Patent ID: 7924923
Filing Date: 2011-04-12
Classification: H04N

Abstract:
1. A motion estimation method adaptive to change in illumination, comprising the steps of: (a) generating a current frame pattern block for a current frame block and a reference frame pattern block for a reference frame block; (b) calculating the sum of absolute differences (SAD) for candidate pattern blocks corresponding to the current frame pattern block among reference frame pattern blocks and determining each candidate pattern block corresponding to the SAD satisfying a predetermined condition among the calculated SAD as a motion vector; (c) encoding the current frame block, by generating a residual signal using a difference signal between the candidate pattern block corresponding to the motion vector and the current frame pattern block then performing discrete cosine transform and quantization to the residual signal with a predetermined encoding mode; and (d) adding flag information indicating the addition of a mean pixel value applied to the encoded current frame block and identification information on the encoding mode as header information corresponding to the encoded current frame block; wherein the addition of a mean pixel value to be applied to the current frame block is identified by the flag information, wherein step (a) includes the steps of: calculating a mean brightness value of the current frame block and a mean brightness value of the reference frame block; and generating the current frame pattern block by subtracting the mean brightness value of the current frame block from brightness values of the current frame block and generating the reference frame pattern blocks by subtracting the mean brightness value of the reference frame block from brightness values of the reference frame block.