Targetless vehicle camera calibration system

A method of calibrating a vehicular camera mounted at a vehicle moving along a vehicle assembly line, said method comprising:

• mounting a plurality of cameras at a vehicle moving along a vehicle assembly line, wherein each camera of the plurality of cameras comprises a CMOS imaging array;
• wherein one camera of the plurality of cameras comprises a rear camera mounted at a rear portion of the vehicle, and another camera of the plurality of cameras comprises a side camera mounted at a driver-side exterior rearview mirror assembly of the vehicle and another camera of the plurality of cameras comprises a passenger side camera mounted at a passenger-side exterior rearview mirror assembly of the vehicle;
• wherein the cameras, when mounted at the vehicle moving along the vehicle assembly line, have respective fields of view exterior of the vehicle that encompass a ground surface adjacent the vehicle assembly line;
• disposing a control at the vehicle moving along the vehicle assembly line, the control comprising an image processor;
• capturing frames of image data via the cameras as the vehicle moves along the vehicle assembly line;
• providing to the control frames of image data captured by the cameras as the vehicle moves along the vehicle assembly line;
• processing via the image processor frames of image data captured by the cameras as the vehicle moves along the vehicle assembly line;
• determining, via processing by the image processor of frames of image data captured by the cameras as the vehicle moves along a straight path portion of the vehicle assembly line, ground features of the ground surface adjacent to the vehicle assembly line;
• as the vehicle moves along the straight path portion of the vehicle assembly line, tracking the determined ground features over two or more frames of image data captured by each of the cameras;
• determining misalignment of the cameras via tracking the determined ground features over two or more frames of image data captured by the respective cameras as the vehicle moves along the straight path portion of the vehicle assembly line;
• responsive to determination of misalignment of at least one camera of the plurality of cameras, calibrating the at least one camera by using an assumption that the determined ground features tracked over two or more frames of image data captured by the at least one camera lie in a plane parallel to a planar portion of the ground surface adjacent the straight path portion of the vehicle assembly line;
• and
• wherein the steps of determining misalignment of the at least one camera and calibrating the at least one camera are performed without use of a target pattern at the vehicle assembly line.

A method of calibrating a vehicular camera mounted at a vehicle moving along a vehicle assembly line, said method comprising:

• mounting a camera at a vehicle moving along a vehicle assembly line, wherein the camera comprises a CMOS imaging array;
• wherein the camera, when mounted at the vehicle moving along the vehicle assembly line, has a field of view exterior of the vehicle that encompasses a ground surface adjacent the vehicle assembly line;
• disposing a control at the vehicle moving along the vehicle assembly line, the control comprising an image processor;
• capturing frames of image data via the camera as the vehicle moves along the vehicle assembly line;
• providing to the control frames of image data captured by the camera as the vehicle moves along the vehicle assembly line;
• processing via the image processor frames of image data captured by the camera as the vehicle moves along the vehicle assembly line;
• determining, via processing by the image processor of frames of image data captured by the camera as the vehicle moves along a straight path portion of the vehicle assembly line, ground features of the ground surface adjacent to the vehicle assembly line;
• as the vehicle moves along the straight path portion of the vehicle assembly line, tracking the determined ground features over two or more frames of image data captured by the camera;
• determining misalignment of the camera via tracking the determined ground features as the vehicle moves along the straight path portion of the vehicle assembly line;
• responsive to determination of misalignment of the camera, calibrating the camera by using an assumption that the determined ground features lie in a plane parallel to a planar portion of the ground surface adjacent the straight path portion of the vehicle assembly line;
• and
• wherein the steps of determining misalignment of the camera and calibrating the camera are performed without use of a target pattern at the vehicle assembly line.