Research On Ghost Imaging Optimization Method Based On Speckle Field Transformation

Ghost imaging,also known as correlated imaging,is an indirect reconstructed technology to reconstruct the information of the target to be measured by using the principle of spatial intensity correlation.Compared with the general photoelectric imaging method,this non-local correlation imaging mode can break through the traditional image of a light energy distribution on array detector pixel intensity limit and effective extension of imaging range,thus in X-ray medical image,the city security monitoring and other aspects has great practical meaning,is an prerequisites of target detection and recognition.However,the actual environmental imaging process not only requires a large number of measurement data,but also has the limitations of inferior signal-to-noise ratio,small visibility,sluggish reconstruction effectiveness and other reconstruct ghost,which seriously restricts the detection effect of the system in the fields of smart medical assistance,smart surveillance and so on.Therefore,how to optimize ghost imaging method to make better the quality of target recovery is the key to avoid the bottleneck phenomenon mentioned above.For this reason,from the perspective of optimization the reconstruction effect of correlation imaging and reducing the measurement data,this paper constructs three feasible correlation imaging reconstruction image quality optimization models,so that the detection result of ghost imaging can meet the Real environment requirements demand.The key research works of this text are as below:(1)The relationship between orthogonalization of speckle field and ghost imaging is studied.First,the formula is used to derive and verify that the orthogonal speckle field can achieve complete reconstruction of the target under full sampling;then,by analyzing the imaging mechanism of sinusoidal ghost imaging,it is confirmed that the sine speckle type and the cosine speckle type are respectively used for imaging.Due to the redundancy between the speckle fields,the orthogonalized sinusoidal speckle field is constructed.Finally,the specific process and details of ghost imaging using orthogonalized sinusoidal speckle are improved,and the performance of the proposed mode in cutting down the time of sampling data and improving the imaging quality is verified through experiments.(2)The relationship between the combination of speckle patterns and correlated imaging is studied.First,the average distance matrix between the speckle patterns is calculated by introducing the Euclidean distance,and it is clear that the combination of the speckle patterns can increase the difference between the speckle fields.Then the combination modulation strategy of speckle pattern and bucket detector value is constructed,and the selection range of the best combination length is determined.Finally,the specific process and details of ghost imaging using combinatorial modulation are improved,and the performance and universality of the proposed mode in cutting down the redundancy and data volume between the data to be associated are verified by experiments.(3)The relation between speckle field frequency domain transformation and ghost imaging is studied.Firstly,the necessity of spectral speckle processing in frequency domain is analyzed by introducing the theory of high and low frequency result.Secondly,a high-low pass digital rejector is structured,and the optimal threshold is selected by experiment.Then the spatial pattern is decomposed by frequency transform rejector to get the high/low frequency speckle pattern,and the high/low frequency reconstruction result of the object to be detected is reconstructed by associating the gather data with the above speckle field.Then the non-subsampled shearwave transform image fusion way is combined into correlated imaging and a fusion correlated imaging algorithm based on frequency domain decomposition was advanced.Finally,the proposed process and details are enhanced,and the capability of the advanced model in making batter the restore result of unknown targets is simulated through test.