An image processing device includes a memory storing a program, and at least one processor that executes the program. The processor sets an exposure condition for video imaging, acquires an image of the video imaged under the exposure condition, and calculates a brightness distribution from the image. The exposure condition includes a first exposure condition for causing the imaging device to capture an image using a first exposure value, and a second exposure condition causing the imaging device to capture an image using an exposure value higher than the first exposure condition and/or causing the imaging device to capture an image using a lower exposure value than the first exposure condition. The processor sets the first exposure condition or sets the first and the second exposure condition, based on the brightness distribution of the image captured under the first exposure condition after the first exposure condition is set.