Study On The Electronic Image Stabilization Technology Of The Image Acquisition System In Ocean Buoys

With the development of video image processing technology, image ability enhancement, especially image information with intuitive, rich and convenient for real-time transmission and storage, make it become the primary means for intelligence of ocean buoy monitoring system in future. The research of PTZ image stabilization control system in Ocean buoy not only provide convenience for Marine data detection and scientific research, but also provide a visual basis for the relevant department of maritime surveillance to investigate and punish violations maritime rights and interests, damage to the Marine environment and resources, as well as to the emergency monitoring and investigation of major maritime events. However, in real monitoring environment, the image information obtained was unstable or fuzzy, which limited the effective use of image information due to the impact of attitude changes, ocean currents, wind, waves and other factors. In order to reduce or eliminate the influence, this topic designed a PTZ image stabilization control system based on ARM11.With the rapid development of precision machinery and microelectronics technology, inertial elements has been greatly developed, micro-mechanical gyroscopes has smaller volume, lower power, consumption and cost and better resistance to impact than optics and flexure gyroscope. Microprocessor based on ARM architecture is widely used for its high performance and low power consumption. Therefore, the PTZ image stabilization control system designed not only was small volume, low cost and fast response, but also could be solid installed.Gyroscope has high precision for short periods of time, but it isn’t conducive to the long-term operation. As time goes, the integration error is larger because of temperature drift, which affects the precision of attitude algorithm. The accelerometer is of long-term stability in attitude measurement, but it’s limited by carrier motion. The magnetometer has poor dynamic performance by the impact of buoy environment. In order to obtain high accuracy attitude angle and long-term stability, the thesis adopted the high order kalman filtering algorithm to optimize the output data of sensors. To reduce the amount of computation and computational complexity, the thesis utilized the quaternion algorithm instead of trigonometric functions to calculate the attitude angle of PTZ camera motion.Testing the PTZ image stabilization control system, the PTZ camera would complete reverse deflection with level 280 °/s speed, vertical speed 100 °/s, the longest feedback adjustment time was 0.38 s. Through the Matlab simulation in static case, the experimental results showed that the algorithm reached the preliminary stability with the accuracy ±0.1 degrees of pitching angle and ±0.2 degrees of azimuth angle.In systematic research of the key technology of electronic image stabilization(EIS) and its theoretical analysis, and focused on motion estimation and motion compensation for further research. Comparing the advantages and disadvantages of several motion estimation algorithms, the thesis selected block matching and the gray projection algorithm ultimately. By comparing the PSNR value of video sequence before and after the compensation to assess the quality of the algorithm, frame rate and search points was used to assess real-time performance of the algorithm.Combined with the movement of ocean buoys has rules to follow, the thesis improved the initial search point of search strategy in block matching algorithm. Using AR model based on time series to predict the vectors of horizontal component and vertical component of the global motion vector respectively. The predicted vector as the search starting point could reduce the search time; moreover, through the algorithm processing for shooting video, the experimental results showed that it had good stabilization effect.