based on a user's adjustment; a high frequency coefficient mapping unit for generating a high frequency enhancing coefficient which is in inverse proportion to the low frequency enhancing coefficient; a first multiplier for multiplying the low frequency signal and the low frequency enhancing coefficient; a low frequency signal processing compensation unit for receiving an output of the low frequency mapping unit and an output of the first multiplier and compensating a low frequency level; a second multiplier for multiplying the high frequency signal and the high frequency enhancing coefficient; an adder for summing an output of the low frequency amplifying compensation unit and an output of the second multiplier; and an exponential converter for exponentially converting an output of the summing unit.