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The notion of clique-width for graphs is a relatively new topic which has received attention in the past decade. A graph has bounded clique-width if it can be represented as an algebraic expression on a constant number of labels associated with its vertices. Many computationally hard problems can be solved in polynomial time for graphs with bounded clique-width. Interestingly also, many graph families...
Different from conventional profiles in the state-of-the-art video coding standard HEVC and related optimization methods, we focus on building the optimally scalable algorithms under constrained and varying computational capacity to take full advantages of HEVC as far as possible in order to meet the growing demands of computational capacity adaptive applications such as real-time video communication...
Fischer and Heun [SICOMP 2011] proposed the first Range Minimum Query (RMQ) data structure on an array A[1, n] that uses 2n + o(n) bits and answers queries in O(1) time without accessing A. Their scheme converts the Cartesian tree of A into a general tree, which is represented using DFUDS. We show that, by using instead the BP representation, the formula becomes simpler since border conditions are...
In this paper a lossless compression method for hyperspectral image is given. RKLT-based scheme was first presented by combining with 3D prediction, principal component selection, positive mapping followed by a range coder. The proposed method avoids the float number of coefficient which can make it much more easier to be processed on hardware. Numerical experiments show that the proposed method outperforms...
JPEG 2000 is an image coding system based on the discrete wavelet transform. Unfortunately, there exist several major issues with the effective implementation of the codec. For high resolution data decomposed by a separable transform, immensely many CPU cache misses occur. Following the procedure as defined in the standard, the coefficients of a single resolution appears all at once. Consequently,...
The High Efficiency Video Coding (HEVC) standard roughly doubles the rate-distortion compression performance of its predecessor, H.264/AVC, at a cost of a high computational complexity. Moreover, intra sequences are commonly used at video editing or post-production, making it necessary a migration from H.264/AVC to HEVC. This paper aims to propose a fast intra transcoding algorithm from H.264/AVC...
In many video coding systems, motion compensation is used to reduce temporal correlation. Motion-compensated residuals are encoded with transforms. In this paper, we develop transforms for motion-compensated residuals based on prediction inaccuracy modeling. Specifically, we observe that motion-compensation is very effective in smooth regions and still regions. In regions where strong motions occur,...
Most of the world's digital data is currently encoded in a sequential form, and compression methods for sequences have been studied extensively. However, there are many types of non-sequential data for which good compression techniques are still largely unexplored. This paper contributes insights and concrete techniques for compressing various kinds of non-sequential data via arithmetic coding, and...
A new video compression scheme for High Dynamic Range (HDR) contents is presented. It is assumed that both Standard Dynamic Range (SDR) and HDR devices coexist in the ecosystem, and the scheme is constructed to ensure backward compatibility such that a single video stream carries both the original HDR video and an automatically generated SDR version of this video without noticeable overhead relatively...
We examine lossless data compression from an average delay perspective. An encoder receives input symbols one per unit time from an i.i.d. source and submits binary codewords to a FIFO buffer that transmits bits at a fixed rate to a receiver/decoder. Each input symbol at the encoder is viewed as a status update by the source and the system performance is characterized by the status update age, defined...
In comparison with soft-decision quantization (SDQ), deadzone hard-decision quantization (HDQ) is well-suited for parallel processing, but suffering from non-negligible rate distortion (RD) performance loss. By fully simulating the behavior of SDQ, this paper proposes an adaptive deadzone offset model to improve traditional HDQ. Coefficient-wise offset model is elaborately design by offline analysis,...
The problem of function computation arises in in many practical scenarios, such as query computation in distributed databases. In such scenarios, it is often possible to exploit the structure of the function to reduce the amount of information that needs to be exchanged in order to compute it. In a so-called a collocated network, information is exchanged as users take turns sending messages to a sink,...
This paper presents a low-complexity yet effective method for encoding High Dynamic Range data into two distinct Low Dynamic Range images to be subsequently lossy or losslessly compressed using any LDR image and video codec. The method and principles described herein are applicable to both still HDR images and sequences used for HDR-video creation. The peculiar features of the method allow LDR image...
Complex software appliances typically consist of multiple software processes running concurrently to exploit the available computational resources in the hardware. However, the computational complexity of these software processes is often variable and the processes can interfere with each other. This can be an issue for real-time applications with a fixed deadline like low delay video encoding. In...
Motivated by the correlation channel modeling problem in practical applications, such as distributed video coding, we study the binary source coding of a uniform source with side information, under asymmetric correlation channel assumptions. First, we consider the case where side information is available to both the encoder and decoder, and give an analytical formula for the rate-distortion bound...
The challenge to H.265/HEVC multiview video coding (MVC) is its extremely high computational complexity. This paper presents the development and implementation of a scalable massively parallel fast search algorithm to significantly reduce the computational cost of motion and disparity estimation over the current best available GPU full block matching and sub optimal CPU fast search algorithms by a...
This paper proposes a novel compressed sensing (CS) framework that exploits (i) the sparsity of the samples in some representation domain, and (ii) the governing structure of the samples, with a focus on temperature monitoring using Wireless Sensor Networks (WSN). WSN's have been used for temperature monitoring for automation and surveillance. Despite the benefits, WSN's have their own limitations...
In this paper, we propose a novel massively parallel motion estimation for HEVC using an efficient yet flexible predicate algorithm, ScalingFast that exploits inter-pixel similarities. When evaluated over four video test video sequences with changing resolution, the proposed algorithm outperforms the anchor algorithm by factor of up to 4.6, with little to no loss in rate-distortion (RD) performance.
We introduce a compression technique for small polygons. The main application is to embed compressed polygons in emergency alert messages that have strict length restrictions, as in the case of Wireless Emergency Alert messages. We transform polygon coordinates to sets of integers and are able to compress them to between 10.4% and 25.6% of original length reducing original polygon lengths from 43-331...
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