Vision inspection system

A vision inspection system for inspecting unknown objects in relationship to a known object and for performing various visual tests on the unknown object if it is recognized as corresponding to the known object, comprising:

• A. vision sensing means for producing data representing the illumination values for viewed objects;
• B. means for receiving data from the vision sensing means and for storing the image of objects under test;
• C. means interconnected to the image storing means for viewing an imaged object;
• D. means interfaced with the viewing means for selecting at least three regions of the known imaged object;
• E. means interfaced with the image storing means for selecting regions on an unknown object, each region corresponding to one of the selected regions of the known object, each selected region on the unknown object having a size at least equal to the size of the corresponding region on the known object;
• F. means interfaced with the image storing means for determining and storing gradient values based upon the rate of change of illumination values for each selected region of the known and unknown objects, said gradient values for each selected region of the known object called a template and for each selected region of the unknown object called a gradient map;
• G. means interfaced with the gradient value determining means for determining the spatial and angular relationships between the templates;
• H. means interfaced with the gradient value determining means and spatial and angular relationship determining means for overlaying the templates with the gradient maps and for determining the correlation value between each template and the corresponding gradient map, with the separation of said templates based upon the previously determined spatial and angular relationships of said templates;
• I. means interfaced to the correlation value determining means for determining if each correlation value is greater than a predetermined value and if true, determining a composite correlation value of said correlation values;
• J. means interfaced with the gradient value determining and storing means for moving the templates over each corresponding gradient map so that the correlation value means and composite correlation value means determine their respective correlation and composite correlation values throughout the entire area of each gradient map;
• K. means interfaced with the composite correlation value determining means for determining the maximum composite correlation value, if any, and for determining the portions of each gradient map corresponding to this highest composite correlation value;
• and
• L. input/output (I/O) means interfaced with the maximum correlation value determining means for controlling the disposition of the test object based upon the presence or absence of a maximum composite correlation value;
• whereby the portions of each gradient map yielding the highest composite correlation value represent recognition of the object under test as corresponding to the known object.