| 摘要 |
<p>PURPOSE:To remove the influence of a ground pattern in a scanning area by deciding a slice level in accordance with the number of normalized black bits. CONSTITUTION:An input multivalued level pattern signal 10 is inputted to a black bit number counter circuit 5 to count the number of black bits at respective levels, and the counted result 13 is fed to a normalizing circuit 6 and a ground color level deciding circuit 8. The normalizing circuit 6 normalizes the number of black bits at respective levels by character string length and feeds the number of normalized black bits 14 to a character level deciding circuit 7, which compares the value of said fits 14 with a reference value and outputs a slice level for character recognizing slice level 15. The ground color level deciding circuit 8 compares the number of black bits before normalization with the reference value based on the said level 15, and outputs a slice level 16 where the ground color will not appear. A level deciding circuit 9 compares the slice level 15 with the slice level 16 and outputs the final slice level 17.</p> |
