tailieunhanh - Stereo Vision_2

The book presents a wide range of innovative research ideas and current trends in stereo vision. The topics covered in this book encapsulate research trends from fundamental theoretical aspects of robust stereo correspondence estimation to the establishment of novel and robust algorithms as well as applications in a wide range of disciplines. | 11 A Stereo Vision Framework for 3-D Underwater Mosaicking A. Leone G. Diraco and C. Distante Institute for Microelectronics and Microsystems National Research Council Lecce Italy 1. Introduction Research on automatic mosaic creation for underwater applications has been investigated in the last fifteen years. The reconstruction of complex 3-D structures is useful in several underwater applications in particular 3-D mosaicking constitutes an important tool for seabed exploration improving visualization and navigation in the underwater medium. Moreover underwater measurement systems have been used extensively in marine research to estimate the size of interesting objects such as organisms and structures. In addition visual sensing can be an enabling technology for Autonomous Underwater Vehicles AUVs which have the critical requirement to maintain an ongoing representation of its relative position with respect to an environmental representation. In these contexts a better perception of the underwater environment can be achieved by using image processing algorithms for a suitable representation of the seabed. In optic sensing field and underwater environment shape acquisition concerns with sensing activity including Shape from Stereopsis Shape from Photometric Stereo Shape from Motion and Active Stereo. Main aspects about Shape from Stereopsis will be presented focusing the attention on synchronism in the acquisition at hardware software levels. The usage of triggered expensive equipments in synchronized stereo sequence acquisitions could present some technical limitations such as low frame rate and poor images resolution demoting the quality of the 3-D mosaic. For the previous reasons an ad-hoc algorithmic solution will be detailed to limit asynchronism problems due to time gap delay in stereo frames acquisition when low-cost non-professional non-triggered hardware is used. To achieve a metric reconstruction the presented framework requires a calibration phase whereas