Optimizing image format piping and instrumentation diagram recognition: Integrating symbol and text recognition with a single backbone architecture

Recent studies propose deep learning-based methods to recognize symbols and text in Piping and Instrumentation Diagrams (P&ID). However, existing approaches use complex processes with separate models for symbol detection, text detection, and text recognition. We propose an integrated model combining symbol-text detection and text recognition modules using a text spotting method. Our model extracts text region features encoded with local character information, enabling a lightweight text recognition module that reduces processing time. The integrated approach allows end-to-end learning between modules, facilitating semantic information transmission and improving overall performance compared to multi-model architecture. When tested on industrial P&ID images, our model achieved high performance with an IoU threshold of 0.5: maximum precision of 0.9763/0.9527, recall of 0.9521/0.9075, and F1 score of 0.9640/0.9295 for symbol-text detection/text recognition.