Objective methods for assessing perceptual image quality traditionally attempted to quantify the visibility of errors (differences) between a distorted image and a reference image using a variety of known properties of the human visual system. Under the assumption that human visual perception is highly adapted for extracting structural information from a scene, we introduce an alternative complementary framework for quality assessment based on the degradation of structural information. As a specific example of this concept, we develop a structural similarity index and demonstrate its promise through a set of intuitive examples, as well as comparison to both subjective ratings and state-of-the-art objective methods on a database of images compressed with JPEG and JPEG2000. A MATLAB implementation of the proposed algorithm is available online at http://www.cns.nyu.edu//spl sim/lcv/ssim/.

/pdf/image-quality-assessment-from-error-visibility-to-structural-1rlwcqe34t.pdf

Image quality assessment: from error visibility to structural similarity

Introduction to a Transient World. Fourier Kingdom. Discrete Revolution. Time Meets Frequency. Frames. Wavelet Zoom. Wavelet Bases. Wavelet Packet and Local Cosine Bases. An Approximation Tour. Estimations are Approximations. Transform Coding. Appendix A: Mathematical Complements. Appendix B: Software Toolboxes.

http://ahvazdownload.persiangig.com/document/article/39.pdf

A wavelet tour of signal processing

We investigate conditional adversarial networks as a general-purpose solution to image-to-image translation problems. These networks not only learn the mapping from input image to output image, but also learn a loss function to train this mapping. This makes it possible to apply the same generic approach to problems that traditionally would require very different loss formulations. We demonstrate that this approach is effective at synthesizing photos from label maps, reconstructing objects from edge maps, and colorizing images, among other tasks. Moreover, since the release of the pix2pix software associated with this paper, hundreds of twitter users have posted their own artistic experiments using our system. As a community, we no longer hand-engineer our mapping functions, and this work suggests we can achieve reasonable results without handengineering our loss functions either.

/pdf/image-to-image-translation-with-conditional-adversarial-5058t24et2.pdf

Image-to-Image Translation with Conditional Adversarial Networks

We investigate conditional adversarial networks as a general-purpose solution to image-to-image translation problems. These networks not only learn the mapping from input image to output image, but also learn a loss function to train this mapping. This makes it possible to apply the same generic approach to problems that traditionally would require very different loss formulations. We demonstrate that this approach is effective at synthesizing photos from label maps, reconstructing objects from edge maps, and colorizing images, among other tasks. Indeed, since the release of the pix2pix software associated with this paper, a large number of internet users (many of them artists) have posted their own experiments with our system, further demonstrating its wide applicability and ease of adoption without the need for parameter tweaking. As a community, we no longer hand-engineer our mapping functions, and this work suggests we can achieve reasonable results without hand-engineering our loss functions either.

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

A Very Long Instruction Word (VLIW) processor and a superscalar processor can execute multiple instructions simultaneously. A VLIW processor depends on the compiler and programmer to find the parallelism in the instructions, whereas a superscaler processor determines the parallelism at runtime. This paper compares TI TMS320C6700 VLIW digital signal processor (DSP) and SimpleScalar superscalar implementations of a baseline 11.263 video encoder in C. With level two C compiler optimization, a one-way issue superscalar processor is 7.5 times faster than the VLIW DSP for the same processor clock speed. The superscalar speedup from one-way to four-way issue is 2.88:1, and from four-way to 256-way issue is 2.43:1. To reduce the execution time on the C6700, we write assembly routines for sum-of-absolute-difference, interpolation, and reconstruction, and place frequently used code and data into on-chip memory. We use TI's discrete cosine transform assembly routines. The hand optimized VLIW DSP implementation is 61/spl times/ faster than the C version compiled with level two optimization. Most of the improvement was due to the efficient placement of data and programs in memory. The hand optimized VLIW implementation is 14% faster than a 256-way superscalar implementation without hand optimizations.

VLIW DSP vs. superscalar implementation of a baseline 11.263 video encoder

We extend our previous work on Multilinear Independent Component Analysis (MICA) by introducing a Fast-MICA algorithm that demonstrates the same improvement over classical ICA as the original MICA algorithm [1] while improving the computational speed by two polynomial orders of magnitude. Apart for enabling a faster determination of the multilinear structure of image patch probability density, this new approach opens up, for the first time, the possibility of computing a novel non-stationarity index based on the relative change in mutual information. We demonstrate the performance of our Fast-MICA algorithm together with an illustration of our novel non-stationarity index.

/pdf/a-fast-multilinear-ica-algorithm-4kfzujmjt1.pdf

A fast Multilinear ICA algorithm

Virtual Reality is regaining attention due to recent advancements in hardware technology. Immersive images / videos are becoming widely adopted to carry omnidirectional visual information. However, due to the requirements for higher spatial and temporal resolution of real video data, immersive videos require significantly larger bandwidth consumption. To reduce stresses on bandwidth, foveated video compression is regaining popularity, whereby the space-variant spatial resolution of the retina is exploited. Towards advancing the progress of foveated video compression, we propose a full reference (FR) foveated image quality assessment algorithm, which we call foveated entropic differencing (FED), which employs the natural scene statistics of bandpass responses by applying differences of local entropies weighted by a foveation-based error sensitivity function. We evaluate the proposed algorithm by measuring the correlations of the predictions that FED makes against human judgements on the newly created 2D and 3D LIVE-FBT-FCVR databases for Virtual Reality (VR). The performance of the proposed algorithm yields state-of-the-art as compared with other existing full reference algorithms. Software for FED has been made available at: http://live.ece.utexas.edu/research/Quality/FED.zip

Evaluating Foveated Video Quality Using Entropic Differencing

Extensive research has been conducted relating the natural scene statistics of luminance and depth; however, very little work has been done on analyzing the statistical relationships between depth and chromatic information. In this paper, we examine and derive statistical models between disparity and both luminance and chrominance information by transforming natural images into the more perceptually relevant CIELAB color space. To demonstrate the effectiveness of these models, we further exploit them with application to Bayesian stereo algorithms. The simulation results show that incorporating the derived statistical models augments the performance of Bayesian stereo algorithms. In addition, these results also support psychophysical evidence that chromatic information can improve binocular visual processing.

/pdf/statistical-model-of-color-and-disparity-with-application-to-4lkjp3b0fr.pdf

Statistical model of color and disparity with application to Bayesian stereopsis

We propose two H.264 bit rate prediction and selection applications based on features extracted for our blind video quality assessment (VQA) algorithm, Video BLIINDS. We describe the blind VQA algorithm briefly, and we show that is correlates highly with human judgments of quality. We then demonstrate two applications: an H.264 bit rate predictor and an H.264 bit rate selector.

https://hal.archives-ouvertes.fr/hal-01207875/document

Alan C. Bovik

Papers

VLIW DSP vs. superscalar implementation of a baseline 11.263 video encoder

A fast Multilinear ICA algorithm

Evaluating Foveated Video Quality Using Entropic Differencing

Statistical model of color and disparity with application to Bayesian stereopsis

Blind Prediction of Natural Video Quality and H.264 Applications