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Fast, Automatic, Topology-Preserving Gradient Mesh Generation for Image Vectorization
"... Figure 1: Vectorization of an amulet with 21 holes, using a single topology-preserving gradient mesh. Gradient mesh vector graphics representation, used in commercial software, is a regular grid with specified position and color, and their gradients, at each grid point. Gradient meshes can compactly ..."
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Figure 1: Vectorization of an amulet with 21 holes, using a single topology-preserving gradient mesh. Gradient mesh vector graphics representation, used in commercial software, is a regular grid with specified position and color, and their gradients, at each grid point. Gradient meshes can compactly represent smoothly changing data, and are typically used for single objects. This paper advances the state of the art for gradient meshes in several significant ways. Firstly, we introduce a topology-preserving gradient mesh representation which allows an arbitrary number of holes. This is important, as objects in images often have holes, either due to occlusion, or their 3D structure. Secondly, our algorithm uses the concept of image manifolds, adapting surface parameterization and fitting techniques to generate the gradient mesh in a fully automatic manner. Existing gradient-mesh algorithms require manual interaction to guide grid construction, and to cut objects with holes into disk-like regions. Our new algorithm is empirically at least 10 times faster than previous approaches. Furthermore, image segmentation can be used with our new algorithm to provide automatic gradient mesh generation for a whole image. Finally, fitting errors can be simply controlled to balance quality with storage.
1 Temporal coherent image segmentation and its applications
"... We propose a trapped-ball method for image segmentation, which is fast, supports non-uniformly colored regions, and allows robust region segmentation even in the presence of imperfectly linked region edges. We also introduce two applications by using the trapped-ball image segmentation, for temporal ..."
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We propose a trapped-ball method for image segmentation, which is fast, supports non-uniformly colored regions, and allows robust region segmentation even in the presence of imperfectly linked region edges. We also introduce two applications by using the trapped-ball image segmentation, for temporal coherent animations generation and editing. First, we present a system for vectorizing 2D raster format cartoon animations by the segmentation method and background construction. The output animations are visually flicker free, smaller in file size, and easy to edit. And then we present an automatic method for online video stream stylization, producing a temporally coherent output video stream, based on the trapped-ball segmentation and optical flow. Our system transforms video into an abstract style with large regions of constant color and highlighted bold edges. Key words: trapped-ball segmentation, cartoon vectorization, video stylization, optical flow 1.
Structure Preserving Manipulation and Interpolation for Multi-element 2D Shapes
"... This paper presents a method that generates natural and intuitive deformations via direct manipulation and smooth interpolation for multi-element 2D shapes. Observing that the structural relationships between different parts of a multi-element 2D shape are important for capturing its feature semanti ..."
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This paper presents a method that generates natural and intuitive deformations via direct manipulation and smooth interpolation for multi-element 2D shapes. Observing that the structural relationships between different parts of a multi-element 2D shape are important for capturing its feature semantics, we introduce a simple structure called a feature frame to represent such relationships. A constrained optimization is solved for shape manipulation to find optimal deformed shapes under user-specified handle constraints. Based on the feature frame, local feature preservation and structural relationship maintenance are directly encoded into the objective function. Beyond deforming a given multi-element 2D shape into a new one at each key frame, our method can automatically generate a sequence of natural intermediate deformations by interpolating the shapes between the key frames. The method is computationally efficient, allowing real-time manipulation and interpolation, as well as generating natural and visually plausible results.
6 Image Similarity Measurement using Shape Feature
"... In this paper, we describe an incipient method for image retrieval predicated on the local invariant shape feature, designated scalable shape context. The feature utilizes the Harris-Laplace corner to locat the fix points and coinside scale in the animal and flower image. Then, we utilize shape cont ..."
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In this paper, we describe an incipient method for image retrieval predicated on the local invariant shape feature, designated scalable shape context. The feature utilizes the Harris-Laplace corner to locat the fix points and coinside scale in the animal and flower image. Then, we utilize shape context to explain the local shape. Correspondence of feature points is achieved by a weighted bipartite graph matching algorithm and the homogeneous attribute between the query and the indexing image is presented by the match cost. The practical results show that our method is efficient than shape context and SIFT for the animal and flower image retrieval.
Video Stream Transmodality
"... Abstract: Transmodality is the partitioning of an image into regions that are expected to present a better entropy using different coding schemes, depending on their structural density, at constant bandwidth. In this paper we present the transmodality of video stream. Our contribution is a transmode ..."
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Abstract: Transmodality is the partitioning of an image into regions that are expected to present a better entropy using different coding schemes, depending on their structural density, at constant bandwidth. In this paper we present the transmodality of video stream. Our contribution is a transmoder module that includes various different optimized video codecs and implements the concept of transmodality on a set of video streams. We evaluate our proposal with different kinds of video (in content term), and our algorithm shows comprehensive results by saving up to 8 % of bandwidth for the same PSNR in comparison with the state-of-the-art video encoding baselines. 1
Vectorising Bitmaps into Semi-Transparent Gradient Layers
"... (c) Editing result(b) Multi-layer vector representation(a) Input photograph Figure 1: Our interactive vectorisation technique lets users vectorise an input bitmap (a) into a stack of opaque and semi-trans-parent vector layers composed of linear or radial colour gradients (b). Users can manipulate th ..."
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(c) Editing result(b) Multi-layer vector representation(a) Input photograph Figure 1: Our interactive vectorisation technique lets users vectorise an input bitmap (a) into a stack of opaque and semi-trans-parent vector layers composed of linear or radial colour gradients (b). Users can manipulate the resulting layers using standard tools to quickly produce new looks (c). We outline semi-transparent layers for visualisation; these edges are not part of our result. We rasterised figures to avoid problems with transparency in some PDF viewers. See supplemental material for vector graphics. We present an interactive approach for decompositing bitmap drawings and studio photographs into opaque and semi-transparent vector layers. Semi-transparent layers are especially challenging to extract, since they require the inversion of the non-linear compositing equation. We make this problem tractable by exploiting the parametric nature of vector gradients, jointly separating and vectorising semi-transparent regions. Specifically, we constrain the foreground colours to vary according to linear or radial parametric gradients, restricting the number of unknowns and allowing our system to efficiently solve for an editable semi-transparent foreground. We propose a progressive workflow, where the user successively selects a semi-transparent or opaque region in the bitmap, which our algorithm separates as a foreground vector gradient and a background bitmap layer. The user can choose to decompose the background further or vectorise it as an opaque layer. The resulting layered vector representation allows a variety of edits, such as modifying the shape of highlights, adding texture to an object or changing its diffuse colour. 1.
Recognizing Text Elements for SVG Comic Compression and its Novel Applications
, 2016
"... All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately. ..."
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All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.
Computer-Aided Design ( ) – Contents lists available at ScienceDirect Computer-Aided Design
"... journal homepage: www.elsevier.com/locate/cad A collaborative platform for integrating and optimising Computational Fluid ..."
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journal homepage: www.elsevier.com/locate/cad A collaborative platform for integrating and optimising Computational Fluid
