CODING SYSTEM OF HANDWRITTEN SIGNAL

摘要

PURPOSE:To increase the accuracy of presumption and to ensure the highly efficient coding, by performing the presumption with use of the previous value and the value before the previous value. CONSTITUTION:The coordinate (x) of a point 1 which is produced at a terminal 11 of a tablet 10 by an input pen receives a PCM coding 50 and led to a multiplexing circuit 44. At the same time, x-3 and 0 are stored in memories 64 and 65 respectively via a switch 66. At the time of point 2, a presumption error x-2-(x-3+0) is calculated by a digital adder 61 and led to the circuit 44 by a DPCM coding circuit 74. At the time of point 3, x-2 and x-3 are stored in the memories 64 and 65 respectively with a switch 67 turned to the side (c). And 2X-2-x-3 is obtained at a digital adder 62 to x-1 and in the form of the value of presumption. Accordingly a presumption error x-1-(2x-2-x-3) is calculated by the adder 61 and DPCM coded 74 to be delivered 45 after a multiplication 44 with a code 200 corresponding to the coordinate (y).