produced by the pecu for display on display 10 is a 2d array of points u v a given point in the image is related to the position of a corresponding point in a target the relationship between the image points and the corresponding 3d world coordinate x u2032 y u2032 z can be determined by a transformation matrix equation processed after calibration the accuracy of the overall calibration can be checked by measuring the position of a target within the field of view of the two sensors finding the range from the ultrasonic sensors determining its u v co ordinates in the image and using the camera and determining calibration parameters to estimate its position the transformation matrix equation can be optimized by artificial neural networks methods or statistical methods object detection may be the only function required from a sensing system detection is also a pre requisite for doing measurement and or identification thus the combined system must able to tell how many objects are present and must be able to match targets detected in the ultrasonic system with target in the vision system object detection is relatively straightforward with the ultrasonic system because of the amount of information in a video image object detection may be more difficult it is necessary to reduce this information to provide the data which is required to detect and measure the target components there are a variety of options in image processing available to do this with the ultimate aim generally of segmenting the image points into background and object points and labelling the different objects points techniques for image segmentation are well known and fully set out in the standard textbooks therefore an active object detection method can be developed where.