Correction method for multiple error-diffusion half-tone

Abstract

The invention discloses a correction method for a multiple-error-diffusion half-tone, and the method is realized through the following steps: performing color separation to a color digital image through a color separation module, so as to obtain a single-channel gray level image; and then, acquiring a tone grade interval value, and acquiring a corresponding tone value through the tone grade interval value; performing multiple-error-diffusion treatment by adopting the multiple-error-diffusion algorithm and using a four-neighborhood error-diffusion kernel, so as to acquire a half-tone image; and finally, acquiring accurate false contouring zone margin through adopting the opening operation in the mathematical morphology, and correcting the corresponding tone value through adopting the marginal growth method, so as to eliminate the false contour in the image; and finally, acquiring a corrected image. The correction method disclosed by the invention can improve to a great extent or even completely eliminate the false contours in a conventional multiple-error-diffusion half-tone image, the algorithm is simple and easy to carry out, and the corrected image is more suitable for printing or printing to be output. The correction method disclosed by the invention can be internally built in an RIP to serve as a correction module for multiple-printing or printing out half-tone images.

Description

technical field [0001] The invention relates to the field of image hard copy reproduction, and more specifically relates to a method for correcting multilevel error diffusion halftone. Background technique [0002] In the process of image hard copy reproduction, the field of image hard copy has broken through the traditional binary output. But the existing multi-value output technology is not mature, for example, the multi-level dots or multi-level ink dots on the hardware are not ideal, or the multi-level halftone algorithm of the image also has its own defects. Among the common multilevel halftone algorithms, the multilevel error diffusion halftone method is widely accepted and recognized, but the halftone images generated by this method will have more obvious artificial traces, that is, false contours. The so-called pseudo-contour phenomenon refers to the appearance of contour traces that do not exist in the original image in some gentle transition areas of the image. Th...

AI Technical Summary

Problems solved by technology

[0005] In the method for carrying out multi-level halftone to the image existing in the prior art, adopt the multi-level error diffusion algorithm to cause the problem that there is obvious pseudo-contour phenomenon in the half-tone slowly changing area on the image after half-tone, the object of the present invention It provides a multi-level error diffusion halftone correction method, which uses mathematical morphology to extract the false contour edge, and then corrects the false contour by the method of edge growth, so as to achieve the purpose of reducing or eliminating the false contour

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