ADAPTIVE DISCRETE COSINE TRANSFORM/INVERSE DISCRETE COSINE TRANSFORM DEVICE BASED ON ENERGY AND METHOD THEREFOR

摘要

PURPOSE: An adaptive DCT(Discrete Cosine Transform)/IDCT(Inverse DCT) device based on energy and a method therefor are provided to perform IDCT using only DCT coefficients of a 1*1, 3*3 or 4*4 size adaptively according to a compared result of energy per block with average energy for an input image, thereby remarkably reducing complexity and an amount of calculation. CONSTITUTION: An energy calculator(24) receives an image and divides the image into blocks of a predetermined size, and calculates energy per block and average energy to compare the energy per block with the average energy. A DCT unit(22) divides the inputted image into predetermined blocks for DCT. An image coefficient processor(26) receives and realigns DCT coefficients per block from the DCT unit(22) according to a compared result of the energy per block with the average energy received from the energy calculator(24). An IDCT unit(28) receives the DCT coefficients realigned in the image coefficient processor(26) to perform IDCT and recover the image.