Provided is an image processing device including a changing unit that changes a threshold value of intensity of each of points within an image, a first display control unit that controls displaying of points including an intensity value equal to or greater than the threshold value every time the threshold value is changed by the changing unit, a receiving unit that receives designation of one or a plurality of predetermined regions within a displayed image based on an operation of a user, a fixing unit that fixes the threshold value of each of the points within the designated predetermined region as a threshold value by the changing unit at a time of designation of the predetermined region, a second display control unit that controls displaying of points including an intensity value equal to or greater than the threshold value fixed by the fixing unit among the points within the predetermined region, and points including an intensity value equal to or greater than the threshold value to be changed by the changing unit among the points outside the predetermined region, in a case where there is one or the plurality of predetermined regions within the image.
