Improve The Signal Distinguish From Course Of Warn-noise Through Image Enhancement Technology

Digital image processing is a new area of computer application. It was developed with the development of the technology.Image strengthen is a important branch of the image processing in order to improve the sight effect, and make the image in focus, and be easier to be analysed. "To improve" is to improve the peculiarity of the whole image or part of it in some situation. It's purpose is not to save all the information, but to stand out the information be interested, and restrain the information useless.In the image of the guard history of some sonar, the grayscale is very small. It can't be determined when the signal is very weak. In this article, the theory and the characteristic of the image is construed. The grayscale transform and the wavelet transform is used to strengthen the guard history image.The strengthen by grayscale transform is used in the space field. It's mature and simple. But the wavelet transform is still being researched in the area of the image processing. The wavelet transform include the operation of decompose and compose, so the amount of data is very big, it costs more time to operate, and a faster hardware is required. The arithmetic theory and realization of grayscale transform is discussed in this article, and the emphases is the wavelet transform. The character of the image can be stand out is the main characteristic of the wavelet transform. In this article, we firstly review the history that Wavelet developed, after that, we discuss filter algorithm including FFT algorithm, Fast-running algorithm and Distributed algorithm. The particular arithmetic and the result of the experiment is given based on the image of the guard history and the condition of the hardware and the software.Finally, a compare is taken between the two methods in the opinion of the worthiness of application and the difficulty of realization.