George Wolberg | City College of New York (original) (raw)
Papers by George Wolberg
Proceedings of the 22nd annual conference on Computer graphics and interactive techniques - SIGGRAPH '95, 1995
This paper presents new solutions to the following three problems in image morphing: feature spec... more This paper presents new solutions to the following three problems in image morphing: feature specification, warp generation, and transition control. To reduce the burden of feature specification, we first adopt a computer vision technique called snakes. We next propose the use of multilevel free-form deformations (MFFD) to achieve C 2 -continuous and one-to-one warps among feature point pairs.
IEEE Transactions on Visualization and Computer Graphics, 1997
This paper describes a fast algorithm for scattered data interpolation and approximation. Multile... more This paper describes a fast algorithm for scattered data interpolation and approximation. Multilevel B-splines are introduced to compute a C 2 -continuous surface through a set of irregularly spaced points. The algorithm makes use of a coarse-tofine hierarchy of control lattices to generate a sequence of bicubic B-spline functions whose sum approaches the desired interpolation function. Large performance gains are realized by using B-spline refinement to reduce the sum of these functions into one equivalent B-spline function. Experimental results demonstrate that high-fidelity reconstruction is possible from a selected set of sparse and irregular samples.
IEEE Transactions on Visualization and Computer Graphics, 1996
This paper describes an image metamorphosis technique to handle scattered feature constraints spe... more This paper describes an image metamorphosis technique to handle scattered feature constraints specified with points, polylines, and splines. Solutions to the following three problems are presented: feature specification, warp generation, and transition control. We demonstrate the use of snakes to reduce the burden of feature specification. Next, we propose the use of multilevel freeform deformations (MFFD) to compute C 2 -continuous and one-to-one mapping functions among the specified features. The resulting technique, based on B-spline approximation, is simpler and faster than previous warp generation methods. Furthermore, it produces smooth image transformations without undesirable ripples and foldovers. Finally, we simplify the MFFD algorithm to derive transition functions to control geometry and color blending. Implementation details are furnished and comparisons among various metamorphosis techniques are presented.
IEEE Computer Graphics and Applications, 1998
This paper presents polymorph, a novel algorithm for morphing among multiple images. Traditional ... more This paper presents polymorph, a novel algorithm for morphing among multiple images. Traditional image morphing generates a sequence of images depicting an evolution from one image into another. We extend this approach to permit morphed images to be derived from more than two images at once.
IEEE Computer Graphics and Applications, 1998
This paper presents polymorph, a novel algorithm for morphing among multiple images. Traditional ... more This paper presents polymorph, a novel algorithm for morphing among multiple images. Traditional image morphing generates a sequence of images depicting an evolution from one image into another. We extend this approach to permit morphed images to be derived from more than two images at once. We formulate each input image to be a vertex of a simplex. An inbetween,
Proceedings of the 22nd annual conference on Computer graphics and interactive techniques - SIGGRAPH '95, 1995
This paper presents new solutions to the following three problems in image morphing: feature spec... more This paper presents new solutions to the following three problems in image morphing: feature specification, warp generation, and transition control. To reduce the burden of feature specification, we first adopt a computer vision technique called snakes. We next propose the use of multilevel free-form deformations (MFFD) to achieve C 2 -continuous and one-to-one warps among feature point pairs.
IEEE Transactions on Visualization and Computer Graphics, 1997
This paper describes a fast algorithm for scattered data interpolation and approximation. Multile... more This paper describes a fast algorithm for scattered data interpolation and approximation. Multilevel B-splines are introduced to compute a C 2 -continuous surface through a set of irregularly spaced points. The algorithm makes use of a coarse-tofine hierarchy of control lattices to generate a sequence of bicubic B-spline functions whose sum approaches the desired interpolation function. Large performance gains are realized by using B-spline refinement to reduce the sum of these functions into one equivalent B-spline function. Experimental results demonstrate that high-fidelity reconstruction is possible from a selected set of sparse and irregular samples.
IEEE Transactions on Visualization and Computer Graphics, 1996
This paper describes an image metamorphosis technique to handle scattered feature constraints spe... more This paper describes an image metamorphosis technique to handle scattered feature constraints specified with points, polylines, and splines. Solutions to the following three problems are presented: feature specification, warp generation, and transition control. We demonstrate the use of snakes to reduce the burden of feature specification. Next, we propose the use of multilevel freeform deformations (MFFD) to compute C 2 -continuous and one-to-one mapping functions among the specified features. The resulting technique, based on B-spline approximation, is simpler and faster than previous warp generation methods. Furthermore, it produces smooth image transformations without undesirable ripples and foldovers. Finally, we simplify the MFFD algorithm to derive transition functions to control geometry and color blending. Implementation details are furnished and comparisons among various metamorphosis techniques are presented.
IEEE Computer Graphics and Applications, 1998
This paper presents polymorph, a novel algorithm for morphing among multiple images. Traditional ... more This paper presents polymorph, a novel algorithm for morphing among multiple images. Traditional image morphing generates a sequence of images depicting an evolution from one image into another. We extend this approach to permit morphed images to be derived from more than two images at once.
IEEE Computer Graphics and Applications, 1998
This paper presents polymorph, a novel algorithm for morphing among multiple images. Traditional ... more This paper presents polymorph, a novel algorithm for morphing among multiple images. Traditional image morphing generates a sequence of images depicting an evolution from one image into another. We extend this approach to permit morphed images to be derived from more than two images at once. We formulate each input image to be a vertex of a simplex. An inbetween,