Three-dimenisional object detection device

A three-dimensional object detection device comprising:

• a camera arranged to capture images rearward of a host vehicle equipped with the three-dimensional object detection device;
• and
• a computer;
• the computer being programmed to set a detection area for detecting a three-dimensional object rearward of the host vehicle;
• the computer being programmed to convert a viewpoint of the images obtained by the camera to create bird's-eye view images;
• the computer being programmed to detect a presence of a three-dimensional object within the detection area in which the bird's-eye view images obtained at different times are aligned, and difference waveform information is generated by counting and creating a frequency distribution of a number of pixels that indicate a predetermined difference having a difference threshold value or greater in a difference image of the bird's-eye view images that were aligned to detect the presence of the three-dimensional object within the detection area;
• the computer being programmed to set, as a reference image area, an image area that is different from the detection area and in which extraction of contour information of a subject is predicted;
• the computer being programmed to extract contour information of a subject in the reference image area and the detection area;
• the computer being programmed to calculate an amount of brightness of an image in the reference image area as a reference sharpness, based on the contour information extracted in the reference image area;
• and
• the computer being programmed to calculate an amount of brightness of an image in the detection area as a subject sharpness, based on the contour information extracted in the detection area,
• the computer calculating a final sharpness based on the reference sharpness and the subject sharpness, and setting the difference threshold value based on the final sharpness that was calculated.