Imaging processing apparatus, camera system, image processing method, and program

An image processing method, the method comprising:

• imaging, within one field, at least a long accumulation image with a longer exposure time and a short accumulation image with a shorter exposure time;
• computing an exposure evaluation value from the long accumulation image to obtain a first long accumulation evaluation value;
• computing an exposure evaluation value from the long accumulation image according to a different method from that used to obtain the first long accumulation evaluation value to obtain a second long accumulation evaluation value;
• computing an exposure evaluation value from the short accumulation image to obtain a short accumulation evaluation value;
• obtaining a short accumulation target exposure time and short accumulation exposure control information from the short accumulation evaluation value and a first target level;
• obtaining a long accumulation evaluation value by synthesizing the first long accumulation evaluation value and the second long accumulation evaluation value in response to the short accumulation target exposure time using a predetermined method;
• acquiring long accumulation exposure control information from the long accumulation evaluation value and a second target level;
• and
• generating an image from the long accumulation image and the short accumulation image in response to the long accumulation exposure control information and the short accumulation exposure control information.

A non-transitory computer readable medium storing program code executable by a processing unit to perform operations comprising:

• imaging, within one field, at least a long accumulation image with a longer exposure time and a short accumulation image with a shorter exposure time;
• computing an exposure evaluation value from the long accumulation image to obtain a first long accumulation evaluation value;
• computing an exposure evaluation value from the long accumulation image according to a different method from that used to obtain the first long accumulation evaluation value to obtain a second long accumulation evaluation value;
• computing an exposure evaluation value from the short accumulation image to obtain a short accumulation evaluation value;
• obtaining a short accumulation target exposure time and short accumulation exposure control information from the short accumulation evaluation value and a first target level;
• obtaining a long accumulation evaluation value by synthesizing the first long accumulation evaluation value and the second long accumulation evaluation value in response to the short accumulation target exposure time using a predetermined method;
• acquiring long accumulation exposure control information from the long accumulation evaluation value and a second target level;
• and
• generating an image from the long accumulation image and the short accumulation image in response to the long accumulation exposure control information and the short accumulation exposure control information.