METHOD AND DEVICE FOR ENCODING CONTOUR

摘要

PROBLEM TO BE SOLVED: To reduce data volume by suitably masking discrete sine transformation(DST) coefficients in accordance with an output from a polygonal approximation process. SOLUTION: A masking control block 600 including a length calculation block 610 and a masking range setting block 620 calculates the length of each segment based on vertex information on a line L10 and generates a masking range setting signal for controlling a masking block 500 by using the length of respective segments and the number N (N is a positive integer) of segments. Each masked DST coefficient group corresponding to a DST coefficient group is generated by masking a prescribed part of each DST coefficient group or executing no masking in all of each DST coefficient group in accordance with the length and the number N. Each masked DST coefficient group is converted into a quantized DST coefficient group and each quantized DST coefficient group corresponding to each segment is encoded. Thus DST coefficients can be suitably masked.