Patent ID: 7142598
Filing Date: 2006-11-28
Classification: H04N

Abstract:
1. An adaptive DCT/IDCT (Discrete Cosine Transform/Inverse Discrete Cosine Transform) apparatus based on energy in a coding unit of a MPEG4/H.263 video coder, said apparatus comprising: an energy calculator for receiving an input image, dividing the input image into blocks of predetermined size, calculating energy values for respective blocks and a mean energy value for the input image using the following equation where P MB is an energy value of the image, S is|ƒ(x,y)−E(ƒ)|, ƒ(x,y) is a pixel value of the image, E(ƒ) is a mean value of image pixels, and R is a size of the image, and comparing the energy values of the blocks with the mean energy value; a DCT unit for dividing the input image into blocks corresponding to the blocks of the energy calculator, and performing a DCT operation on the divided blocks; an image coefficient processor for receiving DCT coefficients for respective blocks from the DCT unit according to a result of the comparison of the block's energy value and the mean energy value, and recasting the DCT coefficients; and an IDCT unit for receiving recasted DCT coefficients from the image coefficient processor, performing an IDCT operation on the recast DCT coefficients, and creating a restored image.