Design And Implementation Of Image Trapping System Based On Edge Tracking Detection

In the printing process,there are two factors that result in white leakage.One factor is that theposition of multiple originally adjacent color lumps is not accurate or limited accuracy calculationresults in the white space at the junction of colors.The other is that after transmission of tension,thermal expansion and contraction of external force such as interference,white leakage appears in the paper.It is difficult to avoid white leakage phenomenon in printing process.And it easily yields the variant of image contour and poor visual experience of printed products,which will seriously affect products quality.A trapping scheme(repair white leakage)based on edge tracking detection and two key improved algorithms are proposed in this paper.The two improved algorithms are image edge detection algorithm based on eight direction chain code and sweep line boundary flag filling algorithm.Compared with the traditional trapping scheme,our scheme improves the accuracy of white leakage judgment,processing efficiency and the color imaging effect of trapping.Moreover,on the basis of the scheme,a trapping system based on edge tracking detection was designed and developed.This system implements functionalities for white leakage detection,filling white leakage,image smoothing,etc.In particular,our main work is summarized as follows:(1)Design and implement a module for white leakage detection.This module is mainly responsible for preprocessing basic functionalities,including image input,deciding whether the image is required to be trapped or not and saving white leakage information with our image edge detection algorithm.Our algorithm uses eight direction chain code to define edge coordinates and orientation coordinates,which improves the accuracy of the white leakage judgment and the efficiency of extracting an overall outline.(2)Design and implement a module for color scheme.This module formulates pixel values of leakage area by matching white leakage information and edge information.It provides color support for region filling module,including the calculation of internal and external edge color,the calculation of filling in gradient color and color component value calculation.(3)Design and implement a module for region filling.This module is mainly responsible for pixel compensation in the leakage area,including determination of filling edges and selection of filled pixels.Moreover,in this module a boundary flag filling algorithm is proposed to draw the entire white leakage area.The filling algorithm uses the method of horizontal or vertical scanning line to fill pixel intervals,avoiding the problem that original seed filling algorithm requires a time consuming recursive process.It also saves the storage space,thereby enhancing the filling efficiency.(4)Design and implement a module for post processing.The module is mainly responsible for the post processing after the completion of trapping,which includes Gaussian filtering in white leakage area,reducing color step degree of edge pixel and noise interference,as well as outputting or saving the processed image.Finally,the feasibility of our proposed scheme is verified and tested.Results show that it accurately extracts the contour features of white leakage area.In addition,it improves the reliability of white leakage judgment,the efficiency of white leakage filling and the accuracy of white leakage detection.It solves the low accuracy of white leakage edge area filling and poor color imaging effect problems in the traditional color trapping,and then improves the quantity of printing products significantly.