THESIS
2014
xiv, 80 pages : illustrations ; 30 cm
Abstract
This thesis proposes new methods for creating continuous mappings between images and
videos, as well as the adaptive transition control schemes that create smooth transitions.
The main challenge in achieving good image morphs is to create a map that aligns corresponding
image elements. Our aim is to help automate this often tedious task. We compute the
map by optimizing the compatibility of corresponding warped image neighborhoods using an
adaptation of structural similarity. The optimization is regularized by a thin-plate spline, and
may be guided by a few user-specified points. We parameterize the map over a halfway domain
and show that this representation offers many benefits. The map is able to treat the image
pair symmetrically, model simple occlusions continuously, span...[
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This thesis proposes new methods for creating continuous mappings between images and
videos, as well as the adaptive transition control schemes that create smooth transitions.
The main challenge in achieving good image morphs is to create a map that aligns corresponding
image elements. Our aim is to help automate this often tedious task. We compute the
map by optimizing the compatibility of corresponding warped image neighborhoods using an
adaptation of structural similarity. The optimization is regularized by a thin-plate spline, and
may be guided by a few user-specified points. We parameterize the map over a halfway domain
and show that this representation offers many benefits. The map is able to treat the image
pair symmetrically, model simple occlusions continuously, span partially overlapping images,
and define extrapolated correspondences. Moreover, it enables direct evaluation of the morph
in a pixel shader without mesh rasterization. We improve the morphs by seamlessly extending
content beyond the image boundaries. We parallelize the algorithm on a GPU to achieve a
responsive interface and demonstrate challenging morphs obtained with little effort.
Extending image morphing techniques to video presents some added challenges. Because
motions are often unsynchronized, temporal alignment is necessary. Applying morphing to
individual frames leads to discontinuities, so temporal coherence must be considered. Our
approach is to optimize a full spatiotemporal mapping between the two videos. We reduce
tedious interactions by letting the optimization derive the fine-scale map given only sparse user-specified
constraints. For robustness, the optimization objective examines structural similarity
of the video content. We demonstrate the approach on a variety of videos, obtaining results
using few explicit correspondences.
After defining correspondence maps between two images (or videos) that align structurally
similar elements, the actual interpolation usually involves simple functions for both geometric
paths and color blending. Different from that, we further explore new types of controls for combining
two images related by a correspondence map. Our insight is to apply recent edge-aware
decomposition techniques, not just to the image content but to the map itself. Our framework
establishes an intuitive low-dimensional parameter space for merging the shape and color from
the two source images at both low and high frequencies. A gallery-based user interface enables
interactive traversal of this rich space, to either define a morph path or synthesize new
hybrid images. Extrapolation of the shape parameters achieves compelling effects. Finally we
demonstrate an extension of the framework to videos.
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