Image capturing apparatus, image capturing method, and program

An image capturing method comprising:

• setting a first exposure time and a second exposure time shorter than the first exposure time, the second exposure time being an exposure time obtained by dividing the first exposure time by an integer m where m is an integer equal to or larger than 2;
• controlling an imaging sensor to capture frames successively by repeatedly performing exposure including at least exposure for one frame having the first exposure time and exposure for m frames having the second exposure time as one set;
• acquiring image data of each frame from the imaging sensor;
• generating image data of an average frame that is an average of pieces of image data of the m frames having the second exposure time in the one set;
• generating a composite frame for recording or displaying a motion picture of an extended dynamic range according to image data of the one frame having the first exposure time and the image data of the average frame;
• calculating a proportion of blown-out highlight pixels in at least one of the image data of the one frame having the first exposure time or image data of one frame having the second exposure time;
• and
• making an increase change or a decrease change to the integer m in a next set on the basis of the proportion of blown-out highlight pixels.

A non-transitory computer readable medium for storing a program causing a computer to perform an image capturing method comprising:

• setting a first exposure time and a second exposure time shorter than the first exposure time, the second exposure time being an exposure time obtained by dividing the first exposure time by an integer m where m is an integer equal to or larger than 2;
• controlling an imaging sensor to capture frames successively by repeatedly performing exposure including at least exposure for one frame having the first exposure time and exposure for m frames having the second exposure time as one set to control exposure;
• acquiring image data of each frame from the imaging unit;
• generating image data of an average frame that is an average of pieces of image data of the m frames having the second exposure time in the one set;
• generating a composite frame for recording or displaying a motion picture of an extended dynamic range according to image data of the one frame having the first exposure time and the image data of the average frame;
• calculating a proportion of blown-out highlight pixels in at least one of the image data of the one frame having the first exposure time or image data of one frame having the second exposure time;
• and
• making an increase change or a decrease change to the integer m in a next set on the basis of the proportion of blown-out highlight pixels.