A motion estimating device for producing variable length coded motion vector.

摘要

A motion estimating device produces a variable length code motion vector (MV) which signifies the amount of movement of a block of pixel data. The motion vector can be used in a data compression system (Figure 1) to compensate for such motion of data when video data (CVS) is transmitted based on changes between successive frames. The motion estimating device (Figure 3) includes a mean error calculating circuit (100) that successively calculates the mean error between a small (N1 X N2) block of pixel data in a current picture (10) and a series of corresponding size blocks of data from a preceding reference picture (30), the reference picture blocks being shifted successively within a larger (M1 X M2) block (20) under the control of position coordinate signals (k, 1). Each mean error is computed by unit (40) and corresponding variable length code data (D1) is produced by unit (60). Data (D2) based on the difference between the previously computed vector (MV) from delay (70) and the current position coordinates (k,1) is computed by unit (80) in variable length code form. Unit (50) seeks and outputs a minimum value of the thus computed error signals to produce a variable length code vector (MV) with minimised data content.