Results 1 - 10 of 1,862

Visibility of Wavelet Quantization Noise

by Andrew B. Watson, Gloria Y. Yang, Joshua A. Solomon, John Villasenor , 1996
"... The Discrete Wavelet Transform (DWT) decomposes an image into bands that vary in spatial frequency and orientation. It is widely used for image compression. Measures of the visibility of DWT quantization errors are required to achieve optimal compression. Uniform quantization of a single band of coe ..."
Abstract - Cited by 145 (1 self) - Add to MetaCart
of coefficients results in an artifact that we call DWT uniform quantization noise; it is the sum of a lattice of random amplitude basis functions of the corresponding DWT synthesis filter. We measured visual detection thresholds for samples of DWT uniform quantization noise in Y, Cb, and Cr color channels

CORRELATION PROPERTIES OF QUANTIZATION NOISE

by Peter Kabal
"... This paper examines the correlation properties of quantization noise. The quantization noise energy is subtractive if the quantizer output levels are optimized for the probability density of the input signal (pdf optimized). This paper gives a new result that shows that a quantizer (uniform or not) ..."
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This paper examines the correlation properties of quantization noise. The quantization noise energy is subtractive if the quantizer output levels are optimized for the probability density of the input signal (pdf optimized). This paper gives a new result that shows that a quantizer (uniform or not

Quantization

by Robert M. Gray, David L. Neuhoff - IEEE TRANS. INFORM. THEORY , 1998
"... The history of the theory and practice of quantization dates to 1948, although similar ideas had appeared in the literature as long ago as 1898. The fundamental role of quantization in modulation and analog-to-digital conversion was first recognized during the early development of pulsecode modula ..."
Abstract - Cited by 884 (12 self) - Add to MetaCart
modulation systems, especially in the 1948 paper of Oliver, Pierce, and Shannon. Also in 1948, Bennett published the first high-resolution analysis of quantization and an exact analysis of quantization noise for Gaussian processes, and Shannon published the beginnings of rate distortion theory, which would

EVLA Memo. 88 Quantization Noise

by A. R. Thompson, D. T. Emerson , 2005
"... In receiving systems in which the analog signal voltage is sampled and quantized to allow further processing in digital form, the difference between the analog samples and their digital representation gives rise to a component of random quantization noise. The power spectrum of the quantization nois ..."
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In receiving systems in which the analog signal voltage is sampled and quantized to allow further processing in digital form, the difference between the analog samples and their digital representation gives rise to a component of random quantization noise. The power spectrum of the quantization

The Visibility of DCT Quantization Noise

by H. A. Peterson, A. J. Ahumada, A. B. Watson - Digest of Technical Papers, Society for Information Display, Playa , 1993
"... any standard image compression techniques i apply the Discrete Cosine Transform (DCT) to the mage, then quantize the resulting transform coefficients. b For optimal compression, the DCT coefficients should e quantized as coarsely as possible, while allowing . Q minimal visible distortion in the deco ..."
Abstract - Cited by 5 (2 self) - Add to MetaCart
any standard image compression techniques i apply the Discrete Cosine Transform (DCT) to the mage, then quantize the resulting transform coefficients. b For optimal compression, the DCT coefficients should e quantized as coarsely as possible, while allowing . Q minimal visible distortion

QUANTIZATION NOISE ESTIMATION FOR LOG-PCM

by Mohamed Konaté, Peter Kabal
"... ITU-T G.711.1 is a multirate wideband extension for the wellknown ITU-T G.711 pulse code modulation of voice frequencies. The extended system is fully interoperable with the legacy narrowband one. In the case where the legacy G.711 is used to code a speech signal and G.711.1 is used to decode it, qu ..."
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, quantization noise may be audible. For this situation, the standard proposes an optional postfilter. The application of postfiltering requires an estimation of the quatization noise. In this paper we review the process of estimating this coding noise and we propose a better noise estimator. Index Terms

DCT quantization noise in compressed images

by Mark A. Robertson, Robert L. Stevenson - in Proc. Int. Conf. Image Process , 2001
"... In lossy image compression schemes utilizing the discrete cosine transform (DCT), quantization of the DCT coefficients introduces error in the image representation and a loss of signal information. At high compression ratios, this introduced error produces visually undesirable compression artifacts ..."
Abstract - Cited by 25 (0 self) - Add to MetaCart
that can dramatically lower the perceived quality of a particular image. This paper provides a spa-tial domain model of the quantization error based on a statistical noise model of the error introduced when quantizing the DCT co-efficients. The resulting theoretically derived spatial domain quan-tization

Relationship between sampling rate and quantization noise

by Pablo R. Pérez-alcázar, Andrés Santos
"... Abstract.- Few works have been done about the dependency of the quantization noise with the sampling rate for uniform quantizers. Some of these works have considered the problem from a determinis tic point of view while others study it from a stochastic one, having explained the noise behavior in so ..."
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Abstract.- Few works have been done about the dependency of the quantization noise with the sampling rate for uniform quantizers. Some of these works have considered the problem from a determinis tic point of view while others study it from a stochastic one, having explained the noise behavior

1Quantization Noise Shaping for Information Maximizing ADCs

by Arthur J. Redfern, Kun Shi
"... Abstract—ADCs sit at the interface of the analog and dig-ital worlds and fundamentally determine what information is available in the digital domain for processing. This paper shows that a configurable ADC can be designed for signals with non constant information as a function of frequency such that ..."
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such that within a fixed power budget the ADC maximizes the information in the converted signal by frequency shaping the quantization noise. Quantization noise shaping can be realized via loop filter design for a single channel delta sigma ADC and extended to common time and frequency interleaved multi channel

DAC Quantization-Noise Cancellation in an Echo-Canceling Transceiver *

by Paul Hurst, Andy Norrell
"... Copyright IEEE 2007. Personal use of this material is permitted. However, permission to use this material for any other purposes must be obtained from the IEEE by sending an email to pubs-permissions@ieee.org. Abstract — Data converters, in particular the transmit digitalto-analog converter (DAC), s ..."
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), should not limit performance in a digital-communication transceiver. Typically, the number of DAC bits is chosen to be large enough so that the effect of DAC quantization noise on the local receiver is negligibly small. As described in this paper, the DAC quantization noise can be cancelled in a echo
Results 1 - 10 of 1,862