Mechanical drawing comparison method based on local connection feature matching

Abstract

The invention discloses a mechanical drawing comparison method based on local connection feature matching. The main idea of the method is as follows: firstly, obtaining a difference area of two mechanical drawings which are compared, finding out respective connected drawings in two original drawings corresponding to the difference area, and then separating graphs and characters in the connected drawings to obtain connected drawings without characters; secondly, refining the connected image into a single-pixel image, and extracting feature points in the image; detecting a connection relationship between the feature points; establishing a feature point descriptor matrix and a feature point distance function; classifying the feature points according to connected domains; and finally, matchingthe same type of feature points by using a feature point distance function, wherein the feature points which are not matched and the corresponding connecting line graphs are the modification areas ofthe mechanical graphs of different versions. The method provided by the invention has good matching and comparison effects on images without obvious gray and texture features, such as mechanical drawings, and has the characteristics of strong stability and high accuracy.

Description

technical field [0001] The invention relates to the field of mechanical drawing recognition, in particular to a method for comparing mechanical drawings based on local connection feature matching. Background technique [0002] In the process of mechanical drawing, designers use auxiliary design software such as AutoCAD and Solidworks on the computer to complete the design of mechanical drawings, and deliver the designed mechanical drawings to users in manufacturing, circulation, and use. These users often move away from paper drawings to electronic versions of mechanical drawings. Usually designers use mechanical drawings in vector format, while mechanical drawings in non-vector formats such as tif, pdf, png, etc. are usually released to users. Users can directly display, save, edit and modify these files on the computer. Designers often need to make multiple revisions and changes to the drawing content, resulting in multiple versions of mechanical drawings. In order to g...

AI Technical Summary

Problems solved by technology

[0004] When engineers and users compare the raster images of different versions of mechanical drawings, it is time-consuming and error-prone.

Images