Real-time line detection in omnidirectional images with an FPGA for monitoring and reporting applications in production processes

In this paper we introduce an approach to FPGA-based line detection in omnidirectional images, taken by an upward-oriented camera. This approach can be used as a basic technology for indoor positioning and therefore for many applications which need to estimate the user positions inside electromagnetically shielded buildings or ship hulls. The detected lines can be compared with lines from the edge model which is derived from the existing CAD model of the surrounding room. The paper starts with a short summary of related work in the domain of indoor positioning, the mathematics behind line detection by the Hough Transformation (HT) as well as an explanation of the Omnidirectional Hough Transform (OHT). In the second part the context of the main contribution is described including the hardware setup and application requirements. After that a novel approach to line detection using the OHT on FPGA is presented and the OHT Module is introduced. Then we show the results and make a comparison between our FPGA implementation and the implementation on a desktop computer. The paper ends up with a conclusion and an outlook to future works.