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11
Manipulation and Compositing of MCDCT Compressed Video
, 1994
"... Many advanced video applications require manipulations of compressed video signals. Popular video manipulation functions include overlap (opaque or semitransparent), translation, scaling, linear filtering, rotation, and pixel multiplication. In this paper, we propose algorithms to manipulate compre ..."
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Cited by 94 (16 self)
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Many advanced video applications require manipulations of compressed video signals. Popular video manipulation functions include overlap (opaque or semitransparent), translation, scaling, linear filtering, rotation, and pixel multiplication. In this paper, we propose algorithms to manipulate compressed video in the compressed domain. Specifically, we focus on compression algorithms using the Discrete Cosine Transform (DCT) with or without Motion Compensation (MC). Compression systems of such kind include JPEG, Motion JPEG, MPEG, and H.261. We derive a complete set of algorithms for all aforementioned manipulation functions in the transform domain, in which video signals are represented by quantized transform coefficients. Due to a much lower data rate and the elimination of decompression/compression conversion, the transformdomain approach has great potential in reducing the computational complexity. The actual computational speedup depends on the specific manipulation functions and ...
Implementation Techniques for Continuous Media Systems and Applications
, 1994
"... In this thesis, I investigate issues in the development of continuous media (CM) applications. CM applications process, transport, or store CM data such as digital audio and video. Introduction of video into applications will require support for sophisticated video effects such as image processing ..."
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Cited by 36 (4 self)
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In this thesis, I investigate issues in the development of continuous media (CM) applications. CM applications process, transport, or store CM data such as digital audio and video. Introduction of video into applications will require support for sophisticated video effects such as image processing, composition and digital filtering. Traditional image processing and composition algorithms operate on uncompressed images, while video is typically stored and delivered in a compressed form. High computational cost, along with the complexity of video decompression, makes traditional algorithms too slow for interactive use on video data. This thesis describes and evaluates a new family of algorithms for computing video effects that run one to two orders of magnitude faster than their ...
Logic of Global Synchrony
, 2001
"... An intermediatelevel specification notation is presented for use with BSPstyle programming. It is achieved by extending prepost semantics to reveal state at points of global synchronisation. That enables us to integrate the prepost, finite and reactiveprocess styles of specification in BSP, as ..."
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Cited by 14 (10 self)
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An intermediatelevel specification notation is presented for use with BSPstyle programming. It is achieved by extending prepost semantics to reveal state at points of global synchronisation. That enables us to integrate the prepost, finite and reactiveprocess styles of specification in BSP, as shown by our treatment of the dining philosophers. The language is provided with a complete set of laws and has been formulated to benefit from a simple predicative semantics.
Compressed Domain Transcoding of MPEG
, 1998
"... Current video compression formats optimize for either compression or editing. For example, motionJPEG (MJPEG) provides excellent random access and moderate overall compression, while MPEG optimizes for compression at the expense of random access. Converting from one format to another, a process cal ..."
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Cited by 12 (3 self)
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Current video compression formats optimize for either compression or editing. For example, motionJPEG (MJPEG) provides excellent random access and moderate overall compression, while MPEG optimizes for compression at the expense of random access. Converting from one format to another, a process called transcoding, is often desirable over the life of a video segment. This paper shows how to transcode MPEG1 video to motionJPEG without fully decompressing the MPEG1 source. The described technique for compressed domain transcoding differs from previous work because it uses a new approximation approach that is optimized for software implementations. This new approach is 1.5 to 3 times faster than spatial domain transcoders and offers an additional degree of freedom: higher transcoding speeds can be obtained at the price of lower picture quality. This speed/quality tradeoff is useful in many realtime applications such as offline editing and video gateways. 1. Introduction MotionJPE...
A fixpoint theory for nonmonotonic parallelism
, 2002
"... This paper studies parallel recursion. The trace specification language used in this paper incorporates sequential,j nondeterminism, reactiveness(inclvenessg,F'k traces), three forms of paral'VgJj (inclVgJjqMkEglglgl fairinterlkEglgl synchronous paralonousg and general recursion. In order to use Ta ..."
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Cited by 8 (5 self)
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This paper studies parallel recursion. The trace specification language used in this paper incorporates sequential,j nondeterminism, reactiveness(inclvenessg,F'k traces), three forms of paral'VgJj (inclVgJjqMkEglglgl fairinterlkEglgl synchronous paralonousg and general recursion. In order to use Tarski's theorem to determine the fixpoints of recursions, we need to identify awelVjgJ,FIq partial order.Several orders are considered,incldered new order calrg the lexical order, which tends tosimulM, the execution of a recursion in asimilk manner as the EglVqgJ,E, order. A theorem of this paper shows that no appropriate order exists for the lhegIIIE Tarski's theoremalor is not enough to determine the fixpoints ofparalVI recursions. Instead of usingTarski's theoremdirectl, we reason about the fixpoints of terminatingand nonterminatingbehavioursseparateli Such reasoningis supported by the leg of a new compositioncalio partition. We propose a fixpoint techniquecalni the partitioned fixpoint, which is thelgqk fixpoint of the nonterminatingbehaviours after the terminatingbehaviours reach their greatest fixpoint. The surprisingresul is thataltg,M, a recursion may not beljV"EgJqVE' monotonic, it must have the partitioned fixpoint, which isequal to thelegj lgjIjI,gJqF' fixpoint. Since the partitioned #xpoint iswel defined in anycompl,q lmpl,q theresulq areappljFMgJ to various semanticmodeli Existing fixpoint techniques simpl becomespecial cases of the partitioned fixpoint. Forexamplj an EglIIqgJq',EFglEFg recursion has itslsgj EglMMFIgJq fixpoint, which can be shown to be the same as the partitioned fixpoint. The new technique is moregeneral than thelegq EglEEkIgJq fixpoint in that the partitioned fixpoint can be determined even when a recursion is notEglVjjVgJq monotonic.Exampln of nonmonotonic recur...
Integrating Temporal Logics
, 2004
"... In this paper, we study the predicative semantics of different temporal logics and the relationships between them. We use a notation called generic composition to simplify the manipulation of predicates. The modalities of possibility and necessity become generic composition and its inverse of conver ..."
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Cited by 7 (3 self)
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In this paper, we study the predicative semantics of different temporal logics and the relationships between them. We use a notation called generic composition to simplify the manipulation of predicates. The modalities of possibility and necessity become generic composition and its inverse of converse respectively. The relationships between different temporal logics are also characterised as such modalities. Formal reasoning is carried out at the level of predicative semantics and supported by the higherlevel laws of generic composition and its inverse. Various temporal domains are unified under a notion called resource cumulation. Temporal logics based on these temporal domains can be readily defined, and their axioms identified. The formalism provides a framework in which human experience about system development can be formalised as refinement laws. The approach is demonstrated in the transformation from Duration Calculus to Temporal Logic of Actions. A number of common design patterns are studied. The refinement laws identified are then applied to the case study of water pump controlling.
Compositional Reasoning for Pointer Structures
 Proc. of 8th International Conference on Mathematics of Program Construction (MPC06
, 2006
"... Canonical trace model of Hoare and He supports a satisfactory theory of graph properties. We use it to define a technique for the general composition of properties that extends the parallelbymerge of Unifying Theories of Programming, and apply that to unique decompositions. ..."
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Cited by 5 (1 self)
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Canonical trace model of Hoare and He supports a satisfactory theory of graph properties. We use it to define a technique for the general composition of properties that extends the parallelbymerge of Unifying Theories of Programming, and apply that to unique decompositions.
Hierarchical Organisation of PredicateSemantic Models
 of Lecture Notes in Computer Science
, 2006
"... This paper introduces techniques to organise predicatesemantic models in a hierarchical structure so that a new model can inherit the laws of more abstract ones. Generic composition is used to simplify the manipulation of predicates. Necessary restrictions are imposed on the definition of each ..."
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Cited by 3 (2 self)
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This paper introduces techniques to organise predicatesemantic models in a hierarchical structure so that a new model can inherit the laws of more abstract ones. Generic composition is used to simplify the manipulation of predicates. Necessary restrictions are imposed on the definition of each model so that the inheritance relation can be established by checking a few conditions on the healthiness conditions and the commands.
From Durational Specifications to TLA Designs of Timed Automata
 IN PROCEEDINGS OF ICFEM04, LECTURE NOTES IN COMPUTER SCIENCE, SEATLE
, 2004
"... Different temporal logics tend to emphasise different aspects of a hybrid system. In this paper, we study the predicative interpretation of Duration Calculus (DC) and Temporal Logic of Actions (TLA) and the link between them. A notation called generic composition is used to simplify the manipulation ..."
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Cited by 3 (1 self)
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Different temporal logics tend to emphasise different aspects of a hybrid system. In this paper, we study the predicative interpretation of Duration Calculus (DC) and Temporal Logic of Actions (TLA) and the link between them. A notation called generic composition is used to simplify the manipulation of predicates. The modalities of possibility and necessity become generic composition and its inverse of converse respectively. The transformation between different temporal logics is also characterised as such modalities. The formalism provides a framework in which human experience about hybrid system development can be formalised as refinement laws. A highlevel durational specification can be decomposed to two durational specifications driven by an automaton. In such a stepwise design process, durational features are reduced while automaton features increase gradually. The application of the technique is demonstrated in the case study of the gas burner problem.
Baxter algebras and the umbral calculus
, 2004
"... We apply Baxter algebras to the study of the umbral calculus. We give a characterization of the umbral calculus in terms of Baxter algebra. This characterization leads to a natural generalization of the umbral calculus that include the classical umbral calculus in a family of λumbral calculi parame ..."
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Cited by 3 (3 self)
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We apply Baxter algebras to the study of the umbral calculus. We give a characterization of the umbral calculus in terms of Baxter algebra. This characterization leads to a natural generalization of the umbral calculus that include the classical umbral calculus in a family of λumbral calculi parameterized by λ in the base ring.