Electro-optics and Infrared Image Registration using Gaussian Pyramids Hyeok-Gi Gwon, Ik-Hyun Lee, and Tae-Sun Choi School of Mechatronics, Gwangju Institute of Science and Technology (GIST), 123 Cheomdan Gwagiro, Buk-Gu, Gwangju, 500-712, Republic of Korea {regret66,ihlee,tschoi}@gist.ac.kr http://sipl.gist.ac.kr Abstract. Image registration is a spatial alignment of two or more im- ages and essential technology in image fusion, surveillance. Unlike the electro-optics (EO) sensor, infrared (IR) sensor absorbs the radiation energy. The relation between IR and EO image of pixel intensity is sometimes similar or often reverse. To overcome this complicated prob- lem, we propose block-based processing incorporating corner detector and descriptor. This method also uses the Gaussian pyramids to register EO/IR image. The proposed method provides more accurate registration results. Keywords: Image registration, Gaussian pyramids, Feature extraction 1 Introduction In particular, image registration is considerably important technique in remote sensing, image fusion system, and surveillance. Image registration is a spatial alignment of the same area acquired from same or different times, views and sensors (reference and sensed image). Electro-optics (EO) image is acquired by using reflection and radiation of visible rays, whereas infrared (IR) image is use to absorb the radiation of energy and temperature information. Generally, single- modal registration is commonly used for many applications with visible range sensors during day and in indoor environments. In multi-modal case, infrared sensors were used in special medical imaging or and night vision. In surveillance system and remote sensing, infrared sensors provide more information than EO sensors in condition of poor lighting, smoke, fog, and cloudy weather. According to the different characteristics, using the both EO/IR sensors are more effective and each compensative. EO sensors are better than IR sensor during the day, while IR sensors provide more information in the dark. The drawback of using two sensors at same time is hard to extract corresponding features due to the complicated pixel intensity relation. It has sometimes similar intensity, while often reverse. Moreover, the contrast of IR image is less than EO image. In the literature [7], feature-based methods is recommended to use in remote sensing which has lots of information, whereas area-based methods are employed Advanced Science and Technology Letters Vol.29 (SIP 2013), pp.55-59 http://dx.doi.org/10.14257/astl.2013.29.11 ISSN: 2287-1233 ASTL Copyright © 2013 SERSC