PRODUCT APPEARANCE INSPECTION METHODS AND APPARATUS EMPLOYING LOW VARIANCE FILTER

摘要

Images such as product images are identified as substantially similar to one or more reference images by finding pixels which have substantially the same value or values in all or substantially all of the reference images. Image erosion and/or dilation may be used in processing the reference image data to help identify pixels which can always be expected to have the same value in all acceptable images. The values associated with the corresponding pixels in a product image are combined and compared to an expected value. The product image is identified as substantially similar to the reference image or images only if the combined values from the product image compare favorably with the expected value.