Mosaicking video with parallax.

Cheung Man-Tai.Thesis (M.Phil.)--Chinese University of Hong Kong, 2001.Includes bibliographical references (leaves 81-84).Abstracts in English and Chinese.List of Figures --- p.viList of Tables --- p.viiiChapter Chapter 1. --- Introduction --- p.1Chapter 1.1. --- Background --- p.1Chapter 1.1.1. --- Parallax --- p.2Chapter 1.2. --- Literature Review --- p.3Chapter 1.3. --- Research Objective --- p.6Chapter 1.4. --- Organization of Thesis --- p.6Chapter Chapter 2. --- The 3-Image Algorithm --- p.1Chapter 2.1. --- Projective Reconstruction --- p.10Chapter 2.2. --- Epipolar Geometry and Fundamental Matrix --- p.11Chapter 2.3. --- Determine the Projective Mapping --- p.12Chapter 2.3.1. --- Conditions for Initial Matches --- p.13Chapter 2.3.2. --- Obtaining the Feature Correspondence --- p.17Chapter 2.4. --- Registering Pixel Element --- p.21Chapter 2.4.1. --- Single Homography Approach --- p.22Chapter 2.4.2. --- Multiple Homography Approach --- p.23Chapter 2.4.3. --- Triangular Patches Clustering --- p.24Chapter 2.4.3.1. --- Delaunay Triangulation --- p.25Chapter 2.5. --- Mosaic Construction --- p.29Chapter Chapter 3. --- The n-Image Algorithm --- p.31Chapter Chapter 4. --- The Uneven-Sampling-Rate n-Image Algorithm --- p.34Chapter 4.1. --- Varying the Reference-Target Images Separation --- p.35Chapter 4.2. --- Varying the Target-Intermediate Images Separation --- p.38Chapter Chapter 5. --- Experiments --- p.43Chapter 5.1. --- Experimental Setup --- p.43Chapter 5.1.1. --- Measuring the Performance --- p.43Chapter 5.2. --- Experiments on the 3-Image Algorithm --- p.44Chapter 5.2.1. --- Planar Scene --- p.44Chapter 5.2.2. --- Comparison between a Global Parametric Transformation and the 3-Image Algorithm --- p.46Chapter 5.2.3. --- Generic Scene --- p.49Chapter 5.2.4. --- The Triangular Patches Clustering against the Multiple Homography Approach --- p.52Chapter 5.3. --- Experiments on the n-Image Algorithm --- p.56Chapter 5.3.1. --- Initial Experiment on the n-Image Algorithm --- p.56Chapter 5.3.2. --- Another Experiment on the n-Image Algorithm --- p.58Chapter 5.3.3. --- the n-Image Algorithm over a Longer Image Stream --- p.61Chapter 5.4. --- Experiments on the Uneven-Sampling-Rate n-Image Algorithm --- p.65Chapter 5.4.1. --- Varying Reference-Target Images Separation --- p.65Chapter 5.4.2. --- Varying Target-Intermediate Images Separation --- p.69Chapter 5.4.3. --- Comparing the Uneven-Sampling-Rate n-Image Algorithm and Global Transformation Method --- p.73Chapter Chapter 6. --- Conclusion and Discussion --- p.76Bibliography --- p.8

Parallax-Tolerant Image Stitching

Parallax handling is a challenging task for image stitch-ing. This paper presents a local stitching method to handle parallax based on the observation that input images do not need to be perfectly aligned over the whole overlapping re-gion for stitching. Instead, they only need to be aligned in a way that there exists a local region where they can be seam-lessly blended together. We adopt a hybrid alignment model that combines homography and content-preserving warp-ing to provide flexibility for handling parallax and avoiding objectionable local distortion. We then develop an efficient randomized algorithm to search for a homography, which, combined with content-preserving warping, allows for op-timal stitching. We predict how well a homography enables plausible stitching by finding a plausible seam and using the seam cost as the quality metric. We develop a seam finding method that estimates a plausible seam from only roughly aligned images by considering both geometric alignment and image content. We then pre-align input images using the optimal homography and further use content-preserving warping to locally refine the alignment. We finally compose aligned images together using a standard seam-cutting al-gorithm and a multi-band blending algorithm. Our exper-iments show that our method can effectively stitch images with large parallax that are difficult for existing methods. 1

Exploiting Structural Constraints in Image Pairs

Ph.DDOCTOR OF PHILOSOPH