Segmentation of plate dot image based on image processing techniques

The accurate of printing plate dot size makes a significant impact on the reproduction of image gradient and color in the halftone image replication. Therefore, in order to eliminate the effect of noise, first of all we filter the acquisition of digital image, and then using threshold segmentation algorithm experiments on different dot image. In this paper two methods are proposed, and we named them average filtering seeking threshold method and median filtering seeking threshold method. Experimental results show that the average filtering seeking threshold method is more effective in high light and shadow areas, and in the mid-tone areas the average filtering seeking threshold method is more accurate.