| 摘要 |
PROBLEM TO BE SOLVED: To realize coding bit map data without any noise by detecting a correlation of received bit map data in the vertical direction so as to detect and eliminate the noise added to the received bit map analog data. SOLUTION: When quantized bit map data are at a background video transmission level of '4', an AND circuit 215 provides an output of '1', and when bit map data of one preceding line delayed by a 1-line memory 210 are less than level 4, an AND circuit 218 provides an output of '1'. Furthermore, when bit map data of two preceding line delayed by a 1-line memory 211 are less than background video transmission level 4, an AND circuit 222 provides an output of '1'. Then an AND circuit 223 ANDs outputs of the AND circuits 215, 218, 222 to take correlation in the vertical direction and to detect noise, and the detected noise is outputted forcibly as a level 4 by AND circuits 227, 229, 230 and a OR circuit 228. |
