Abstract: In an example embodiment, rather than a single calibration object, a plurality of calibration objects are placed within the field of view of an inspection camera at the same time. Each of the calibration objects is or includes a semi-spherical reflective object having known sizes. During a calibration process, the distance between a light source and camera may be determined by activating the light source and capturing an image of how the light source bounces off each of the calibration objects, and more particularly the location on each of the calibration objects that the light source appears to reflect from. This allows the angle that the light source strikes each calibration object to be calculated, and these angles can then be used to determine the distance between the light source and the camera.

Abstract: In an example embodiment, a calibration phase is performed where a calibration object is sent through the system and multiple images of the calibration object are taken. From these images, the direction and speed of the calibration object can be computed as well as the distance between the calibration object and the camera. From these three pieces of information, a three-dimensional offset vector is created. This three-dimensional offset vector can then be applied during a photometric stereo process to align the object in the different images so that the orientation and graduation of the surface can be accurately calculated.

Abstract: In an example embodiment, rather than a single calibration object, a plurality of calibration objects are placed within the field of view of an inspection camera at the same time. Each of the calibration objects is or includes a semi-spherical reflective object having known sizes. During a calibration process, the distance between a light source and camera may be determined by activating the light source and capturing an image of how the light source bounces off each of the calibration objects, and more particularly the location on each of the calibration objects that the light source appears to reflect from. This allows the angle that the light source strikes each calibration object to be calculated, and these angles can then be used to determine the distance between the light source and the camera.