Abstract
We developed an input method of plant diagrams, which can convert paper-based diagrams efficiently to computer database. A diagram to be input contains so many elements, i. e. symbols, connection lines and characters, which are often touching each other, so that the conventional automatic input techniques were not adequate. Our method of recognition and verification together reduced the time needed to input a diagram to be 30%, compared to manual input using a CAD input terminal.
In recognizing such a diagram, we first detect elements with loops or black regions, which are apparently separable. And upon these features, the system parallelly detects and judges symbols. And the symbol recognition results are feedbacked to detect other elements, namely lines and characters. In this manner, we succeed to cope with elements, which are touching each other.
