The geometric distortions correction of uncooled large-sized relative aperture infrared imaging system

The geometric distortion of infrared image, which was created by the large-sized relative aperture optical system. It could be corrected by the digital image processing technology. The magnitude of distortion would be enlarged quickly with the enlargement of relative aperture. Though the distortion could not impact on the articulation of the image, it would affect geometric location precision of the image directly. In this paper, the distortion correction of uncooled large-sized relative aperture infrared imaging system was discussed and the mathematical model of distortion correction was established. A algorithm of digital image processing was presented and applied based on control points by combining polynomial warping and space variant linear image interpolation. The method of polynomial warping was used to establish the locality relationship between the original image and the distortion ones. The space-variant linear image interpolation provided an efficient way to rebuild the frame of images. The computational costs of the proposed approach are very little and the precision is almost as high as the method of bicubic interpolation when compared to those of state-of-the-art nonlinear interpolation operators