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

In this paper, we propose a methodology for optimal image transmission over a VSNs (Visual Sensor Networks) via cross-layer optimization. Toward this goal, we control the compression ratio of a captured image and network parameters such as source rate, flow rate and routing path. In particular, since this scheme is based on distributed optimization, we can avoid energy concentration in a specific node such as CH (Cluster Head) which increases the network lifetime. In the simulation, we demonstrate the network adaptation procedure over a randomly deployed VSNs and evaluate the quality of the transmitted image using the SSIM (Structural Similarity) index.

Optimal image transmission over Visual Sensor Networks

Video live streaming is gaining prevalence among video streaming services, especially for the delivery of popular sporting events. Many objective Video Quality Assessment (VQA) models have been developed to predict the perceptual quality of videos. Appropriate databases that exemplify the distortions encountered in live streaming videos are important to designing and learning objective VQA models. Towards making progress in this direction, we built a video quality database specifically designed for live streaming VQA research. The new video database is called the Laboratory for Image and Video Engineering (LIVE) Live stream Database. The LIVE Livestream Database includes 315 videos of 45 contents impaired by 6 types of distortions. We also performed a subjective quality study using the new database, whereby more than 12,000 human opinions were gathered from 40 subjects. We demonstrate the usefulness of the new resource by performing a holistic evaluation of the performance of current state-of-the-art (SOTA) VQA models. The LIVE Livestream database is being made publicly available for these purposes at this https URL.

Assessment of Subjective and Objective Quality of Live Streaming Sports Videos

Presents a model for Raman microscopic images. The model describes the degradation of Raman signals by non-uniform illumination, by the microscopic system, and by additive signal-dependent Gaussian noise. Using this model, synthetic images were created to validate the model. Based on these synthetic images, an anisotropic diffusion filter was applied to reduce the signal-dependent Gaussian noise and at the same time not blur the objects' boundary. A Wiener filter was used to restore the blurred Raman images by the microscopic system. And, an image ratioing method was used to correct for the non-uniform illumination. After the restoration, the mean absolute error between the restored image and the true image was minimized.

Modeling and restoration of Raman microscopic images

We conducted a series of human subjective studies where we found that the visibility of flicker distortions on naturalistic videos is strongly reduced when the speed of coherent object motion is large. Based on this, we propose a model of flicker visibility on naturalistic videos. The model predicts target-related activation levels in the excitatory layer of neurons for a video using spatiotemporal backward masking. The target-related activation level is then shifted and scaled according to video quality level changes that cause flicker distortions. Finally, flicker visibility is predicted based on neural flicker adaptation processes. Results show that the predicted flicker visibility using the model correlates well with human perception of flicker distortions on naturalistic videos.

/pdf/visibility-prediction-of-flicker-distortions-on-naturalistic-1p0u5bnczd.pdf

Visibility prediction of flicker distortions on naturalistic videos

We propose two scheduling algorithms that seek to optimize the perceptual quality of scalably coded videos transmitted over slow fading wireless channels. The first scheduling algorithm is derived from a Markov Decision Process (MDP) formulation developed here. We model the dynamics of the channel as a Markov chain and reduce the problem of dynamic video scheduling to a tractable Markov decision problem over a finite state space. Based on the MDP formulation, a near-optimal scheduling policy is computed that maximizes an objective proxy of video quality, the time-average {\em Multi-Scale Structural SIMilarity} (MS-SSIM) index. Using sights token from the development of the optimal MDP-based scheduling policy, the second proposed scheduling algorithm is an online scheduling method that only requires only easily measurable knowledge of the channel dynamics, and is thus viable in practice. Simulation results show that the performance of both scheduling algorithms is close to a performance upper bound also derived in this paper.

Alan C. Bovik

Papers

Optimal image transmission over Visual Sensor Networks

Assessment of Subjective and Objective Quality of Live Streaming Sports Videos

Modeling and restoration of Raman microscopic images

Visibility prediction of flicker distortions on naturalistic videos

Near-optimal Adaptive Scheduling of Scalable Videos over Wireless Channels