| 摘要 |
PURPOSE:To sharpen only a real picture component excluding the noise component by providing a comparison means which compares the density levels between a notice picture elements and its peripheral picture elements to apply a sharpening procss if the density level difference is larger than the prescribed value, then a smoothing process if said density level is smaller than the prescribed value respectively. CONSTITUTION:Picture signals G5, G6, G8 and G9 of peripheral picture elements are supplied to an adder 120 from registers 5, 6, 8 and 9 and added together. The result of this addition is supplied to a 1/4 multiplier 121 to undergo the 1/4 multiplication to obtain the means value of density levels of peripheral picture elements (i-1, j), (i+1, j), (i, j-) and (i, j+1) respectively. This mean value is supplied to a subtractor 123 to obtain the difference (absolute value) of density levels between a notice picture element (i, j) and a picture signal G7. this level difference is supplied to a comparator 124 and compared with the comparison reference value R0. In this case, a sharpening process is carried out when a comparison result signal of ''1'' is supplied from the comparator 124. While a smoothing process is applied when a comparison result signal of ''0'' is supplied. Therefore, the value R0 of the comparator 124 can be varied to an optimum level according to the density level of the noise component. |
