| 摘要 |
A contour encoding apparatus determines vertex points on the previous contour of the previous frame based on a polygonal approximation. A set of first approximation errors is calculated at a predetermined number of sample points on each first line segment between two vertex points, and a first set of discrete sine transform coefficients is obtained by discrete sine transforming the set of first approximation errors for each first line segment. Predicted vertex points are detected based on the vertex information and current contour of the current frame. A set of second approximation errors is calculated at the predetermined number of sample points on each second line segment between two predicted vertex points, and a second set of discrete sine transform coefficients is obtained by discrete sine transforming the set of second approximation errors for each second line segment. After determining a set of differences by subtracting the second set of discrete sine transform coefficients from the corresponding first set of discrete sine transform coefficients, the set of differences are encoded for transmission to thereby reduce the volume of transmission data. |
