Research On Theory And Calibration Technologies Of Micro-scanning Infrared And Visible Dual-band Microscopic Imaging

Thermal microscope imaging can observe,record,and analyze the temperature change process of small targets.It has a broad application prospect in some nondestructive testing fields based on micro-thermal analysis.How to improve the performance of thermal microscope imaging systems and reduce their cost has always been a hot topic in the field of thermal microscope imaging.This paper studies the theory and calibration technology of micro-scanning infrared and visible dual-band microscopic imaging based on the uncooled optical micro-scanning thermal microscope imaging system.(1)Aiming at the problems of imperfect theoretical research of thermal microscope imaging and lack of theoretical basis for system design,the performance evaluation and optimization theory of thermal microscope imaging systems based on the temperature resolution model is studied.The models of the minimum resolvable temperature difference and minimum detectable temperature difference of thermal microscope imaging are established.The relationship between the microscopic mode and temperature resolution model in the telescopic mode is explored,and the system’s change of temperature resolution capability with magnification is analyzed.The theoretical models of different detectors are deduced,and the effects of background temperature and spatial frequency on the temperature resolution of the system are simulated and analyzed.Based on the model derivation and simulation analysis,The theoretical results which have guiding significance for the design and optimization of micro thermal imaging system are obtained.(2)Aiming at the problem of error superposition in the micro-scanning process caused by the lack of machining accuracy,based on the double coordinate system,microscanning principle,and image registration theory,the adaptive calibration technology of each point of the optical flat-panel micro-scanning system is studied.The issue’s calibration angle and rotation direction are calculated when it is located adjacent to the zero point and diagonally.An adaptive calibration strategy for each point in microscanning is determined based on the empirical threshold.The experimental results of simulation and system reconstruction show that the proposed calibration technique can reduce the error of the micro-scanning system and improve the spatial resolution of the thermal microscope imaging system.(3)Aiming at the problem that an uncooled thermal microscope imaging system is insensitive to texture changes and the imaging depth of field is small,the fusion technology of infrared and visible micro-images is studied by combining thermal microscope images with visible micro-images.A feature enhancement fusion method based on a guided filter is proposed.Firstly,a new local linear model is designed,which realizes the effective combination of infrared pixel intensity and visible light texture details;Secondly,the edge perception and contrast control factors are intended to enhance the contrast of texture details in adaptive weak active areas.Finally,the dual-scale infrared feature enhancement strategy is adopted to improve the infrared feature information in the fusion results.The experimental results show that the proposed method can combine the typical features of infrared and visible images,enhance the contrast of soft texture and effectively improve the visibility of microscopic images.(4)Aiming at the problem that the feature-based enhancement method proposed in this paper may introduce noise and can’t keep adequate information according to visual tasks,an infrared and visible image fusion algorithm is proposed based on the visual attention mechanism.Firstly,to highlight the target and suppress the background clutter in the saliency map,an optical attention system is designed to extract the salient visual features of the source image accurately.Secondly,a salient feature adaptive fusion strategy based on the correlation between image content and features is proposed,and a salient map is constructed based on salient visual features.Finally,the fusion strategy based on a saliency map combines infrared and visible images,and the texture details of weak active areas are moderately enhanced.The experimental results show that this method can effectively retain the tiny targets in microscopic images,with uniform brightness distribution and precise edge contour,and has achieved sound and visual effects.