Abstract: A method of determining the roll angle of a camera mounted on a host vehicle includes: a) defining Cartesian axes in the real world and corresponding axes in the camera imager; b) from an image taken from the camera, determining the co-ordinates of the two points (P1, P2) of the real world, in the imager of the camera ((x I,1, y I,1), (x I,2, y I,2)); c) determining the difference (D) in the coordinates of the points in a horizontal World plane in one axis (Xw,1?Xw,2), using corresponding co-ordinate system as in step b); and d) determining the roll angle ? of a camera located on a host vehicle from the following formula ?=[D/h?(c2/a2?c1/a1)]/[(a2d2?b2c2)/a22?(a1d1?b1c1)/a12], where a1 and a2 are found from the following, where i=1,2 represents the two points (P1, P2): ai=sin ?*f+cos ?*yI,i; bi=?cos ?*xI,i ci=?cos ? cos ?*f+sin ?*xI,i+cos ? sin ?*yI,I di=?cos ? sin ?*xI,i+sin ?*yI,i where for ? is the known value of fixed tilt angle, ? is the known value of fixed pan angle and h is the known fixe

Abstract: A method of determining the roll angle of a camera mounted on a host vehicle includes: a) defining Cartesian axes in the real world and corresponding axes in the camera imager; b) from an image taken from the camera, determining the co-ordinates of the two points (P1, P2) of the real world, in the imager of the camera ((x I,1, y I,1), (x I,2, y I,2)); c) determining the difference (D) in the coordinates of the points in a horizontal World plane in one axis (Xw,1?Xw,2), using corresponding co-ordinate system as in step b); and d) determining the roll angle ? of a camera located on a host vehicle from the following formula ?=[D/h?(c2/a2?c1/a1)]/[(a2d2?b2c2)/a22?(a1d1?b1c1)/a12], where a1 and a2 are found from the following, where i=1,2 represents the two points (P1, P2): ai=sin ?*f+cos ?*yI,i; bi=?cos ?*xI,i ci=?cos ? cos ?*f+sin ?*xI,i+cos ? sin ?*yI,I di=?cos ? sin ?*xI,i+sin ?*yI,i where for ? is the known value of fixed tilt angle, ? is the known value of fixed pan angle and h is

Abstract: A method of calibrating an image acquiring device which is arranged at a vehicle at an installation height, assumes a provisional value for the installation height and a defined path length in a road plane. The measurement path is projected onto the image plane by means of a perspective projection using the provisional value of the installation height in order to determine measurement positions in the image which correspond to a path start and to a path end of the measurement path. An object located at two measurement positions at two different times is identified in consecutively acquired images. A calculated path length of the measurement path is determined from the time difference between the different times and the speed of the motor vehicle. An actual value for the installation height is determined using a comparison of the defined path length with the calculated path length.