METHOD OF NOISE-IMMUNE GRADIENT DETECTION OF CONTOURS OF OBJECTS ON DIGITAL IMAGES Russian patent published in 2009 - IPC G06K9/48 H04N1/409 

FIELD: information technology.

SUBSTANCE: present invention relates to digital processing of images and can be used in photographic, video, optical-location and optical-electronic engineering for identifying images from their contours on digital images. The method of noise-immune gradient detection of contours of objects on digital half-tone images is based on preliminary assessment of the location of impulse noise on the image, after which four auxiliary masks are formed, as well as four corresponding control vectors. Using vector data, coefficients of the corresponding four differently aligned Previtt masks are changed. After this the approximate value of the module of the image gradient is calculated using mask data, and contours of the objects on the image are obtained from its threshold conversion.

EFFECT: increased stability of gradient operators for contour detection to impulse noise, arising from many conditions for transferring and converting images.

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