Recognition of electrical symbols in document images using morphology and geometric analysis

A robust and efficient algorithm for recognition of electrical symbols in digitized documents is proposed. The algorithm is based on morphological operations and geometric analysis to recognize different classes of symbols. Its novelty lies in building and usage of three spaces, namely H-, V -, and C-spaces, which respectively contain the horizontal line segments, the vertical line segments, and the circuit symbols present in the concerned drawing. These three spaces are built by morphological operations, which, in turn, are searched and scanned in a scientific way during the geometric analysis in order to obtain the recognized symbols by verifying the structural combination of their constituent primitives. Exhaustive experimentation has been performed to test the performance of the algorithm. Some of the results are presented in this paper to demonstrate its robustness, efficiency, and versatility.