Fujitsu Corporation

Hiromichi Iwase

Takashi Toriu

Tohru Ozaki

Shigeru Sasaki

Toshiyuki Gotoh

This invention relates to a method and apparatus for extracting contour lines from a pattern obtained in image processing. The disclosed method and apparatus makes it possible to obtain the contour lines in real-time and, moreover, can be easily incorporated into hardware. To achieve these objects, a invention applies the simplified discrimination method for selecting pixels, which form the pattern contour, wherein each pixel is examined within groups of pixel, i.e. X-axis and Y-axis groups. The magnitude of a gray level gradient of each pixel is compared with those of neighboring pixels located in either direction of X-axis group or Y-axis. The pixel which has the maximum magnitude of gray level gradient among those of adjacent pixels is discriminated from each group as contour date. This discrimination method is simple and remarkably improved. When contour lines for two groups are combined, the pattern contours can be easily obtained.

Method and apparatus for extracting pattern contours in image processing

An image processing system mainly used in an image verification system for detecting and correcting distortion of an input image includes the following devices; an image memory for storing a digitized image before, during, and after correction, a working memory for temporarily storing intermediate data of the image on correction, density level extension devices for extending the density level or gradation of the image by repeatedly reading out the contents of the image memory and the working memory by using a matrix window containing picture elements of the image, a density slope detection device for detecting the extended density level and calculating a density slope or gradient by using the matrix window, and a correction device for correcting density distribution and line width of the image based on the extended density level and the calculated density slope.

Image processing system

An apparatus for evaluating density-evenness of patterns printed on an article includes a circuit for calculating density distribution of the image data in each segment; a circuit for normalizing the density distribution with an area of effective image data in each segment; and a circuit for quantifying the density and evenness of the patterns.

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Kawasaki, Japan

Hiromichi Iwase