Method for discriminating non-effective pixel in UFPA

Abstract

A method of judging a non-effective pixel in UFPA belongs to the infrared thermal imaging technical field, and relates to a method of judging a non-effective pixel in an uncooled infrared focal plane array (UFPA) in the preprocessing stage of an image. An optimum non-effective pixel identification threshold value is automatically searched out according to the pixel response characteristic and by the method of loop iteration, and the distribution of the non-effective pixels on a focal plane is determined to form a position mapping table of non-effective pixels. Compared with the prior art, the invention does not need to set discriminant threshold of non-effective pixels according to the experience. In the process of loop iteration, with the increase of the non-effective pixels, the iteration step length is shortened increasingly. The variable length search enables the initial iteration stage to have higher velocity of convergence, and the step length is shortened increasingly so that the search is more accurate, thereby ensuring high efficiency, and accurately judging the non-effective pixels.

Description

Technical field [0001] The invention belongs to the technical field of infrared thermal imaging, and relates to an infrared focal plane array device, in particular to a method for judging invalid pixels in an uncooled infrared focal plane array (UFPA) in the image preprocessing stage. Background technique [0002] The uncooled infrared focal plane array overcomes the shortcomings of ordinary infrared technology that requires cooling. It is easy to use, low power consumption, small in size, and light in weight. It has been widely used in national defense, electric power, fire protection, petrochemical and medical fields. It is playing an important role in the development of the world economy. On the other hand, people's requirements for image quality are getting higher and higher. However, due to the inhomogeneity of the semiconductor material used to make the device, mask errors, defects, process and other factors, the video output amplitude will appear uneven, and the extreme ca...

AI Technical Summary

Problems solved by technology

[0004] 1) In the UFPA manufacturing process, the unevenness of the photosensitive material and its doping concentration will cause the fluctuation of the photoelectric conversion characteristic curve of each detection unit and the change of the dark current. When the inconsistency is too large, the An invalid cell is formed;

[0005] 2), 1 / f noise will also deteriorate the performance of the detection unit and form invalid pixels;

[0006] 3) The influence of signal charge transmission and readout. In UFPA devices using shift readout, channel obstacles can attenuate the relevant pixel signals to form invalid pixels;

[0007] 4) Random changes in the temperature where the UFPA device works will affect the performance of the pixels. Under a certain ambient temperature, such as too high or too low an operating temperature, some pixels will deteriorate in performance, lose their detection capabilities, and become invalid cell

This detection method is to identify invalid pixels by analyzing a large amount of data and extracting data features, so the collection and processing of massive data is required, and the workload is heavy and cumbersome.