In order to solve the problem of the existing single waveband thermal imaging system can’t get precise temperature of object with emissivity unknown, an optical system of beam splitting lens and filter were used to established a colorimetric temperature measurement system based on infrared thermal imaging system. Completed the compensation for non-effective pixel, enhancement of contrast, calibration of nonhomogeneity and coherence for infrared thermal imaging system according to the application requirement, then acquired the calibration data with blackbody as radiation source at 200°~500° and fit it. A temperature measurement test performed at last, compared with the result acquired by thermocouple and single waveband thermal imaging system, it was shown that the colorimetric pyrometry system achieve the attractive precision after calibration and applied to measure the temperature of the object with emissivity unknown.
For imaging equipments, exposure is one of the crucial factors for evaluating the quality of imaging. The correct method of exposure is the key to obtain high-quality image. Traditional calculation of exposure is slow in adaptation under extreme environment. In addition, the object of imaging under extreme light usually cannot achieve suitable gray level. To obtain accurate and effective control of automatic exposure under back light and front light environment, this article divides shoot scenes into different regions, applying the method of fuzzy logic to give each region a different weight number, and finally allowing it to correctly carry out automatic exposure. This method can manage imaging under special light conditions without being affected by the position of the main object. Experiments show that this method can effectively control automatic exposure under all kinds of environments.
This paper describe a research theoretically of the conversion result to the surface temperature based on long wave infrared detector, proposed a temperature measurement, then validate it by experiments. First, it introduces the constitution and measurement principle of the medical infrared thermal imager. Then, the conversion drift characteristic of infrared detect is described, the experimental data under variable environment is analyzed, and a temperature measurement and a drift compensation formula is proposed. Finally, some experiment with black body was accomplished. The results show the temperature error is under 0.3°C, confirm the validity of the measurement.