Patent ID: 7181088

Claim:
A method for constructing a Gamma table to perform Gamma correction according to the Gamma table so as to obtain a Gamma relationship of an input pixel datum, wherein the pixel datum is represented by a binary datum of J bits and J is a positive integer, the method comprising the steps of: a) constructing a Gamma table, wherein the Gamma table comprises a plurality of sampling pixel data and the corresponding Gamma relationship for every sampling pixel datum; each of the sampling pixel data is a binary datum of J bits; and the Gamma table is constructed by at least the steps of: a1. selecting (2 M +1) major sampling pixel data from a Gamma curve, wherein the (2 M +1) major sampling pixel data are sequentially numbered from a first major sampling pixel datum to a (2 M +1)-th major sampling pixel datum, and further divide the Gamma curve into 2 M major segments, sequentially numbered from a first major Gamma segment to the 2 M -th major Gamma segment, where M is a positive integer smaller than J; a2. using every two adjacent major sampling pixel data to form 2 M major sampling lines, sequentially numbered from a first major sampling line to a 2 M -th major sampling line, wherein the n-th major sampling line corresponds to the n-th major Gamma segment where n is a positive integer ranging from 1 to 2 M ; a3. determining a maximum difference D n between the n-th major sampling line and n-th major Gamma segment; a4. according to the maximum difference D n , selecting (2 Rn −1) minor sampling pixel data from the n-th major Gamma segment, which are sequentially numbered from a first minor sampling pixel datum to a (2 Rn −1)-th minor sampling pixel datum, wherein R n is a value corresponding to the n-th major sampling pixel datum and the n-th major Gamma segment; and a5. storing the Gamma relationship of these major and minor sampling pixel data in the Gamma table; and b) executing Gamma correction according to the Gamma table to obtain the Gamma relationship of the input pixel datum, comprising the following steps: b1. selecting the a-th major sampling pixel datum according to first M bits of the input pixel data, wherein a is a positive integer of 1 to 2M; b2. selecting corresponding b-th and (b+1)-th minor sampling pixel data of the a-th major sampling pixel datum, according to (M+1)-th to (M+R a )-th bits of the input pixel data, wherein ‘b’ is a positive integer of 1 to R a ; and b3. obtaining the Gamma corresponding relationship of the input pixel datum via interpolation using the b-th and the (b+1)-th minor sampling pixel data.