Feature-Based Symbol Recognition for Construction Engineering Drawings

Symbol Recognition in machine reading of engineering drawings plays the key role of integrating the processes of architecture design, drawing verification, budget making and construction planning. A method to extract visual features and organize feature templates for recognizing architecture engineering symbols is presented. The recognition process is based on verifying the necessary and sufficient conditions of each kind of symbol according to a predefined order of precedence. Besides these, several useful techniques are used to accelerate recognition.