The Design Of Infrared Image Acquisition System In Inland Waterway Based On FPGA

With the continuous development of river shipping industry, maritime accidents are also likely to increase, the ship collision accidents are more likely to happen particularly in low-visibility conditions. Thus, it is an important problem to take effective measures to prevent ship collision. The core problem to avoid the collision is how to obtain the location information of other ships accurately. Infrared imaging equipment is widely used in image acquisition system for its strong anti-interference, climate adaptability, continuous passive detection day and night and other advantages of. The main task of this subject is to design a FPGA-based infrared image acquisition system of river, through installing the thermal imager in the ship, collecting infrared video data, providing forward looking image information for the operating vessel personnel, at the same time, sending the preprocessed data to follow-up image processing for ship object detection unit, in order to supplement the crew to make decisions and operate correctly, decreasing water accidents, safeguarding lives and properties and finally insure inland navigation safety.This paper first analyzes the current main video image acquisition system. Through the comparison of the core processor chips, the infrared video image acquisition system is designed, which uses FPGA as the core processor. Philips SAA7113H is used to decode the video in the video decoding module, SDRAM is the input and output data buffer, RAM in FPGA is also employed in production-line system for median filtering and the sky-water line detection. The data after the preprocessing is send to the DSP for subsequent image processing. Finally VGA is adopted to display infrared images.This paper studies the hardware implementation of image acquisition system and function realization on FPGA. At the same time, analyzes the characteristics of infrared images, and chooses median filtering for image enhancement, and programming for fast median filtering algorithm. Ships in the Inland-water infrared image always near the sky-water line. In this paper, through a comparative analysis of sky-water line detection algorithm, a sky-water line detection algorithm based on linear fitting is proposed. Detecting the sky-water line and getting the region of Interest(ROI), not only improve the follow-up processing speed, but also avoid most of the background interference, improve accuracy of target detection algorithms.