Remarks on Hardware Implementation of Image Processing Algorithms
Image processing in industrial vision systems requires both real-time speed and robustness. Modern computers, which fulfill the first demand, are sensitive to hard industrial environment conditions and require considerable amounts of energy. Programmable logic chips are available, which can realize many simple, still time-consuming operations in a parallel or a pipelined manner. The paper discusses particular features of the pipelined architecture and presents selected techniques of implementing early image processing procedures in hardware.
Our aim is to discuss three approaches to the detection of defects in continuous production processes, which are based on local methods of processing image sequences. These approaches are motivated by and applicable to images of hot metals or other surfaces, which are uniform at a macroscopic level, when defects are not present. The first of them is based on the estimation of fractal dimensions of image cross-sections. The second and third approaches are compositions of known techniques, which are selected and tuned to our goal. We discuss their advantages and disadvantages, since they provide different information on defects. The results of their testing on 12 industrial images are also summarized.