Research On Enhancement Method Of Infrared Image Based On Theodolite

Photoelectric theodolite is an optical measure device widely used in astronomy and aerospace measurement, its main function is to provide real-time image of flight targets, record flight trajectory, and provide support for decision-making of the command center. Images provided by Photoelectric theodolite generally comprise the visible and infrared images. Research work in this paper is undertaken based on infrared image taken from a certain Photoelectric theodolite. Due to the system design and hardware performance, the infrared image from this Photoelectric theodolite has low spatial resolution, strong noise, especially in the margin area where the noise is both fixed and strong. Such image quality affects the operation of the operator and the judgment of the decision-makers, so the image need to be processed.In this article, combing with the Photoelectric theodolite infrared image, three aspects of research work including image dynamic range compression, enhancement of the target brightness and image enhancement via pseudo-color display is undertaken, the infrared image enhancement algorithm is studied, and simulated using Matlab software.The main work in this article mainly is: analyzed the statistical properties of the infrared image grayscale and noise characteristics, and proposed a hybrid infrared image enhancement method aiming at the problem that applying the ordinary infrared image enhancement methods can hardly improve the quality of the infrared image.This method has three steps: firstly, based on histogram characteristics of the infrared image, apply the redundant dynamic range compression to the infrared image; secondly, implement a certain process to the strong noise in the image margin, to effectively get rid of this fix noise which can severely impact the visual effect; and finally use the hybrid filtering method to enhance the brightness of the target, improve the image contrast, and suppress the background noise. To further improve the viewing experience of people to the infrared image, two methods of pseudo- color infrared image transformation is applied that further improve the visual effect of the targets.The simulation results show that this method has better effect than the original image enhancement method used in the Photoelectric theodolite, and can meet the requirement of real-time processing.