This paper proposes an automatic identification method of surface defects on the VLSI wafer (which has repeated patterns on each chip). The applied system of this method is described, using a VLSI wafer as an example of its practical use. This inspection system utilizes boundary extraction with improved S/N ratio, and a defect detection algorithm obtained by matching two corresponding parts of these repeated pattern boundaries.
Making high speed the circuitry of the above process, this system can be put to practical use.

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A new concept of noise reducer, where restrictions on noise are taken into consideration, is described. As an example, a method of color noise reduction of a triode TV camera is explained in detail. The principle is as follows.
As thermal noises of the components are not independent each other, the luminance component of a NTSC signal contains little noise. Thus it is sufficient to consider color noise reduction only.
Simple color noise reduction is low pass filtering, but causes degradation around the boundaries of different color. In order to avoid such degradation, parameters of the low pass filter should be controlled adaptively depending on the picture content. Major problem in such a method is how to detect color edges, since color signals change not only at edges but by noise. The performance of the proposed method, where color edges are detected using the luminance signal, is confirmed by simulation.

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