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IEEE International Conference on image Processing (ICIP 2007)

作者： Wang, Zhou Li, Qiang Shang, Xinli Univ Texas Arlington Dept Elect Engn Arlington TX 76019 USA Microsoft Corp Redmond WA 98052 USA

ISBN: (纸本)9781424414369

perceptual image coding algorithms typically impose perceptual modeling in a preprocessing stage. A perceptual normalization model is often used to transform the original image signal into a perceptually uniform space, in which all the transform coefficients have equal perceptual importance. Standard coding schemes are then applied uniformly to all coefficients. Here we use a different approach, in which we iteratively reallocates the available bits over the image space based on a maximum of minimal structural similarity criterion. We demonstrate the proposed method by incorporating it with the bitplane coding scheme in the set partitioning in hierarchical trees algorithm.

关键词： perceptual image coding image quality assessment structural similarity (SSIM) bitplane coding set partitioning in hierarchical trees (SPIHT)

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Application of perceptual image coding and the neural network method in predicting the optimum Asphalt binder content of open-graded friction course mixtures

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ROAD MATERIALS AND PAVEMENT DESIGN 2017年第1期18卷 38-63页

作者： de Pernia, Yolibeth Mejias Gunaratne, Manjriker Univ S Florida Dept Civil & Environm Engn Tampa FL 33620 USA

Florida Department of Transportation (FDOT) designs open-graded friction course (OGFC) mixtures using a pie plate visual draindown method (FM 5-588). In this method, the optimum asphalt binder content (OBC) is determined based on visual assessment of the superficial asphalt binder draindown (SABD) distribution of three OGFC samples placed in pie plates with pre-determined asphalt binder contents (AC). In order to eliminate the human subjectivity involved in the current visual method, an automated method for quantifying the OBC of OGFC mixtures is developed using digital images of the pie plates and concepts of perceptual image coding and neural networks. Phase I involved the FM-5-588-based OBC testing of OGFC mixture designs consisting of a large set of samples prepared from a variety of granitic and oolitic limestone aggregate sources used by FDOT. Then the digital images of the pie plates containing samples of the above mixtures were acquired using an imaging setup customised by FDOT. The correlation between relevant digital imaging parameters and the corresponding AC was investigated initially using conventional regression analysis. Phase II involved the development of a perceptual image model using human perception metrics considered to be used in the OBC estimation. A General Regression Neural Network (GRNN) was used to uncover the nonlinear correlation between the selected parameters of pie plate images, the corresponding ACs and the visually estimated OBC. GRNN was found to be the most viable method to deal with the multi-dimensional nature of the input test data set originating from each individual OGFC sample that contains AC and imaging parameter information from a set of three pie plates. GRNN was trained by a major part of the database completed in Phase I. Finally, the prediction results from an independent part of the above database demonstrated that the GRNN model provides satisfactory estimations of OBC.

关键词： pavement optimum asphalt binder image processing human vision system pie plate visual method perceptual image coding

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JPEG-BASED perceptual image coding WITH BLOCK-BASED image QUALITY METRIC

JPEG-BASED PERCEPTUAL IMAGE CODING WITH BLOCK-BASED IMAGE QU...

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19th IEEE International Conference on image Processing (ICIP)

作者： Jin, Lina Egiazarian, Karen Kuo, C. -C. Jay Tampere Univ Technol Dept Signal Proc FIN-33101 Tampere Finland Univ Southern Calif Ming Hsieh Dept Elect Engn Los Angeles CA USA

ISBN: (纸本)9781467325332;9781467325349

A JPEG-based perceptual image coder is proposed in this work, where a block-based image quality metric is used to optimize the rate-quality (RQ) performance. Under this framework, the quality of each image block is measured using a local quality metric while the overall image quality is evaluated by summing up all local quality metrics. A rate-quality optimization (RQO) problem is formulated in each macroblock of size 16x16 based on its associated empirical RQ curve. Then, to achieve the best perceptual image quality under a given bit budget constraint, the set of optimal quantization parameters (QPs) for image blocks is solved using the Lagrangian approach. It is demonstrated that the proposed perceptual image codec offers a significant improvement over the JPEG baseline in both subjective and objective evaluations.

关键词： perceptual image coding image quality metric JPEG rate-quality optimization

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perceptual dithering for octave subband image coding

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JOURNAL OF VISUAL COMMUNICATION AND image REPRESENTATION 2004年第2期15卷 163-184页

作者： Wang, CN Liu, CM Chiang, TH NCTU Dept & Inst Comp Sci & Informat Engn Hsinchu 30050 Taiwan

Octave subband coding has been used as an efficient image coding approach for various well-known standards such as MPEG-4 and JPEG-2000. Although the sub-images in the octave subband representation have low statistical correlation, the visual similarity among the sub-images indicates that there exists some unexploited perceptual redundancy between sibling bands in addition to the parent-child redundancy. In this paper, we show that the original image can be perceptually dithered to form a visually equivalent image with increased interband correlation that can be used to achieve more compression. To remove the redundancy among the sibling subbands of an image, we provide a novel perceptual dithering approach that is based on entropy reduction technique with perceptual model. The theoretical basis for the entropy reduction is proven by a theorem for Gaussian distributed signals. The use of our dithering technique is demonstrated for an MPEG-4 compliant encoder with improved coding efficiency using MPEG-4 Visual Texture coding (VTC) based on zerotree entropy coding. Our results show that there exists a perceptual interband redundancy even though the original interband correlation is small. For a perceptually transparent image quality, our approach can achieve bit savings over MPEG-4 VTC by 11-30%, while maintaining compatibility with the MPEG-4 standards. (C) 2003 Elsevier Inc. All rights reserved.

关键词： image coding perceptual image coding perceptual dithering perceptual dithering coding perceptual correlation interband correlation wavelet transform octave decomposition octave subband coding MPEG-4 visual texture coding (VTC)

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image coding by perceptual pruning with a cortical snapshot indistinguishability criterion 3

Image coding by perceptual pruning with a cortical snapshot ...

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Conference on Human Vision & Electronic Imaging

作者： Horowitz, MJ Neuhoff, DL Univ Michigan Dept EECS Ann Arbor MI 48109 USA

ISBN: (纸本)081942739X

We introduce an image coding algorithm in which perceptual pruning is used to select the most perceptually relevant image components. The algorithm uses a new maximum likelihood based image indistinguishability criterion that derives from a cortical snapshot, which is a model of the response of striate cortical simple cells to the image at a given point of fixation. The criterion must be satisfied at all points of fixation. We demonstrate that this method selects image components in a better way than matching pursuit and show image coding results of high subjective quality at low encoding rates.

关键词： perceptual image coding snapshot similarity measure maximum likelihood indistinguishability criterion matching pursuit

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SAR image compression with the Gabor transform

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IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 1999年第1期37卷 574-588页

作者： Baxter, RA MIT Lincoln Lab Lexington MA 02173 USA

A compression system based on the Gabor transform is applied to detected synthetic aperture radar (SAR) imagery. The Gabor transform is a combined spatial-spectral transform that provides local spatial-frequency analyses in overlapping neighborhoods of the image. Gabor coefficients are efficiently computed using the fast Fourier transform (FFT), and a technique for visualizing the coefficients is demonstrated. Theoretical and practical constraints imposed by the Gabor transform are discussed. The compression system includes bit allocation, quantization, and lossless encoding and decoding stages. Bit allocation tradeoffs are discussed and related to perceptual image quality as well as computational measures of image fidelity. Adaptive scalar, vector, and trellis-coded quantizers are compared. Multifrequency codebooks are designed using ten training images derived from data collected at different aspect angles. Subjective image quality assessment experiments indicate that the Gabor transform/trellis-coded quantizer compression system performs significantly better than adaptive scalar and vector quantizers and JPEG on these SAR images.

关键词： Gabor transform orientation selectivity perceptual image coding synthetic aperture radar (SAR) SAR image coding SAR image compression

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image vector quantization with variable dimension blocks and edge preserving cost function

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SIGNAL PROCESSING 2003年第8期83卷 1823-1826页

作者： Selvi, SS Makur, A MS Ramaiah Inst Technol Bangalore Karnataka India Nanyang Technol Univ Singapore 2263 Singapore

This paper proposes a vector quantization scheme that uses variable vector dimensions and improves the perceived quality of the reconstructed images by using an edge based cost function. The cost function used for encoding is modified to take into account the number of edge pixels in a particular encoding block. For a better subjective quality, the product of the fraction of the edge pixels and the fraction of the non-edge pixels should be minimized. This is included in the additive cost function of VQ and minimized as an unconstrained problem. This edge based VQ technique reduces edge artifacts like jagging, ringing and also VQ distortions that happen near object contours, thus improving the overall subjective quality of the reconstructed image. (C) 2003 Elsevier Science B.V. All rights reserved.

关键词： vector quantization perceptual image coding edge based coding

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image coding VIA perceptualLY INSPIRED GRAPH LEARNING 30

IMAGE CODING VIA PERCEPTUALLY INSPIRED GRAPH LEARNING

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30th IEEE International Conference on image Processing (ICIP)

作者： Fernandez-Menduina, Samuel Pavez, Eduardo Ortega, Antonio Univ Southern Calif Los Angeles CA 90007 USA

ISBN: (纸本)9781728198354

Most codec designs rely on the mean squared error (MSE) as a fidelity metric in rate-distortion optimization, which allows to choose the optimal parameters in the transform domain but may fail to reflect perceptual quality. Alternative distortion metrics, such as the structural similarity index (SSIM), can be computed only pixel-wise, so they cannot be used directly for transform-domain bit allocation. Recently, the irregularity-aware graph Fourier transform (IAGFT) emerged as a means to include pixel-wise perceptual information in the transform design. This paper extends this idea by also learning a graph (and corresponding transform) for sets of blocks that share similar perceptual characteristics and are observed to differ statistically, leading to different learned graphs. We demonstrate the effectiveness of our method with both SSIM- and saliency-based criteria. We also propose a framework to derive separable transforms, including separable IAGFTs. An empirical evaluation based on the 5th CLIC dataset shows that our approach achieves improvements in terms of MS-SSIM with respect to existing methods.

关键词： Transform coding perceptual image coding image compression graph learning transform learning

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An HVS-based wavelet image coder

An HVS-based wavelet image coder

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8th IASTED International Conference on Signal and image Processing

作者： Guo, Linfeng Meng, Yan BrainMedica LLC New York NY 10016 USA Stevens Inst Technol Dept Elect & Comp Engn Hoboken NJ 07030 USA

ISBN: (纸本)9780889865839

An HVS-based wavelet image coder has been proposed in this paper. This coder exploits a couple of important human visual properties, including contrast sensitivity, luminance adaptation, and contrast masking. As the rudiment of the proposed scheme, the proper evaluation of local background luminance and contrast in wavelet domain is investigated within the dyadic wavelet transform framework. Furthermore, the mechanisms of several contrast masking effects, e.g., self-masking, neighbor masking, and cross-band masking are studied and incorporated into the coding scheme through an adaptive quantization scheme. Meanwhile, the coefficient dependent adaptive step sizes of the quantization can be lossless restored during the decoding without any overhead of side information.

关键词： human visual system perceptual image coding wavelet transform adaptive quantization

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perceptualLY INSPIRED WEIGHTED MSE OPTIMIZATION USING IRREGULARITY-AWARE GRAPH FOURIER TRANSFORM

PERCEPTUALLY INSPIRED WEIGHTED MSE OPTIMIZATION USING IRREGU...

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IEEE International Conference on image Processing (ICIP)

作者： Lu, Keng-Shih Ortega, Antonio Mukherjee, Debargha Chen, Yue Univ Southern Calif Los Angeles CA 90007 USA Google LLC Mountain View CA USA

ISBN: (纸本)9781728163956

In image and video coding applications, distortion has been traditionally measured using mean square error (MSE), which suggests the use of orthogonal transforms, such as the discrete cosine transform (DCT). perceptual metrics such as Structural Similarity (SSIM) are typically used after encoding, but not tied to the encoding process. In this paper, we consider an alternative framework where the goal is to optimize a weighted MSE metric, where different weights can be assigned to each pixel so as to reflect their relative importance in terms of perceptual image quality. For this purpose, we propose a novel transform coding scheme based on irregularity-aware graph Fourier transform (IAGFT), where the induced IAGFT is orthogonal, but the orthogonality is defined with respect to an inner product corresponding to the weighted MSE. We propose to use weights derived from local variances of the input image, such that the weighted MSE aligns with SSIM. In this way, the associated IAGFT can achieve a coding efficiency improvement in SSIM with respect to conventional transform coding based on DCT. Our experimental results show a compression gain in terms of multi-scale SSIM on test images.

关键词： Irregularity-aware graph Fourier transform perceptual image coding graph signal processing image compression

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