Infrared and visible image registration using feature and area for image fusion

An image registration method is proposed in this paper for accurately aligning two images of the same scene captured simultaneously by visible CCD and IR (infrared) cameras. In image fusion systems, CCD and IR sensors are physically aligned as closely as possible and yet significant image mis-alignment remains due to differences in field of view, lens distortion and other camera characteristics. So, affine transformation is considered for aligning two images. At first, the corresponding feature point pairs are selected manually and that are used to calculate transform coefficients. Then, the value of the transform coefficients are optimized further by MI (mutual information) in global image. After the unregistered image is transformed by optimal transform coefficients, the accurately registered image can be obtained. The experimental results demonstrate that this method can provide highly accurate registered images for image fusion.