Image processing method and apparatus

Abstract

For the purpose of conducting anisotropic diffusion filtering in a shorter time, an image processing method for conducting anisotropic diffusion filtering on a pixel value I i, j in a two-dimensional image, comprises: finding conduction coefficients C n , C s , C w , C e , C nw , C sw , C ne and C se in eight surrounding directions for each pixel based on a pixel value gradient ˆ‡I to produce a two-dimensional distribution image of the conduction coefficients; and finding pixel value first partial differentials ˆ‡ n I, ˆ‡ s I, ˆ‡ w I, ˆ‡ e I, ˆ‡ nw I, ˆ‡ sw I, ˆ‡ ne I and ˆ‡ se I in the eight surrounding directions for each pixel to calculate a pixel value in an output image according to: I i,j n +1 = I i,j n +»[[ C n �¢ ·ˆ‡ n I + C s �¢ ·ˆ‡ s I + C w �¢ ·ˆ‡ w I + C e �¢ ·ˆ‡ e I ] + 1 2 [ C nw �¢ ·ˆ‡ nw I + C sw �¢ ·ˆ‡ sw I + C ne �¢ ·ˆ‡ ne I + C nw �¢ ·ˆ‡ nw I ]] i,j n , (n: the number of times of repetition, »: a constant).

Description

technical field

[0001] The present invention relates to an image processing method and device, more specifically to a method and device for implementing anisotropic diffusion filtering on a two-dimensional image. Background technique

[0002] Filtering techniques capable of removing noise from a two-dimensional image without side effects such as edge degradation include anisotropic diffusion filtering.

[0003] The anisotropic diffusion filtering includes obtaining pixel differential values ​​with respect to the nearest surrounding pixels of each pixel, obtaining a conductance coefficient (conduction coefficient) of each pixel based on the pixel value gradient, and using these conductance coefficients and pixel differential values ​​according to a predetermined Calculate the formula to calculate the pixel value in the output image.

[0004] The calculation formula is of a space-proportional type in which the calculation result in one pass is used as an input for the next pa...

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