METHOD FOR ELIMINATING BLOCK NOISE

PROBLEM TO BE SOLVED: To obtain a block noise eliminating method by which the distortion of a digital image is reduced and the sharpness of a digital image is maintained by limiting the application range of correction of a digital image to the distorted part and by which the memory capacity can be reduced by limiting referred data to only adjacent blocks. SOLUTION: The block positions of a block image after discrete cosine transform and of a block image adjacent to the above block image are detected, a DC capture 30 captures their DC coefficients and a new DC coefficient of the block image is obtained by a DC generator 40 on the basis of the DC coefficients. In the case of obtaining this new DC coefficient, the DC generator 40 obtains a parameter from the outside. Discrete cosine transform is applied twice to one block by using each of the new DC coefficients generated by the DC generator 40 and the original DC coefficient, a block memory 50 stores the result of the 1st discrete cosine transform using the original DC coefficient, and a selector 60 selects the result of the 1st or 2nd discrete cosine transform in matching with the output of the result of the 2nd discrete cosine transform using the new DC coefficient to the same block and provides the output of data 80.