CHAIR: automatic image registration based on correlation and Hough transform

• Published in: International journal of remote sensing Vol. 33; no. 24; pp. 7936 - 7968
• Main Authors: Gonçalves, H, Gonçalves, J. A, Corte-Real, L, Teodoro, A. C
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 20.12.2012
• Subjects: Animal, plant and microbial ecology; Applied geophysics; Biological and medical sciences; computer vision; Earth sciences; Earth, ocean, space; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General aspects. Techniques; Internal geophysics; medicine; remote sensing; synthetic aperture radar; Teledetection and vegetation maps; Vertical; Spectral band; Hough transformation; Determination; Computing; Image; Correlation method; Result; evaluation; Field; Distance; direction; Image registration; Computer vision; processes; Satellite observation; remote sensing; quality; Type; concepts; corrections; correlation; Control point; Automatic; distortion
• ISSN: 1366-5901; 0143-1161; 1366-5901
• DOI: 10.1080/01431161.2012.701345

Automatic image registration is a process related to several application fields: remote sensing, medicine and computer vision, among others. Particularly in the field of remote sensing, the ever-increasing number of available satellite images requires automatic image registration methods, capable of correctly aligning a new image. An automatic image registration method – CHAIR (correlation- and Hough transform-based method of automatic image registration) – is proposed, the key concept of which relies on the ‘correlation image’ produced in both the horizontal and vertical directions. In particular, the computation of the distance of an identified diagonal brighter strip in the correlation image (through the Hough transform) to an offset (the main diagonal) allows for the determination of translational shifts and consequently control points. The set of obtained control points allows for the correction of several types of distortions. The geometric correction quality achieved by CHAIR was objectively evaluated through measures recently proposed, which allow for a more complete assessment of the obtained results. The CHAIR performance was evaluated on both synthetic and real data, with different spatial resolutions and spectral contents. CHAIR has been shown to be able to correctly align two images with a subpixel accuracy, having a priori a ‘gold standard’ image covering a considerable part of the image to be registered, and has also been shown to work for images of different sensors and/or different spectral bands, situations where traditional correlation methods often yield low and smooth peaks on the correlation surface. It is also able to account for elevation differences and to some extent for rotation and scale effects. Furthermore, it has been shown to have potential for registering synthetic aperture radar (SAR) with optical images.