| 摘要 |
PURPOSE:To make judgement on degree of density in printing possible regardless of shape, size and quantity of printing characters by a method wherein the difference between image patterns cut out with two cut-out circuit at different slice levels is obtained, and processing is applied to correct the obtained difference. CONSTITUTION:An image scanner 1 converts printing characters into image signals 2 that are the electric signals, and outputs the converted signals. Two cut-out circuit 3 and 6 take the image signals 2 therein and cut them out at different slice levels and output them as binary coded signals 4 and 7. Image memories 5 and 8 respectively store the binary coded signals 4 and 7 as image patterns. The number of black dots in the image pattern outputted from the cut-out circuit 3 at higher slice level is made 'A', and the number of black dots in the image pattern outputted from the cut-out circuit 6 at lower slice level is made 'B'. A(D) obtained from the equation D=(A-B)/A is almost constant according to degree of density in printing, regardless of shape, size and quantity of the image patterns. A microprocessor judges the degree of such density by making calculation to obtain the value of D. |
