Abstract: An apparatus for providing a two-dimensional image of a three-dimensional object illuminates the surface of the object using an illumination source. Portions of the surface are imaged through an aperture in a plate onto a portion of a matrix sensor. The object is rotated about its principle axis while being simultaneously translated, and, at the same time the aperture is also rotated. By synchronizing these translational and rotational movements, successive portions of the object surface can image onto respective successive portions of the matrix sensor, thereby providing an improve two-dimensional image of the surface of the object.

Abstract: This invention provides a method and apparatus (100) for detecting small glass particles (12) in bottles (1) filled with beer (10). The beer (10) is caused to rotate with respect to the bottle (1), and successive images are obtained from the bottle by means of a CCD-camera (40) which is arranged such that its optical axis (41) makes an angle &agr; of about 135° with the axis (13) of the bottle (1), which is illuminated from below. The successive images are subtracted from each other to detect refracted light emanating from glass particles. These measurements are repeated a plurality of times. The invention thus offers an improvement in sensitivity and reliability of a detecting method. An apparatus (100) comprises a carousel (103) with a plurality of cameras dedicated to a single bottle. A system is described to reduce costs by having eight cameras share one image processing unit.