UFPA non-effective pixels distinguishing method

Abstract

A method for discriminating invalid pixels in a UFPA belongs to the technical field of infrared thermal imaging, and relates to a method for discriminating invalid pixels in an uncooled infrared focal plane array (UFPA) in an image preprocessing stage. According to the pixel response characteristics, the invention automatically searches out the optimal invalid pixel identification threshold by means of cyclic iteration, determines the distribution of the invalid pixel on the focal plane, and forms an invalid pixel position mapping table. Compared with the prior art, the present invention does not need to set the invalid pixel discrimination threshold based on experience; and in the process of loop iteration, as the number of invalid pixels increases, the iteration step is gradually shortened, and this variable length search makes the There is a faster convergence speed at the beginning of the iteration, and then the search step is gradually reduced to make the search more accurate when the data is close to the stable value, so as to ensure efficient and accurate judgment of invalid 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 discriminating invalid pixels in an uncooled infrared focal plane array (UFPA) in an image preprocessing stage. Background technique [0002] The uncooled infrared focal plane array overcomes the shortcomings of the usual 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 the fields of national defense, electric power, fire protection, petrochemical and medical treatment. 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, processes and other factors, the video output amplitude will ap...

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.