Vehicle camera calibration system

A camera calibration system for vehicular cameras, said camera calibration system comprising:

• a plurality of cameras disposed at a vehicle;
• wherein said plurality of cameras comprises a rear camera disposed at a rear portion of the vehicle and having a field of view rearward of the vehicle, a driver-side camera disposed at a driver side of the vehicle and having a field of view sideward and rearward at the driver side of the vehicle, and a passenger-side camera disposed at a passenger side of the vehicle and having a field of view sideward and rearward at the passenger side of the vehicle;
• wherein the fields of view of said rear camera and said driver-side camera overlap at a first overlapping region;
• wherein the fields of view of said rear camera and said passenger-side camera overlap at a second overlapping region;
• a control having an image processor operable to process image data captured by said rear camera, said driver-side camera and said passenger-side camera;
• wherein said image processor processes image data captured by said rear camera and said driver-side camera to determine at least one matching feature of an object present at the first overlapping region of the fields of view of said rear camera and said driver-side camera;
• wherein said image processor processes image data captured by said rear camera and said passenger-side camera to determine at least one matching feature of an object present at the second overlapping region of the fields of view of said rear camera and said passenger-side camera;
• wherein, while the vehicle is moving, said image processor processes multiple frames of image data captured by said rear camera and said driver-side camera to track the at least one matching feature of the object present in the first overlapping region of the fields of view of said rear camera and said driver-side camera;
• wherein, while the vehicle is moving, said image processor processes multiple frames of image data captured by said rear camera and said passenger-side camera to track the at least one matching feature of the object present in the second overlapping region of the fields of view of said rear camera and said passenger-side camera;
• wherein said control, responsive to image processing by said image processor of multiple frames of image data captured by said rear camera and said driver-side camera, determines motion of at least one matching feature of the object present in the first overlapping region of the fields of view of said rear camera and said driver-side camera and minimizes a first cost function of an error in the matching of the at least one feature of the object present in the first overlapping region of the fields of view of said rear camera and said driver-side camera;
• wherein said control, responsive to image processing by said image processor of multiple frames of image data captured by said rear camera and said passenger-side camera, determines motion of at least one matching feature of the object present in the second overlapping region of the fields of view of said rear camera and said passenger-side camera and minimizes a second cost function of an error in the matching of the at least one feature of the object present in the second overlapping region of the fields of view of said rear camera and said passenger-side camera;
• and
• wherein said camera calibration system uses the determined minimized first and second cost functions to refine calibration of said rear camera, said driver-side camera and said passenger-side camera using at least one feedback loop.

A camera calibration system for vehicular cameras, said camera calibration system comprising:

• a plurality of cameras disposed at a vehicle;
• wherein said plurality of cameras comprises a rear camera disposed at a rear portion of the vehicle and having a field of view rearward of the vehicle, a driver-side camera disposed at a driver side of the vehicle and having a field of view sideward and rearward at the driver side of the vehicle, and a passenger-side camera disposed at a passenger side of the vehicle and having a field of view sideward and rearward at the passenger side of the vehicle;
• wherein the fields of view of said rear camera and said driver-side camera overlap at a first overlapping region;
• wherein the fields of view of said rear camera and said passenger-side camera overlap at a second overlapping region;
• a control having an image processor operable to process image data captured by said rear camera, said driver-side camera and said passenger-side camera;
• wherein said image processor processes image data captured by said rear camera and said driver-side camera to determine at least one matching feature of an object present at the first overlapping region of the fields of view of said rear camera and said driver-side camera;
• wherein said image processor processes image data captured by said rear camera and said passenger-side camera to determine at least one matching feature of an object present at the second overlapping region of the fields of view of said rear camera and said passenger-side camera;
• wherein, while the vehicle is moving, said image processor processes multiple frames of image data captured by said rear camera and said driver-side camera to track the at least one matching feature of the object present in the first overlapping region of the fields of view of said rear camera and said driver-side camera;
• wherein, while the vehicle is moving, said image processor processes multiple frames of image data captured by said rear camera and said passenger-side camera to track the at least one matching feature of the object present in the second overlapping region of the fields of view of said rear camera and said passenger-side camera;
• wherein said control uses structure from motion of the ground structure moving through the fields of view of said rear camera and said driver-side camera while the vehicle is moving to generate a first three dimensional point cloud, and wherein said control uses structure from motion of the ground structure moving through the fields of view of said rear camera and said passenger-side camera while the vehicle is moving to generate a second three dimensional point cloud;
• wherein the generated three dimensional point clouds provide features that are present at respective overlapping regions of the fields of view of adjacent ones of said cameras;
• wherein said control, responsive to image processing by said image processor of multiple frames of image data captured by said rear camera and said driver-side camera, determines motion of matching features of the object present in the first overlapping region of the fields of view of said rear camera and said driver-side camera and minimizes a first cost function of an error in the matching of the features of the object present in the first overlapping region of the fields of view of said rear camera and said driver-side camera;
• wherein said control, responsive to image processing by said image processor of multiple frames of image data captured by said rear camera and said passenger-side camera, determines motion of matching features of the object present in the second overlapping region of the fields of view of said rear camera and said passenger-side camera and minimizes a second cost function of an error in the matching of the features of the object present in the second overlapping region of the fields of view of said rear camera and said passenger-side camera;
• and
• wherein said camera calibration system uses the determined minimized first and second cost functions to refine calibration of said rear camera, said driver-side camera and said passenger-side camera using at least one feedback loop.