2,448 research outputs found
Assessment criteria for 2D shape transformations in animation
The assessment of 2D shape transformations (or morphing) for animation is a difficult task because it is a multi-dimensional problem. Existing morphing techniques pay most attention to shape information interactive control and mathematical simplicity. This paper shows that it is not enough to use shape information alone, and we should consider other factors such as structure, dynamics, timing, etc. The paper also shows that an overall objective assessment of morphing is impossible because factors such as timing are related to subjective judgement, yet local objective assessment criteria, e.g. based on shape, are available. We propose using âarea preservationâ as the shape criterion for the 2D case as an acceptable approximation to âvolume preservationâ in reality, and use it to establish cases in which a number of existing techniques give clearly incorrect results. The possibility of deriving objective assessment criteria for dynamics simulations and timing under certain conditions is discussed
Morphing the CMB: a technique for interpolating power spectra
The confrontation of the Cosmic Microwave Background (CMB) theoretical
angular power spectrum with available data often requires the calculation of
large numbers of power spectra. The standard practice is to use a fast code to
compute the CMB power spectra over some large parameter space, in order to
estimate likelihoods and constrain these parameters. But as the dimensionality
of the space under study increases, then even with relatively fast anisotropy
codes, the computation can become prohibitive. This paper describes the
employment of a "morphing" strategy to interpolate new power spectra based on
previously calculated ones. We simply present the basic idea here, and
illustrate with a few examples; optimization of interpolation schemes will
depend on the specific application. In addition to facilitating the exploration
of large parameter spaces, this morphing technique may be helpful for Fisher
matrix calculations involving derivatives.Comment: 18 pages, including 6 figures, uses elsart.cls, accepted for
publication in New Astronomy, changes to match published versio
Hybrid Evolutionary Shape Manipulation for Efficient Hull Form Design Optimisation
âEco-friendly shippingâ and fuel efficiency are gaining much attention in the maritime industry due to increasingly stringent environmental regulations and volatile fuel prices. The shape of hull affects the overall performance in efficiency and stability of ships. Despite the advantages of simulation-based design, the application of a formal optimisation process in actual ship design work is limited. A hybrid approach which integrates a morphing technique into a multi-objective genetic algorithm to automate and optimise the hull form design is developed. It is envisioned that the proposed hybrid approach will improve the hydrodynamic performance as well as overall efficiency of the design process
Interpolation between multi-dimensional histograms using a new non-linear moment morphing method
A prescription is presented for the interpolation between multi-dimensional
distribution templates based on one or multiple model parameters. The technique
uses a linear combination of templates, each created using fixed values of the
model's parameters and transformed according to a specific procedure, to model
a non-linear dependency on model parameters and the dependency between them. By
construction the technique scales well with the number of input templates used,
which is a useful feature in modern day particle physics, where a large number
of templates is often required to model the impact of systematic uncertainties.Comment: 20 pages, 6 figures. Algorithm publicly available in RooFi
Morphing of Triangular Meshes in Shape Space
We present a novel approach to morph between two isometric poses of the same
non-rigid object given as triangular meshes. We model the morphs as linear
interpolations in a suitable shape space . For triangulated 3D
polygons, we prove that interpolating linearly in this shape space corresponds
to the most isometric morph in . We then extend this shape space
to arbitrary triangulations in 3D using a heuristic approach and show the
practical use of the approach using experiments. Furthermore, we discuss a
modified shape space that is useful for isometric skeleton morphing. All of the
newly presented approaches solve the morphing problem without the need to solve
a minimization problem.Comment: Improved experimental result
An Image Morphing Technique Based on Optimal Mass Preserving Mapping
©2007 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or distribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.DOI: 10.1109/TIP.2007.896637Image morphing, or image interpolation in the time domain, deals with the metamorphosis of one image into another. In this paper, a new class of image morphing algorithms is proposed based on the theory of optimal mass transport. The 2 mass moving energy functional is modified by adding an intensity penalizing term, in order to reduce the undesired double exposure effect. It is an intensity-based approach and, thus, is parameter free. The optimal warping function is computed using an iterative gradient descent approach. This proposed morphing method is also extended to doubly connected domains using a harmonic parameterization technique, along with finite-element methods
- âŠ