Shadow metamorphosis

Any two objects A and B can be viewed as two different projections of their Cartesian product A×B. Rotating and projecting A×B results in a continuous transformation of A into B. During certain rotations, the contour of the Cartesian product remains the same although its projection changes. Based on these properties, we derive a fast and simple morphing algorithm without topological constraints on either object.     

DMorph [image metamorphosis]

Image morphing is an artist-driven process. A creative human being looks at the images (or sequences) to be bridged and determines a way to make the changes that will be pleasing to the viewer and harmonious with the piece. To help these artists, I've developed a technique for automatically and smoothly turning one convex 3D shape into another. Like any automatic morph method, this technique should be viewed as a tool and not a self-guided process. DMorph has pros and cons. On the pro side, it is satisfyingly simple and robust and easy to program. It doesn't place any constraints on the two objects being interpolated except that they're convex. One object can be a 200-sided cone where 200 polygons all share a single vertex, and the other object a baseball, and the algorithm doesn't care. There's no feature matching, automatic or otherwise. The transformations are smooth, and the blending looks nice. On the con side, the program is limited to convex objects.     

Processor reconfiguration through instruction-set metamorphosis

The processor reconfiguration through instruction-set metamorphosis (PRISM) general-purpose architecture, which speeds up computationally intensive tasks by augmenting the core processor's functionality with new operations, is described. The PRISM approach adapts the configuration and fundamental operations of a core processing system to the computationally intensive portions of a targeted application. PRISM-1, an initial prototype system, is described, and experimental results that demonstrate the benefits of the PRISM concept are presented     

Image metamorphosis with scattered feature constraints

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 free-form deformations (MFFD) to compute C²-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     

Volume-based three-dimensional metamorphosis using sphere-guided region correspondence

surface metamorphosis extends this paradigm by interpolating between discrete volume representations of the surfaces. The insensitivity of the established techniques to the surface topology enables morphing between completely different surfaces: however it can also lead to intermediate surfaces which have different topology from the originals. We present a method which improves on this situation by ensuring that no part of each surface remains disconnected during the morph. The morph is guided by region correspondence, derived automatically from a sphere representation of each surface: this can be combined with manual correspondence to retain user control over the morph. What emerges is a fast and flexible method for morphing surfaces, as demonstrated on several examples. Published online: 19 July 2001     

Robust image metamorphosis immune from ghost and blur

In this paper, we propose a novel method for the metamorphosis between two different images. By the approach, the transition sequence is generated by stitching two forward and backward warped sequences in a three-dimensional space along transition surface. In contrast to the traditional methods by blending two warped images at each intermediate frame, we continuously warp images on opposite direction without blending until the two warped images match in a three-dimensional space leading to a better transition in quality. Furthermore, for each pixel, we make decision of choosing a given input image best suitable so as to produce plausible in-between images to prevent from ghost and blur. By our scheme, the transition surface is computed by minimizing an energy function in terms of graph-cut optimization. Depending on the transition surface, a warp function is proposed to create a smooth and clear transformation. We demonstrate the advantage of our framework by performing transformation test to various kinds of image couples.     

3D shape metamorphosis based on T-spline level sets

We propose a new method for 3D shape metamorphosis, where the in-between objects are constructed by using T-spline scalar functions. The use of T-spline level sets offers several advantages: First, it is convenient to handle complex topology changes without the need of model parameterization. Second, the constructed objects are smooth (C² in our case). Third, high quality meshes can be easily obtained by using the marching triangulation method. Fourth, the distribution of the degrees of freedom can be adapted to the geometry of the object. Given one source object and one target object, we firstly find a global coordinate transformation to approximately align the two objects. The T-spline control grid is adaptively generated according to the geometry of the aligned objects, and the initial T-spline level set is found by approximating the signed distance function of the source object. Then we use an evolution process, which is governed by a combination of the signed distance function of the target object and a curvature-dependent speed function, to deform the T-spline level set until it converges to the target shape. Additional intermediate objects are inserted at the beginning/end of the sequence of generated T-spline level sets, by gradually projecting the source/target object to the initial/final T-spline level set. A fully automatic algorithm is developed for the above procedures. Experimental results are presented to demonstrate the effectiveness of our method.     

A level-set approach for the metamorphosis of solid models

We present a new approach to 3D shape metamorphosis. We express the interpolation of two shapes as a process where one shape deforms to maximize its similarity with another shape. The process incrementally optimizes an objective function while deforming an implicit surface model. We represent the deformable surface as a level set (iso-surface) of a densely sampled scalar function of three dimensions. Such level-set models have been shown to mimic conventional parametric deformable surface models by encoding surface movements as changes in the grayscale values of a volume data set. Thus, a well-founded mathematical structure leads to a set of procedures that describes how voxel values can be manipulated to create deformations that are represented as a sequence of volumes. The result is a 3D morphing method that offers several advantages over previous methods, including minimal need for user input, no model parameterization, flexible topology, and subvoxel accuracy     

Detection and classification of topological evolution for linear metamorphosis

The advantage of functional methods for shape metamorphosis is the automatic generation of intermediate shapes possible between the key shapes of different topology types. However, functional methods have a serious problem: shape interpolation is applied without topological information and thereby the time values of topological changes are not known. Thus, it is difficult to identify the time intervals for key frames of shape metamorphosis animation that faithfully visualize the topological evolution. Moreover, information on the types of topological changes is missing. To overcome the problem, we apply topological analysis to functional linear shape metamorphosis and classify the type of topological evolution by using a Hessian matrix. Our method is based on Morse theory and analyzes how the critical points appear. We classify the detected critical points into maximum point, minimum point, and saddle point types. Using the types of critical points, we can define the topological information for shape metamorphosis. We illustrate these methods using shape metamorphosis in 2D and 3D spaces.     

Bilinear interpolation for facial expression and metamorphosis in real-time animation

This paper describes a new method for generating facial animation in which facial expression and shape can be changed simultaneously in real time. A 2D parameter space independent of facial shape is defined, on which facial expressions are superimposed so that the expressions can be applied to various facial shapes. A facial model is transformed by a bilinear interpolation, which enables a rapid change in facial expression with metamorphosis. The practical efficiency of this method has been demonstrated by a real-time animation system based on this method in live theater.     

Fast and intuitive metamorphosis of 3D polyhedral models using SMCC mesh merging scheme

A very fast and intuitive approach to generate the metamorphosis of two genus 0 3D polyhedral models is presented. There are two levels of correspondence specified by animators to control morphs. The higher level requires the animators to specify scatter features to decompose the input models into several corresponding patches. The lower level optionally allows the animators to specify extra features on each corresponding patch for finer correspondence control. Once these two levels of correspondence are established, the proposed schemes automatically and efficiently establish a complete one-to-one correspondence between two models. We propose a novel technique called SMCC (Structures of Minimal Contour Coverage) to efficiently and robustly merge corresponding embeddings. The SMCC scheme can compute merging in linear time. The performance of the proposed methods is comparable to or better than state-of-the-art 3D polyhedral metamorphosis. We demonstrate several examples of aesthetically pleasing morphs, which can be created very quickly and intuitively.     

Model interoperability via Model Driven Development

Among the factors that contribute to the inherent complexity of the software development process is the gap between the design and the formal analysis domains. Software design is often considered a human oriented task while the analysis phase draws on formal representation and mathematical foundations. An example of this dichotomy is the use of UML for the software design phase and Petri Nets for the analysis; a separation of concerns that leads to the creation of heterogeneous models. Although UML is widely accepted as a language that can be used to model the structural and behavioural aspects of a system, its lack of mathematical foundations is seen as a serious impediment to rigorous analysis. Petri Nets on the other hand have a strong mathematical basis that are well suited for formal analysis; they lack however the appeal and the ease-of-use of UML. A pressing concern for software developers is how to bridge the gap between these domains and allow for model interoperability and the integration of different toolsets across them, and thus reduce the complexity of the software development process. The aim of this paper is to present a Model Driven Development (MDD) model transformation which supports a seamless transition between UML and Petri Nets. This is achieved by model interoperability from UML Sequence Diagrams to Petri Nets and supported by tool integration. The model transformation framework allows a software system to be designed in terms of UML Sequence Diagrams and subjected to formal analysis by taking advantage of the strong mathematical framework of Petri Nets. The behaviour of a Personal Area Network will be used to illustrate the proposed approach and to highlight model interoperability and tool integration through the design, the transformation and the analysis phases.     

一种可用于数据和模型分享的模型链

机器学习开始在越来越多的行业中得到应用,但使用机器学习执行任务的软件一直受限于第三方软件商更新模型.文中基于区块链,将训练神经网络消耗的算力和区块链的工作量证明机制相结合,提出并实现了模型链.模型链作为一种可用于分享数据和机器学习模型的区块链,基于骨架网络训练神经网络模型,以全网节点匿名分享的数据作为训练模型的数据集,实现了不依赖第三方更新神经网络模型.模型链使用环签名来保护用户数据隐私,节点训练的模型使用统一的测试集评估,通过评估的模型将作为节点的工作量证明用于投票达成一致共识.文中提出了两种可行的激励机制,即物质奖励和模型奖励.对于潜在的威胁,如账本分析、脏数据攻击和欺骗投票,给出了相应的解决方案.实现了一个用于数字识别的模型链.实验结果表明,模型链中的模型可以适应实际场景下发生的用户变迁和数据变化.     

从面向对象模型到关系模型

文章首先概述了面向对象模型设计的方法,然后着重讨论了将面向对象模型转换为关系模型及关系模型优化的问题,最后给出一个应用实例。     

一种可用于数据和模型分享的模型链

机器学习开始在越来越多的行业中得到应用,但使用机器学习执行任务的软件一直受限于第三方软件商更新模型.文中基于区块链,将训练神经网络消耗的算力和区块链的工作量证明机制相结合,提出并实现了模型链.模型链作为一种可用于分享数据和机器学习模型的区块链,基于骨架网络训练神经网络模型,以全网节点匿名分享的数据作为训练模型的数据集,实现了不依赖第三方更新神经网络模型.模型链使用环签名来保护用户数据隐私,节点训练的模型使用统一的测试集评估,通过评估的模型将作为节点的工作量证明用于投票达成一致共识.文中提出了两种可行的激励机制,即物质奖励和模型奖励.对于潜在的威胁,如账本分析、脏数据攻击和欺骗投票,给出了相应的解决方案.实现了一个用于数字识别的模型链.实验结果表明,模型链中的模型可以适应实际场景下发生的用户变迁和数据变化.     

一种数据仓库的概念模型-样本模型

数据仓库概念模型设计是数据仓库设计和实施的基础,是决定数据仓库成功与否的关键之一。该文介绍了一种数据仓库的概念模型-样本模型,它以事件为中心组织实体,并给出了描述实体之间层次、分类、组合关系的方法,以及确定样本库模式的原则和方法。最后给出了从ER模型向样本模型转换的方法。     

工作流模型的模型检验技术研究

传统的工作流模型校核方法存在效率低下、自动化程度不高的缺陷,针对该问题模型检验技术被引入工作流模型校核.该文在探讨模型检验技术基础之上,采用UML活动图表示工作流过程模型,根据模型检验技术的要求研究了工作流模型从无限到有限状态空间的转换,对工作流模型检验对强公正约束的要求进行了初步研究,并结合NuSMV分析了如何实施工作流模型检验.该文进一步通过一个案例给出了工作流模型检验的实施,在此基础上该文认为模型检验有助于提高模型校核效率,从而提高工作流模型质量.