Patent ID: 8275034

Claim:
A moving image encoding apparatus which selects a reference image and performs a prediction encoding by using a selected reference image, said apparatus comprising: a first image transformation unit adapted to transform image data corresponding to a current image into first image information, with reference to reference image data; a second image transformation unit adapted to inverse transform the first image information into reconstructed image data; a determination unit adapted to determine whether to use the reconstructed image data as new reference image data for subsequent prediction encoding or to discard the reconstructed image data; a calculator adapted to calculate, using the image data and the reconstructed image data, a peak signal-to-noise ratio (PSNR) indicating a degree of image degradation between the reconstructed image data and the image data; and a storage unit adapted to store the reconstructed image data, wherein, if a value of the PSNR is greater than or equal to a predetermined threshold, then said determination unit determines to use the reconstructed image data as the new reference image data, and wherein said determination unit sets a predetermined value which varies according to frame distance between the image data and the reconstructed image data stored in the storage unit, and determines to use the reconstructed image data as the new reference image data when a difference between the value of the PSNR and the predetermined value is greater than or equal to the predetermined threshold.