Research And Application Of The Image Processing Technology For Weather Fax Map

Clear, accurate weather fax map can provide accurate meteorological and hydrological information,which has far-reaching significance for the safety of warship navigation.Embedded image processing technology in weather fax Figure receiving system will play an important role in the field of meteorology fax. It can effectively overcome the difficulties of traditional weather fax map difficult to deal with, and broaden the field of use for weather fax map, increasing the depth and breadth of meteorological information in the field of application of the voyage.Based on the further study of weather facsimile chart receiving and processing technology, in view of the weather facsimile chart receiving noise problems, improve the weather facsimile chart receiving hardware system, and apply the weather facsimile image digital processing algorithms to the system.Through the actual receiving experiment, verify the feasibility of the improved image processing algorithm.This paper set up the fax receiving system hardware test platform, completed the receiving application software design. RF front-end of hardware paltform adopt a two-stage superheterodyne manner, and the module achieves filtering , amplification and mixing for the RF signal; digital signal processing module using a manner of digital down converter for demodulating IF signal.Weather facsimile image processing algorithms mainly complete the image noise reduction,compression and recognition processing. Because the weather fax map vulnerable to a variety of outside interference when it spread in space, and will occur fading phenomenon by the way of short-wave, resulting in receiving a poor weather fax map.Through statistical experiment of receiving data,to improve the traditional de-noising algorithm,compare various algorithms of the noise reduction effect, according to the actual situation of noise, design a suitable noise reduction algorithm for weather facsimile chart.Compression coding not only can guaranteed the quality of image transmission, but also can effectively improve the speed of image transmission.This paper analyzes the traditional characteristics of run-length coding and Huffman coding, using the run-length coding and Huffman encoding encoding to compression coding of weather facsimile chart, improved the weather facsimile image compression ratio, which is advantageous to the image of the high speed transmission.In order to achieve the further application of fax images, it is necessary to recognize and extract longitude, latitude, coastline and isotherm for fax figure. Based on analyzing some literature about weather facsimile chart, this paper simplified the algorithm realization process, improve the real-time performance of the algorithm. The improved image recognition algorithm can satisfy the real-time requirements of the system.Currently, weather fax chart processing technology is gradually deeper and mature,which will provide a richer scientific basis for decision making mariners weather, so as to provide a strong security for marine navigation. With the development of computer network technology receiver, digital signal processing and image processing technology, the technologie of displaying and processing weather fax map will change dramatically, I believe that the role of meteorological information in the warship voyage will be increasing.