Calibration and Target Signal-to-Noise Ratio Enhancement Method of Infrared Camera Array Based on Refocus

Abstract

The accuracy of infrared (IR) camera calibration directly affects the quality of IR imaging results. Many imaging devices have been utilized in infrared dim and small target detection, which is a major research direction in infrared field. Comparing with single-lens cameras, IR camera array can improve the detection capability by adding more imaging units, and is expected to break the limitations of traditional single-lens imaging system in cost, volume and performance. The calibration methods for camera array nowadays are generally applied in visible spectrum instead of IR band. In this paper, we proposed a calibration method based on refocus for IR camera array. Furthermore, the target signal-to-noise ratio enhancement method become effective after calibration of IR camera array. As the camera parameters obtained can be used to correct image distortion and improve the quality of imaging, the calibrating process can support many subsequent tasks such as target detection. Experiments indicate that our method achieves the expected effect.

A new calibration method of camera arrays based on infinite scene registration for long-range infrared detection

“…Equation (15) indicates that the SNR of the infrared target should be improved by √𝐾 if the camera array composed of K cameras is used, which shows the advantages and potential of camera arrays in detecting infrared dim and small targets.…”

“…The model parameters of camera arrays can be calculated by establishing the projection relation between three-dimension space points on the calibrator and the corresponding pixel points in camera images. Based on the form of calibrators, the calibration methods can be classified as the one-dimension-calibrator-based method [11][12] , the two-dimension-calibrator-based method [13][14][15] , and the threedimension-calibrator-based method 16 . Because the closest clear imaging distance of the long-range infrared detection system with a long focal length is far, the calibrator-based method is difficult to place the calibrator within the imaging depth range of the infrared system.…”

An Infrared Camera Array Calibration Method using Constant Temperature Heating Checkboard

“…As the growing development of imaging technology, multi camera and camera array are used in more and more application [1][2][3][4][5]. Camera calibration plays an important role in the application of infrared camera array [6]. It aims to acquire camera imaging model parameters.…”

“…Wang et al [9] proposed a stereo calibration method for binocular ultra-wide angle long-wave infrared camera based on an equivalent small field of view camera. Xie et al [6] applied Zhang's model [8] to every single sub-camera of infrared camera array.…”