Descirption Of Image Region And Applied Research

The vectorization of imageis is a difficult problem in image processing. imagevectorization has a great application in many fields, such as GIS system, CAD system,image compression and transmission. Image vectorization should solve two difficultproblems, the one is the image segmentation, get the boundary of the target in form ofdiscrete pixels; the other is using the line or ellipse arcs describe the pixels. Vector methodthat this paper is focused on is a key technology of image vectorization.First, this paper studies how to use the data point to adjust arbitrary b-spline curvesegment. On the analysis of the vector control vertices and nodes of b-spline curves, thepaper researches the influence of b-spline curves by modifing data points and insertingpoint The study found that modifing data points or inserting point, affect the part of thecontrol vertices, node, and the shape of the curve segment. The paper gives the specificimpact control vertices and nodes, the related curve segment, and the new control vertexcalculation expression. From the concrete experiment verified by inserting type value pointon the curve segment interval, the feasibility of the combination type value point on thecurve segment interval and modify the shape of curve type outside points both, can achievethe result of adjustment of arbitrary b-spline curve segment.Select the B-spline curve as the fitting curve to describe the boundary. Using thetracking algorithm to get the edge of image, Select the points of maximum curvature in thegroup as the dividing point, us the lattice method to obtain the minimum distance, comparesthe minimum distance with the error threshold. The results of comparing as the standard toinsert the data points, obtained the B-spline curve. Compared with the curve fittingboundary of general algorithms, the algorithms that the paper takes out has manyadvantages. first, insert the data points only affecting the local control vertex of B-splinecurve, so just calculates the affected control vertices instead of all the control points; second,Based on the properties of B-spline curve, calculate the minimum value by lattice methodjust from the corresponding interval insteading of the whole curve. This can reduce the timeand increase the speed of processing.