Infrared Camera Auto-focus And Image Acquisition Technology

Auto focusing technology is an important technology to ensure the definition of the image in photographic acquisition equipment, it was applied in camera equipment at the earliest. Both domestic and foreign have made extensive research on auto focusing technology. From the ranging method,phase method and the contrast method in the early time to the focusing methods based on the digital image processing, auto focus technology is more and more digital and intelligent.In recent years, infrared thermal imaging technology has been developed rapidly and become an important subject of night vision technology. Our laboratory has been engaged in the research and development of infrared thermal imaging systems. In the infrared thermal imaging system, because of the complicated operation flow,strong subjectivity,strict requirement to the operator and producing visual fatigue in manual focusing, so the focused image may not stability and clear. Manual focusing costs too much time, so it can't adapt the requirement of modern imaging system automation. For this reason, realizing the auto focusing of the infrared thermal imaging system becomes critical, it is related to the imaging quality of the infrared thermal imaging system directly.This paper is committed to the auto focusing and image acquisition function, in order to obtain the clearest image from the infrared imaging senor in the shortest time. This paper introduces the basic theory, current situation and development of the auto focusing and image acquisition; analyzes several common image contrast evaluation algorithms; raises image contrast evaluation algorithm based on gray segmentation; researches the most important technology in auto focusing and then designs the focusing window selection method and the motor search strategy. which adapts our system; finishes the solution of auto focusing and image acquisition which centres on FPGA; analyzes the experiment results at last.The image contrast evaluation algorithm based on gray segmentation raised in this paper has advantage on sensitivity and instantaneity, the algorithm has been realized on the auto focusing system hardware platform of the infrared imaging senor and we have received satisfactory results.