| 摘要 |
PROBLEM TO BE SOLVED: To obtain an easy-to-observe picked up image having no halation even in the case of picking up the image of a treatment tool. SOLUTION: A gate signal generation circuit 29 outputs a gate signal for performing peak photometry at a center part and average photometry at a periphery part in an image pickup range. A clip circuit 33 clips an inputted video signal only in terms of an average photometry area and gives it to an integration circuit 34. The circuit 34 integrates the video signal equivalent to a peak photometry area by a comparatively large coefficient and the video signal equivalent to the average photometry area by a comparatively small coefficient. Thus, little influence is exerted on photometric results by luminance by the treatment tool at the periphery part, and a high-luminance affected part at the center part can be observed with sufficient brightness by the peak photometry. Furthermore, when the existence of the treatment tool is shown by a color discrimination signal in the peak photometry area, a mask circuit 31 masks such a part. Thus, the photometry is not adversely influenced by the treatment tool in the peak photometry area.
|
