The Study About Measuring Object Deformation By Using Double-exposure With Gray-level

In digital holography,the holographic information is directly recorded on a charge-coupled device(CCD or CMOS)camera and saved in the computer.The optical reconstruction is also replaced by a computer numerical reconstruction.With the rapid development of computer technology, digital image processing technology and photoelectric instrument,digital holography has recently became feasible and have been used in many fields.In contrast with traditional holography,digital holography have the advantage of anti-interference and real-time(such as deformation,the change of temperature or displacement etc). With digital image processing technology, the display effect and processing speed of hologram could be improved.The purpose of this paper is to use double-exposure with gray-level in order to find out a new quick and simple method for measuring object deformation.Based on theoretic analysis and optical experiment,this paper focus on the following aspects mostly:l.The principle of digital double-exposure to measure object deformation is introduced,then a detection program is developed with Matlab.2.The measuring optical path is designed,and taken some interference pictures.3. With digital image processing technology, the interference fringe number is calculated by using double-exposure with gray-level,so the deformation value could be obtained.The result of experiment is satisfying,and prove that the method is effective means to measure object deformation,without using unwrap the phase.4.Through optical experiment, scope of application and relative error about this method is found out under present condition,and the method of improvement the accuracy of measurement is talked about as well.