THREE-DIMENSIONAL OBJECT DETECTION DEVICE

This three-dimensional object detection device is provided with: a three-dimensional object detection means (32, 33, 34) for generating difference waveform information by counting the number of pixels indicating a difference at a difference threshold value or higher in a difference image in which bird's-eye view images at different times have been aligned, and detecting a three-dimensional object based on the difference waveform information; a reference image area setting means (35) for setting, as a reference image area, an area that is different from the detection area and in which extraction of contour information of a subject is predicted; a contour information detection means (35) for extracting the contour information of the subject; a reference sharpness calculation means (35) for calculating a reference sharpness based on the contour information detected in the reference image area; and a subject sharpness calculation means (35) for calculating a subject sharpness based on the contour information detected in the detection area. The three-dimensional object detection unit (32, 33, 34) calculates a final sharpness based on the reference sharpness and the subject sharpness, and sets the difference threshold value based on the calculated final sharpness.