Abstract: A system and method recognize a user-defined model object within an image. The system and method recognize the model object with occlusion when the model object to be found is only partially visible. The system and method also recognize the model object with clutter when there may be other objects in the image, even within the model object. The system and method also recognize the model object with non-linear illumination changes as well as global or local contrast reversals. The model object to be found may have been distorted, when compared to the user-defined model object, from geometric transformations of a certain class such as translations, rigid transformations by translation and rotation, arbitrary affine transformations, as well as similarity transformations by translation, rotation, and scaling.