DCT BASED SUBPIXEL ACCURACY MOTION ESTIMATION UTILIZING SHIFTING MATRIX

摘要

The present invention relates to a method to estimate subpixel unit motion based on discrete cosine transform (DCT) by using a shifting matrix, to use a shifting matrix in a frequency domain, so as to estimate motion of subpixel accuracy based on DCT. According to the present invention, a method to estimate motion of a 1/4 subpixel unit for moving image encoding comprises the following steps: performing DCT about an inputted image frame; and estimating motion in a frequency domain, in order to acquire an estimation block having a minimum matching error with respect to a current block through block matching between a DCT-performed current image frame and a previous image frame. In the step of estimating the motion in the frequency domain, the estimation block is acquired through a horizontal/vertical shifting matrix applying image interpolation of a 1/4 subpixel unit using a three dimensional interpolation function, and matrix operation using a DCT coefficient matrix of four blocks around the estimation block in a search range of the previous image frame.