Abstract: An image acquisition system is arranged to optimize the information in an acquired image. Parameters associated with the system, such as any of the lens aperture, the lens focus and image intensity, are adjusted. Incoming image data is processed to determine the entropy of the image and with this information the aperture can be optimized. By determining the dynamic range of the scene the black and white levels thereof can be identified and the gain and offset applied to the image adjusted to minimize truncation distortion. Specular highlights can be detected by calculating the ratio of changes in maximum and minimum intensities between different but related images.

Abstract: The flatness of at least a portion of a substantially planar surface (16) is measured by illuminating the surface through a beam splitter (12) incorporating a grid (13) or other patterned shield. The light pattern reflected from the surface (16) is directed by way of a reflector (14) back through the beam splitter (12) and thus through the grid (13). The image exiting the beam splitter (12) has characteristics representative of the flatness of the surface.