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In video coding, the transform-quantization scheme has been widely used to remove perceptual redundancy. Typically, transform and quantization are carried out separately for the prediction residuals. However, since the residual blocks commonly exhibit diverse spectral characteristics, the quantization with predefined constant dead-zone under a given parameter will inevitably deteriorate the compression...
One step required several times for current video encoders is the residual coding loop, composed of the direct transformation, direct quantization, inverse quantization, and inverse transformation. These operations demand high throughput and low latency since their outputs must be processed by other steps of the coder. This paper proposes a high-throughput parallel and multiplierless hardware architecture...
Quantization issues have fundamental bearings on regulation and transient behavior of digitally controlled DC-DC converters. Further, the inherent nonlinearities of quantization may lead to nonlinear oscillations. Usually, the methods to address these oscillations are either resource-intensive, or employ techniques which degrade transient and/or steady-state performance. In this work, we evaluate...
Power theft is one of the major concerns of many developing countries including India. The state of Jammu and Kashmir is one of the worst affected states of India, having about 50% of transmission and distribution losses. The proposed work is an attempt to stop the losses by preventing the power theft, using encoding and decoding techniques of the analog signal. Encoding is done at the distribution...
Electroencephalogram (EEG) has been widely used in diagnosing brain-related diseases, brain-computer interface applications, and user authentication and identification in security systems. Large EEG databases have been built and therefore, an effective EEG compression technique is necessary to reduce data for transmitting, processing and storing. In this paper, we propose an EEG lossy compression...
Image compression is gaining good deal of attention and development nowadays. There are many uses and benefits incorporated with this application. Compressing an image will reduce its size to some amount that will enhance its storage or transmission over a network. In this paper, we proposed and compared two (Shift Coding) based techniques that we developed to gain the best compression ratios while...
Ozarow's test channel for the quadratic Gaussian (QG) multiple description (MD) problem consists of two correlated AWGN channels. It is known that simply replacing the AWGN channels by quantizers with equivalent statistical properties as the channels, will generally not lead to a rate-distortion optimal realization of the MD rate-distortion function. We have previously proposed a symmetric two-channel...
The paper presents a VLSI architecture of three dimensional discrete cosine transform (3D DCT) for video recent compression. By making use of the separability property of DCT, the 3D DCT is decomposed into 1D DCTs computed in each of the three dimensions. Each 1D DCT is carried out as an integer DCT using the butterfly structure. It is useful for reducing the computation time and also makes our structure...
High efficiency video coding (HEVC) is the latest international video compression standard that achieves double compression efficiency than the previous standard H.264/AVC. To increase the compression accuracy, HEVC employs the coding unit (CU) ranging from 8 × 8 to 64 × 64. However, the encoding complexity of HEVC increase a lot since the manifold partition sizes. A lot of works are focused on reducing...
Approximate Nearest Neighbor (ANN) search for indexing and retrieval has become very popular with the recent growth of the databases in both size and dimension. In this paper, we propose a novel method for fast approximate distance calculation among the compressed samples. Inspiring from Kohonen's self-organizing maps, we propose a structured hierarchical quantization scheme in order to compress database...
Univariate discretization approach that transforms continuous attributes into discrete elements/binary string based on discrete/binary feature extraction on a single dimensional basis have been attracting much attention in the biometric community mainly to derive biometric-based cryptographic key derivation for security purpose. However, since components of biometric feature are interdependent, univariate...
We propose a linear transceiver scheme for the symmetric two-user multiple access channel with additive white Gaussian noise and quantized feedback. The quantized feedback link is modeled as an information bottleneck subject to a rate constraint. We introduce a superposition scheme that splits the transmit power of each user between an Ozarow-like code (designed for perfect rate-limited feedback)...
In this paper, we investigate the problem of visual information encoding and decoding for face recognition. We propose a decomposition representation with vector quantization and constrained likelihood projection. The optimal solution is considered from the point of view of the best achievable classification accuracy by minimizing the probability of error under a given class of distortions. The performance...
Optimal zero-delay coding (quantization) of a finite-state Markov source is considered. Building on our earlier work and previous literature, using a stochastic control problem formulation, the existence and structure of optimal quantization policies are studied. Our main result establishes, for infinite horizon problems, the optimality of deterministic and stationary (Walrand-Varaiya type) Markov...
High Efficiency Video Coding (HEVC) is the most recent video compression standard that achieves higher encoding efficiency over earlier popular standards like MPEG-2 and H.264/AVC. By adopting a variety of coding efficiency enhancement and parallel processing tools, HEVC is in a position to provide up to 50% more bit-rate reduction over its precursor H.264/AVC. In an HEVC encoder, transforms are applied...
Polar codes have a regular-recursive structure, which can efficiently be mapped to hardware for practical applications. A good quantization scheme plays a great important role in hardware implementation. In this paper, three uniform quantizers are designed for successive cancellation (SC) decoding of polar codes based on either optimizing the equivalent channel capacity, cutoff rate or mean-squared...
Similar to previous video coding standards, transform and quantization are used in the most recent video coding standard High Efficiency Video Coding (HEVC) and a large number of transform coefficients are quantized to zeros. In order to reduce the computations involved in transform and quantization in HEVC, a prediction approach based on Gaussian model is proposed to predict zero quantized transform...
Due to the wide usage of biometrics, its security issues deserve more attention. Many of biometric protection systems require the biometric templates to be presented in a binary form. Therefore, extracting binary templates from real-valued biometric data is a key step in biometric data protection systems. In addition to meeting the security and privacy requirements, binary biometric templates allow...
It is of great value to study control systems employing sensors and actuators which are geographically separated. In this paper, we study a system with bounded noise and stabilize it under output quantized feedback. Some people have done research on full-state observable linear systems. Here we consider the general(not necessarily full-state observable) output feedback situation with system noise...
Wavelet-based coding systems commonly employ uniform scalar deadzone quantization (USDQ) together with a bitplane coding strategy to progressively refine image quality. Our previous work presents a quantization scheme that employs 2 step sizes depending on the magnitude of the coefficients. This 2-step scalar deadzone quantization (2SDQ) scheme is introduced in the framework of JPEG2000 by modifying...
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