Abstract: A method and apparatus is provided which addresses the drawbacks of the prior art and which incorporates two separate imaging devices, one near-infrared and one mid-infrared imaging device which simultaneously capture images of the passing objects. The background information is removed and images of the objects remain. A spherical optical transform and a defect preservation transform preserve any defect levels on objects and compensate for the non-lambertian gradient reflectants on spherical objects at their curvatures and dimensions.

Abstract: A method and apparatus is provided which incorporates two separate imaging devices, one near-infrared and one mid-infrared imaging device which simultaneously capture images of the passing objects. The background information is removed and images of the objects remain. A spherical optical transform and a defect preservation transform preserve any defect levels on objects and compensate for the non-lambertian gradient reflectance on spherical objects at their curvatures and dimensions. The processed images provided by the mid-infrared camera are subtracted from the images provided by the near-infrared camera to produce an image of just defects which are analyzed to produce the separation or sorting control signals based on defect rejection decisions and user parameters to signal appropriate mechanical actions (driver commands) to separate objects with defects from those that do not contain defects, or to sort or categorize objects based on the amount, type, size, or character of the defects.