A non-uniformity correction method for a maskless infrared thermal imager

Abstract

The invention discloses a non-uniformity correction method of a non-barrier infrared thermal imaging system. The method comprises the steps of: dividing a substrate temperature into M intervals according to a substrate temperature range, shooting black bodies of different temperatures in each temperature interval, dividing original output of a detector into N intervals, calibrating M*N frames of images, and storing the images; then, according to the substrate temperature, reading the calibrated M frames of images above and below the substrate temperature by the detector; and subsequently, according to a response value of each pixel point, determining corresponding values of two temperature curves above and below the substrate temperature, carrying out weighted calculation based on the substrate temperature, and obtaining a final output value. According to the invention, barriers are successfully removed in interval division of the substrate temperature in the calibration process, the non-uniformity caused by output non-linearity of the detector is also considered, and interval division is also carried out the original output of the detector, so that secondary calibration is not needed after all images are calibrated, a once for all effect is achieved, and the influences of non-uniformity caused by the non-linearity of the infrared detector are also solved.

Description

technical field [0001] The invention belongs to the field of video image enhancement, and in particular relates to a method for correcting non-uniformity of an infrared thermal imager without a shield. Background technique [0002] In the early 18th century, infrared light beyond the visible spectrum was discovered. After more than two hundred years of development and research, the application of infrared spectroscopy has made great progress. Infrared imaging systems developed slowly from the crude single-pixel detection equipment in the early days to the more advanced liquid nitrogen or complex cooling microbolometer systems in the late 1980s. At that time, the systems were expensive and not portable, making The application of the movement has remained in important fields such as national defense and aerospace for many years. [0003] With the development of technology, the performance of detectors, movement and software system has been improved to a certain extent, and th...

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Problems solved by technology

In this way, the ambient temperature can also be taken into account, that is, when the substrate temperature drifts, the ambient temperature also drifts. At this time, the background needs to be re-calibrated, so the shutterless technology completes the work of correcting the background at any time and overcomes the temperature drift. However, this method does not consider the influence of different real targets on the output response of the infrared detector, and still does not solve the problem caused by the nonlinearity of the infrared detector. It can only be regarded as a one-point calibration algorithm. When the temperature difference is large, the non-uniformity caused by this nonlinearity becomes more obvious

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