Automated identification of components in raster piping and instrumentation diagram with minimal pre-processing

This paper proposes a novel framework for automated recognition of components in a Piping and Instrumentation Diagram (P&ID) of raster form. Contour is used as the main clue for visual recognition through the use of Local Binary Pattern (LBP) as descriptor and concept of Spatial Pyramid Matching (SPM). Comparison of two image patches is done by calculating the l1 distance between two corresponding LBP based descriptors. Firstly, the framework requires at least one example image per type of component to be recognised, the corresponding LBP and SPM based descriptor is determined and stored. Linear sliding window approach is used to detect a small set of top candidates from a pool of all sub-images in original image. Verification against the entire library of symbols is performed on each candidate selected from previous stage, using concept of nearest neighbour based classification. The method has demonstrated state of the art performance in a new challenging dataset created with advices from a group of experienced engineers in marine and offshore industry.