| 摘要 |
PROBLEM TO BE SOLVED: To provide an image processing device which secures an effective exposure time and removes dark current noise stably regardless of a change in the temperature of an imaging element even when a highly sensitive imaging element is used. SOLUTION: The image processing device 4 has an average value computing circuit 41 as a means of computing an imaging condition for computing a dependency value on the imaging condition. This circuit computes an average picture element value for one frame of a picture element determined as a lightproof area by a lightproof part determining signal from a dark current distribution tentative storage memory 39. The device also has a multiplication circuit 42 as a means for computing noise to compute a noise pattern under the imaging condition. This circuit multiplies a reference dark current value from the memory 39 with the average picture element value computed by the circuit 41, and converts the value to dark current noise associated with the temperature of a CCD 23 in operation. The device also has a subtraction circuit 33 which subtracts the dark current converted by the circuit 42 from an image signal outputted from an A/D conversion circuit 32, and removes a noise pattern caused by the dark current. COPYRIGHT: (C)2004,JPO
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