Making Imperfect Line Drawing Into Perfect Through Adding And Deleting Lines Using Labels

This master thesis is the project supported by Natural Science Foundation of Shaanxi Province (2002E224), Jiangxi Province (No.0311018), and Open Foundation of Research Center of Measuring Technologies and Control Engineering of Jiangxi Province (No.2003-013) .One goal of computer vision research is to give computers humanlike visual capabilities so that machines can sense the environment in their field of view, understand what is being sensed, and take appropriate actions as programmed.Recovering the three-dimensional scenes from a projected image or a line drawing is an important problem in computational vision. When a three-dimensional scene is projected to a two-dimensional image, a lot of three-dimensional information was lost, and the goal of the three-dimensional scenes restoration is to recover the lost information.The labels of a line drawing as an efficient method is take part in recovering the three-dimensional scene from the line drawing. Many impossible configurations can be excluded by consistent labeling, using the information of lines and junctions in the line drawing to forecast simply, so it can reduce workload in quantitative analysis.Many scholars have done a lot of works in study the theories and methods in labeling a line drawing, and proposed many effectual methods. But in fact, the lines are not linked in the line drawing we extracted from the projected image in many cases, thus the labeling could not be progressed farther, and be not interpreted and recognized objects the projected image denoted.In this thesis, we mainly study the method for deleting the false lines and adding the missing lines in an imperfect line drawing, and make the imperfect line drawing into a perfect. Using the existed theories and methods of labeling on a planar object, all possible configurations of imperfect line drawing have been exhaustively studied, and it is found that imperfect line drawings are closely related to junction form. In a perfect line drawing, there are has just three lines belonged to every junction. But in an imperfect line drawing, there must be junctions which connect line numbers be not equal to three, that is more or less. An efficient method for completing the imperfectline drawing through adding the missing lines and deleting the false ones is proposed. And for the sake of simple operation in computer, several operation modules and the flow are proposed. A computer implements operations for adding and deleting lines in an imperfect line drawing automatically.