特集 マルチメディア時代の画像処理 フレーム間統合による高精細ディジタル画像の獲得

Abstract

When an object in a scene is moving slowly and/or the camera is being moved, the observed image sequence contains rich information about both the moving object and the scene. In this case, it seems that we can enhance spatial resolution within a region of interest in the observed image frame by integrating pixels over multiple observed image frames. The interframe-integration task involves a method for estimating interframe pixel correspondence with real pixel accuracy. The principal existing block-matching algorithm can provide highly accurate correspondence estimates only in the case in which a rigid object undergoes translation in a direction parallel to the image plane, it cannot cope with more general types of motion such as rotation. Standard gradient-based algorithms cannot stably provide accurate correspondence estimates for real moving images. In this paper, we present a method for estimating interframe pixel correspondence with real pixel accuracy. The system uses iteratively warping quadrilateral patches covering the region of interest, and is an interframe integration method. Experimental simulations conducted on real moving image sequences demonstrate that the proposed method enhances spatial resolution considerably when a region of interest is limited to one planar surface of an object.