It is well known that optical tomography can accurately and quantitatively reconstruct the refractive index field of a transparent medium and display the three dimensional image of other physical quantities relevant t...It is well known that optical tomography can accurately and quantitatively reconstruct the refractive index field of a transparent medium and display the three dimensional image of other physical quantities relevant to temperature or density. In this paper, a new multidirectional holographic interferometric system is built, and two kinds of image reconstruction algorithms are introduced and an automatic image processing system of interferogram is designed. A three dimentsional asymmetric gas flow field above a combustor is expertmentally investigated with holographic interferometry. The reconstructed temperatures are similar to those measured with a thermocouple.展开更多
The gray level values of target pixels of infrared images processed by the SUSAN noise filtering algorithm and the background filtering algorithm are calculated,assuming that the target distance is given in image acqu...The gray level values of target pixels of infrared images processed by the SUSAN noise filtering algorithm and the background filtering algorithm are calculated,assuming that the target distance is given in image acquisition.The equivalent blackbody temperature is obtained by the temperature calibration model that represents the quantitative relation,at a certain integration time,between the gray level value and the equivalent blackbody temperature.The temperature calibration model has been acquired by the curve fitting with the experimental data of blackbody temperature calibration using Origin 6.0.Then the target radiance can be determined by the radiant flux equivalence model built on condition that the target radiant flux received by the infrared detector is equivalent to that of the blackbody placed in front of the infrared detector at a close distance.This measuring method is based on the temperature calibration parameters and real image information,so it can avoid subjectivity of the traditional theory modeling methods.展开更多
We start from a realistic half space then use to develop a mathematical asymptotic model for thermal imaging, which we analysis well suited for the design of reconstruction algorithms. We seek to reconstruct thermal a...We start from a realistic half space then use to develop a mathematical asymptotic model for thermal imaging, which we analysis well suited for the design of reconstruction algorithms. We seek to reconstruct thermal anomalies only through their rough features. With this way our proposed algorithms are stable against measurement noise and geometry perturbations. Based on rigorous asymptotic estimates, we first obtain an approximation for the temperature profile which we then use to design noniterative detection algorithms. We show on numerical simulations evidence that they are accurate and robust. Moreover, we provide a mathematical model for ultrasonic temperature imaging, which is an important technique in cancerous tissue ablation therapy.展开更多
文摘It is well known that optical tomography can accurately and quantitatively reconstruct the refractive index field of a transparent medium and display the three dimensional image of other physical quantities relevant to temperature or density. In this paper, a new multidirectional holographic interferometric system is built, and two kinds of image reconstruction algorithms are introduced and an automatic image processing system of interferogram is designed. A three dimentsional asymmetric gas flow field above a combustor is expertmentally investigated with holographic interferometry. The reconstructed temperatures are similar to those measured with a thermocouple.
基金Supported by Innovation Project of Chinese Academy of Sciences(Grant No.C04708Z)
文摘The gray level values of target pixels of infrared images processed by the SUSAN noise filtering algorithm and the background filtering algorithm are calculated,assuming that the target distance is given in image acquisition.The equivalent blackbody temperature is obtained by the temperature calibration model that represents the quantitative relation,at a certain integration time,between the gray level value and the equivalent blackbody temperature.The temperature calibration model has been acquired by the curve fitting with the experimental data of blackbody temperature calibration using Origin 6.0.Then the target radiance can be determined by the radiant flux equivalence model built on condition that the target radiant flux received by the infrared detector is equivalent to that of the blackbody placed in front of the infrared detector at a close distance.This measuring method is based on the temperature calibration parameters and real image information,so it can avoid subjectivity of the traditional theory modeling methods.
基金supported by the ANR project EchoScan(AN-06-Blan-0089)the NSF grant DMS 0707421.
文摘We start from a realistic half space then use to develop a mathematical asymptotic model for thermal imaging, which we analysis well suited for the design of reconstruction algorithms. We seek to reconstruct thermal anomalies only through their rough features. With this way our proposed algorithms are stable against measurement noise and geometry perturbations. Based on rigorous asymptotic estimates, we first obtain an approximation for the temperature profile which we then use to design noniterative detection algorithms. We show on numerical simulations evidence that they are accurate and robust. Moreover, we provide a mathematical model for ultrasonic temperature imaging, which is an important technique in cancerous tissue ablation therapy.
