1. An image processing device configured to generate disparity information from a first image and a second image, wherein the first image is captured by a first capture unit and the second image is captured by a second capture unit, the image processing device comprising: a disparity detector configured to detect a first disparity information of a specific pixel or a specific pixel block of the second image by correlating the specific pixel or the specific pixel block of the second image with each of pixels or each of pixel blocks of a first detection range having a predetermined detection width in the first image, wherein the disparity detector is configured to detect second disparity information of the specific pixel or the specific pixel block of the second image more than once by specifying a start point of a second detection range having the predetermined detection width in the first image, the second detection range being different from the first detection range, and correlating the specific pixel or the specific pixel block of the second image with each of pixels or each of pixel blocks of the second detection range that has the predetermined detection width from the start point.