在数字散斑干涉术中,通常由物体变形前后得到的两幅原始散斑场用相减方法来得到条纹图,并由相移后的多幅(三幅以上)条纹图来求取相位场。介绍了一种基于条纹等值线相关的条纹图生成新方法,并在此基础上提出了基于单幅干涉条纹图的相位场提取新方法和基于条纹等值线相关的单步相移新方法。实验结果表明,该方法具有良好的结果和发展前景。
In digital speckle pattern interferometry, tbe fringe pattern is usually derived by executing subtraction operation between two speckle patterns acquired before and after deformation of an object, and it is inherently full of speckle noise which makes the post-processing of the phase extraction difficult. A novel method to generate a speckle-noise free fringe pattern is proposed. With the new method, the correlation between two speckle patterns is performed only within contoured windows instead of rectangular windows and this contoured correlation results in a smooth, normalized fringe pattern without speckle noise so that the full phase field can be extracted from this single fringe pattern. Furthermore, this novel mothod is extended to the phase-shifting for DSPI after its improvement. The experiments on actual image show that the new methods have good results and application prospects.