NOISE ELIMINATING DEVICE, BAND DIVISION TYPE INVERSE DCT CIRCUIT, THEIR METHOD AND PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide a noise eliminating device for eliminating weak high frequency noise included in an image while suppressing the drop of image resolution feeling. SOLUTION: A band dividing part 11 divides inputted 8×8 two-dimensional DCT(discrete cosine transform) coefficients on which the weak high frequency noise is superimposed onto a low frequency region and a high frequency region and constructs respective blocks of 8×8 DCT coefficients. The respective DCT coefficient blocks are respectively outputted to an inverse DCT part 12 for low frequency components or an inverse DCT part 13 for high frequency components to be subjected to two-dimensional inverse DCT. An image including only low frequency components and an image including only high frequency components obtained in this way are recorded in a low frequency component image storing part 14 and a high frequency component image storing part 15, respectively. A weak noise eliminating part 16 makes a pixel value being equal to or smaller than a certain image threshold to be '0' with respect to an image read out from the storing part 15, and an adder 17 adds the image read out from the storing part 15 to a low frequency component image read out from the storing part 14.