Abstract: A system for evaluating members or a family of similar devices by comparing images of a model device to the image of the member to be evaluated is disclosed. An image of the model device is first produced and stored in a memory. An image of the member to be evaluated is produced as the stored image of the model device is simultaneously reproduced. The images of the model and the member being evaluated are compared to generate a comparison signal related to the differences therebetween. The comparison signal is sampled at a predetermined rate, to produce a digital signal indicating sample points where the comparison signal exceeds a predetermined value. Statistical techniques are used to analyze the digital signal to determine which portions of this signal correspond to significant differences between the images of the model device and the member being evaluated.

Abstract: A system for evaluating similar object by comparing an image of the objects to be evaluated to the image of a similar object is disclosed. The system utilizes a TV camera to generate and store in a video memory an image of a reference member of the family of objects to be evaluated. This reference member has been previously evaluated by other means to determine that it meets predetermined specifications. An image of the member to be evaluated is then generated by focusing the TV camera on this member. Simultaneously, the stored image of the reference member is read from the video memory. These two images are compared to each other by an analog circuit to generate an analog signal related to the difference between these two signals. Sync signals are also generated by the memory to control the TV camera and a line counter which indicates which lines of the TV images are being compared.