A real-time finite line detection system based on FPGA

Image processing and analysis are active research topics. An intelligent vehicle and a service robot require these techniques. In particular, there is a big demand for line detection because it has a wide range of applications. The line features in an image are used for object identification, robot navigation, and intelligent vehicle control. To detect the lines, a Hough transform is generally used. The Hough transform has good detection results and it is robust to noise, but it takes a long time to execute and it requires a great deal of memory to store the parameter space. This paper proposes a dedicated line detection hardware system. To increase the processing speed, it has a parallel Hough transform unit, and it partitions the parameter space to decrease the memory requirements. It can detect not only the line parameters, but also the exact start and end points of each line, and it sorts these lines by length. It can display the detected line on a monitor via the DVI interface. This system is designed with VHDL and implemented on an XC4VLX200 FPGA. The device usage is about 15% and the maximum clock frequency is 67 MHz. It can detect up to 256 lines in one image frame and it can process up to 149 frames per second. The simulation and real experimental results are given to verify the system performance.