FIELD: information technology.
SUBSTANCE: invention relates to digital image processing. Disclosed is method for noiseless gradient selecting object contours on digital halftone images. Method includes preliminary operation of position estimation of noise on image, after which for each image element four opposing Previtt masks are formed, which values of coefficients are varied depending on availability and position of interference, and in presence of interference of simultaneously at three elements of any of hermetically sealed half masks of differently-directed masks, half mask size is increased by number of enclosing elements intact by interference. To weight coefficients of mask new elements values are assigned, which sum is equal to sum of values of modulus of second half mask. Then, using data of masks approximate modulus gradient image is calculated, and by its threshold conversion is obtained outlines of objects on image.
EFFECT: high sensitivity of gradient method of isolation of outlines to useful luminance image drops in conditions of pulse interferences.
1 cl, 13 dwg
