Morphological transformations are applied to industrial inspection problems. A real time optical architecture to implement morphological transformations such as erosion, opening, closing, and skeletonization is described and analyzed. The first real time optical laboratory results of erosion and opening are presented for locating string in tobacco.

Many uses for the Hough transform (HT) require only several theta slices, not the entire 2-D Hough space. A new holographic optical architecture is advanced to achieve this in parallel. The computer-generated holograms and holographic optical elements used are discussed, and laboratory results are provided. As a case study, we consider determining printing skew and other defects on cigarette packs. We also discuss how these holograms can produce the entire 2-D HT space.

Coherent optical processors for product inspection are discussed, and data from a case study are presented. An optical processor that produces both Fourier and Hough transform data is presented. The Fourier transform data are wedge /ring sampled to produce in -plane distortion-invariant features to determine the product's attribute (good or defective) and its orientation. Hough transform data are used for new quantitative mensuration information on good products. In one case, optical Hough transforms are quantitatively shown to yield more consistent results than do digital realizations.

Real-time optical inspection techniques are discussed and implemented on laboratory systems. Specifically, we show how Fourier transform and Hough transform data can be used in an industrial inspection application. We also discuss how a 1-D synthetic discriminant function is used for label inspection. Real-time optical Hough transform inspection data using a 2-D spatial light modulator is presented and discussed. A color liquid crystal television (LCTV) is used as the input transducer to provide real-time data. New methods to process color image data on color LCTVs are detailed. A new high speed acoustooptic architecture to generate Hough transform slices is also detailed. A specific product inspection case study is discussed.

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