PURPOSE: To provide non-weighted and weighted convolution filtering processes for decoding a bit map picture space expression for a self-clocking symbol shape code and tracing the number of ambiguity components (called as errors in occasion) met during the decoding of the code and their positions. CONSTITUTION: A bit map picture space expression for a self-clocking symbol shape code selected from (n) symbol sets is convoluted at least by (n) convolusion filters to obtain at least (n) convoluted pictures in accordance with weight, respective convoluted values are compared with each other, symbols are sorted by a symbol format, and decoding values are allocated in accordance with previously allocated data values. By the way, error detection can be related to or compared with error statistics based upon other decoding processing in order to improve the sureness of attained decoding.
CONVOLUTION FILTERING METHOD FOR DECODING SELF-LOCKING SYMBOL-SHAPE CODE