nils-herrmann/clean_scirepeval huggingface dataset:
Codec-Independent Scalable Distributed Video Coding

In this paper, we introduce novel schemes for scalable distributed video coding (DVC), dealing with temporal, spatial and quality scalabilities. More specifically, conventional coding is used to obtain a base layer. DVC is then applied to generate enhancement layers. The side information is generated either temporally by motion compensated interpolation, or spatially by a spatial bi-cubic interpolation. Note that this scalable DVC approach is independent from the codec used to encode or decode the base layer. Simulation results show that most of the proposed schemes outperform non-scalable DVC, in addition to enabling the scalability features.
H.264/AVC video scrambling for privacy protection

In this paper, we address the problem of privacy in video surveillance systems. More specifically, we consider the case of H.264/AVC which is the state-of-the-art in video coding. We assume that regions of interest (ROI), containing privacy-sensitive information, have been identified. The content of these regions are then concealed using scrambling. More specifically, we introduce two region-based scrambling techniques. The first one pseudo-randomly flips the sign of transform coefficients during encoding. The second one is performing a pseudo-random permutation of transform coefficients in a block. The flexible macroblock ordering (FMO) mechanism of H.264/AVC is exploited to discriminate between the ROI which are scrambled and the background which remains clear. Experimental results show that both techniques are able to effectively hide private information in ROI, while the scene remains comprehensible. Furthermore, the loss in coding efficiency stays small, whereas the required additional computational complexity is negligible.
Functional connectivity from EEG signals during perceiving pleasant and unpleasant odors

The olfactory sense is strongly related to memory and emotional processes. Studies on the effects of odor perception from brain activity have been conducted by using different neuro-imaging techniques. In this paper, we analyse electroencephalography (EEG) of 23 subjects during perceiving pleasant and unpleasant odor stimuli. We describe the construction of brain functional connectivity networks measured by most commonly used models. We discuss the network-based features of functional connectivity, and design classifiers by applying different functional connectivity network features. Finally, we show that pleasant and unpleasant emotions from olfactory perceptions can be better classified if we see the brain as a nonlinear small-world network. By extracting appropriate features from functional connectivity networks, we manage to classify pleasant and unpleasant olfactory perceptions with an average Kappa value of 0.11 ± 0.17, which is significantly non-random.
Using face morphing to protect privacy

The widespread use of digital video surveillance systems has also increased the concerns for violation of privacy rights. Since video surveillance systems are invasive, it is a challenge to find an acceptable balance between privacy of the public under surveillance and the functionalities of the systems. Tools for protection of visual privacy available today lack either all or some of the important properties such as security of protected visual data, reversibility (ability to undo privacy protection), simplicity, and independence from the video encoding used. To overcome these shortcomings, in this paper, we propose a morphing-based privacy protection method and focus on its robustness, reversibility, and security properties. We morph faces from a standard FERET dataset and run face detection and recognition algorithms on the resulted images to demonstrate that morphed faces retain the likeness of a face, while making them unrecognizable, which ensures the protection of privacy. Our experiments also demonstrate the influence of morphing strength on robustness and security. We also show how to determine the right parameters of the method.
JPEG2000 image coding system theory and applications

JPEG2000, the new standard for still image coding, provides a new framework and an integrated toolbox to better address increasing needs for compression. It offers a wide range of functionalities such as lossless and lossy coding, embedded lossy to lossless coding, progression by resolution and quality, high compression efficiency, error resilience and region-of-interest (ROI) coding. Comparative results have shown that JPEG2000 is indeed superior to established image compression standards. Overall, the JPEG2000 standard offers the richest set of features in a very efficient way and within a unified algorithm. The price of this is its additional complexity, but this should not be perceived as a disadvantage, as the technology evolves rapidly
Moving object detection between multiple and color images

There are several publications dedicated to the description and analysis of change detection between two gray-value images. This paper introduces new methods to detect moving objects between multiple images and to detect changes between color images or any type of multispectral images. We are not aware of methods giving the possibility of detecting color changes and changes between multiple frames. All the proposed change detectors are based on the Gramian determinant, which provides low computational cost and is easy to implement. These features are very important due to the additional complexity of change detection between multiple as well as color images.
Dynamic video coding-an overview

In this paper, we present an overview of the dynamic coding approach, together with recent developments carried out in this framework. Dynamic coding is a general approach to the problem of visual data representation in the context of multimedia. This approach consists of a dynamic combination of multiple representation models and segmentation strategies. Given an application, these two degrees of freedom are assembled so as to yield a specific profile which meets the specifications dictated by the application. The data is represented as the union of data segments, each described within a locally appropriate representation model. In order to illustrate this approach, a video compression system, based on the principles of dynamic coding, is proposed in the context of video-telephone/conference applications. This algorithm has been submitted to the MPEG-4 committee as a proposal for the first round of tests in November 1995. Recent developments have been added: in particular, a procedure enabling the generation of an object-oriented scalable bitstream is presented here. In order to reduce the blocking artifacts which are noticeable at high compression ratios, a post-processing technique is proposed.
Towards optimal distortion-based visual privacy filters

The widespread usage of digital video surveillance systems has increased the concerns for privacy violation. Since video surveillance systems are invasive, it is a challenge to find an acceptable balance between privacy of the public under surveillance and security related features of the systems. Many privacy protection tools have been proposed for preserving privacy, ranging from such simple methods like blurring or pixelization to more advanced like scrambling and geometrical transform based filters. However, for a given filter implemented in a practical video surveillance system, it is necessary to know the strength with which the filter should be applied to protect privacy reliably. Assuming an automated surveillance system, this paper objectively investigates several privacy protection filters with varying strength degrees and determines their optimal strength values to achieve privacy protection. To this end, five privacy filters were applied to images from FERET dataset and the performance of three recognition algorithms was evaluated. The results show that different privacy protection filters influence the accuracy of different versions of face recognition differently and this influence depends both on the robustness of the recognition and the type of distortion filter.
Audio-visual synchronization recovery in multimedia content

This paper proposes a method recovering audio-visual synchronization of multimedia content. It exploits the correlation between the acoustic and the visual signals in order to estimate the audio-visual drift existing in the content. By shifting the audio signal relative to the visual signal, the estimation of the drift is obtained by searching for the shift producing the maximal audio-visual correlation. We consider two correlation measures, namely, mutual information and canonical correlation, and compare their performance. Experimental results demonstrate that the method using the canonical correlation is effective in recovering the audio-visual synchronization for both speech and non-speech sequences.
Scrambling for Video Surveillance with Privacy

In this paper, we address the problem of scrambling regions of interest in a video sequence for the purpose of preserving privacy in video surveillance. We propose an efficient solution based on transform-domain scrambling. More specifically, the sign of selected transform coefficients is pseudo-randomly flipped during encoding. We address more specifically the two cases of MPEG-4 and Motion JPEG 2000. Simulation results show that the technique can be successfully applied to conceal information in regions of interest in the scene while providing with a good level of security. Furthermore, the scrambling is flexible and allows adjusting the amount of distortion introduced. Finally, this is achieved with a small impact on coding performance and negligible computational complexity increase.
Towards Generic Detection of Unusual Events in Video Surveillance

In this paper, we consider the challenging problem of unusual event detection in video surveillance systems. The proposed approach makes a step toward generic and automatic detection of unusual events in terms of velocity and acceleration. At first, the moving objects in the scene are detected and tracked. A better representation of moving objects trajectories is then achieved by means of appropriate pre-processing techniques. A supervised Support Vector Machine method is then used to train the system with one or more typical sequences, and the resulting model is then used for testing the proposed method with other typical sequences (different scenes and scenarios). Experimental results are shown to be promising. The presented approach is capable of determining similar unusual events as in the training sequences.
Subject-Independent Odor Pleasantness Classification Using Brain and Peripheral Signals

Enhanced sensation of reality from multimedia contents can be achieved by creating realistic multimedia environments, using visual, auditory, and olfactory information. Although the affective information from video and audio has been extensively studied, the olfactory sense has received less attention. A way to assess human experience from audio, video or odors, is by investigating physiological signals. In this study, 23 subjects experienced pleasant, unpleasant, and neutral odors while their electroencephalogram (EEG), and electrocardiogram (ECG) were recorded. Two independent three-class classifiers were trained and tested, using EEG or ECG features. The results reveal a significant increase in the classification performance when EEG features were used (Cohen's kappa k = 0.44 ± 0.14; p <; 0.001). The results also indicate that it is possible to automatically classify the perception of unpleasant odors using EEG signals, but the classification performance decreases significantly when classifying between pleasant and neutral odors. Among the EEG features, the Wasserstein distance metric estimated between trial and baseline power achieved the highest classification performance. Features from ECG signals did not result in a significantly non-random performance.
An analytical study of JPEG 2000 functionalities

JPEG 2000, the new ISO/ITU-T standard for still image coding, is about to be finished. Other new standards have been recently introduced, namely JPEG-LS and MPEG-4 VTC. This paper compares the set of features offered by JPEG 2000, and how well they are fulfilled, versus JPEG-LS and MPEG-4 VTC, as well as the older but widely used JPEG and the PNG. The study concentrates on the set of supported features, although lossless and lossy progressive compression efficiency results are also reported. Each standard, and the principles of the algorithms behind them, are also described. As the results show, JPEG 2000 supports the widest set of features among the evaluated standards, while providing superior rate-distortion performance.
Image transmorphing with JPEG

Picture-related applications are extremely popular because pictures present attractive and vivid information. Nowadays, people record everyday life, communicate with each other, and enjoy entertainment using various interesting imaging applications. In many cases, processed images need to be recovered to their original versions. However, most approaches require storage or transmission of both original and processed images separately, which result in increased bandwidth and storage resources to be used. In contrast, in this paper, we present a JPEG transmorphing algorithm, which converts an image to its processed version while preserving sufficient information about the original image in the processed image. It does this by inserting partial information about the original image in the application markers of the processed JPEG image file, so that the original image can be later recovered. Experiments are conducted and results show that the proposed method offers a number of attractive features and a good performance in many applications.
Scrambling for Privacy Protection in Video Surveillance Systems

In this paper, we address the problem of privacy protection in video surveillance. We introduce two efficient approaches to conceal regions of interest (ROIs) based on transform-domain or codestream-domain scrambling. In the first technique, the sign of selected transform coefficients is pseudorandomly flipped during encoding. In the second method, some bits of the codestream are pseudorandomly inverted. We address more specifically the cases of MPEG-4 as it is today the prevailing standard in video surveillance equipment. Simulations show that both techniques successfully hide private data in ROIs while the scene remains comprehensible. Additionally, the amount of noise introduced by the scrambling process can be adjusted. Finally, the impact on coding efficiency performance is small, and the required computational complexity is negligible.
Comparison of 3D portable display restitution techniques based on stereo and motion parallax

Currently, the large majority of 3D display solutions rely on binocular perception phenomena. Furthermore, while 3D display technologies are already widely available for cinema and home or corporate use, only a few portable devices currently feature 3D display capabilities. In this paper, we study the alternative methods for restitution of 3D images on displays of commercially available portable devices and analyse their respective performance. This particularly includes the restitution method which uses multiscopic image data-set and which relies on motion parallax as an additional depth cue. The goal of this paper is to compare three different commercially available 3D display techniques, the auto-stereoscopic and anaglyph method which provide binocular depth cues and a method based on motion parallax. The subsequently conducted subjective quality tests show that the motion parallax based approach to present 3D images on consumer portable screen is an equivalent and quite competitive way in comparison to the above mentioned stereopsis based methods.
Performance analysis of multicarrier frequency-hopping (MC-FH) code division multiple-access systems: uncoded and coded schemes

We consider the multiuser capacity of a multicarrier frequency-hopping (MC-FH) CDMA system as first introduced by Lance and Kaleh (1997). We propose to use a practical low-rate convolutional error correcting code in this system which does not require any extra bandwidth further than needed by the frequency-hopping spread-spectrum modulation. We provide a multiuser performance analysis of the system for both uncoded and coded schemes in AWGN and fading channels based on a Gaussian distribution assumption for the multiuser interference term. We also derive the exact bit error rate (BER) of the system in an AWGN channel. Our numerical results first indicate that the coded scheme significantly outperforms the uncoded scheme in both AWGN and fading channels. Moreover, it shows that the Gaussian analysis in some cases does not predict accurately the number of users supported by the system.
Objective evaluation of the perceptual quality of 3D watermarking

In this paper an objective metric to measure the perceptual quality of watermarked 3D meshes is presented. The metric, which is based on a black-box approach, relies on the measurement of the roughness of 3D meshes before and after the insertion of the watermark. To calibrate the metric and to validate it, a set of psychovisual experiments has been carried out. Due to the lack of prior work in this field, a new methodology for the subjective evaluation of the quality of watermarked 3D objects is introduced. The validity of the proposed metric has been tested against a number of different 3D watermarking algorithms, showing an excellent match with the subjective evaluation of the quality stemming from the psychovisual experiments.
Towards second generation watermarking schemes

The digital watermarking schemes of today use pixels (samples in the case of audio), frequency or other transform coefficients to embed the information. The drawback of such schemes is that the watermark is not embedded in the perceptually significant portions of the data. We refer to such techniques as first generation watermarking schemes. In this paper we introduce the concept of second generation watermarking schemes which, unlike first generation watermarking schemes, employ the notion of data features. We propose a scheme based on point features in images using a scale interaction technique based on 2D continuous wavelets. The features are used to compute a Voronoi partition of the image. The watermark is embedded in each segment using spread spectrum watermarking. In the recovery process the same features are detected, and again used to partition the image. Then the watermark is extracted from each segment separately.
Motion parallax based restitution of 3D images on legacy consumer mobile devices

While 3D display technologies are already widely available for cinema and home or corporate use, only a few portable devices currently feature 3D display capabilities. Moreover, the large majority of 3D display solutions rely on binocular perception. In this paper, we study the alternative methods for restitution of 3D images on conventional 2D displays and analyze their respective performance. This particularly includes the extension of wiggle stereoscopy for portable devices which relies on motion parallax as an additional depth cue. The goal of this paper is to compare two different 3D display techniques, the anaglyph method which provides binocular depth cues and a method based on motion parallax, and to show that the motion parallax based approach to present 3D images on consumer 2D portable screen is an equivalent way in comparison to the above mentioned and well-known anaglyph method. The subsequently conducted subjective quality tests show that viewers even prefer wiggle over anaglyph stereoscopy mainly due to a better color reproduction and a comparable depth perception.
MPEG-7 camera

An MPEG-7 camera extends the capabilities of conventional cameras by analyzing its scene in order to generate a content-based description according to the recently approved MPEG-7 standard. This gives to the camera a large variety of current and potential applications, such as surveillance, augmented reality, and virtual display. This paper provides an overview of what is meant by an MPEG-7 camera, discusses the above mentioned applications, and provides an implementation example of such a camera using existing hardware products.
ICtCp Versus Y'CbCr: Evaluation of ICtCp Color Space and an Adaptive Reshaper for HDR and WCG

New emerging technologies in the field of multimedia, such as high dynamic range (HDR) and wide color gamut (WCG), challenge the performance of existing image and video data processing algorithms, especially in terms of visual data compression and its faithful representation. HDR and WCG offer the technological capabilities to capture and represent a scene with an extended amount of details in both luminance and chrominance, respectively. This article presents and evaluates possible solutions to cope with such an extensive amount of data while delivering a faithful representation of visual information. More particularly, two approaches proposing novel color space, a constant intensity color difference signal representation called ICtCp and a novel compression optimization algorithm called the reshaper, are described and subjectively evaluated. The results of the conducted experiments show competitive performance of the two proposed approaches, ICtCp and reshaper, allowing a 10% bit rate reduction while preserving the perceived quality.
Comparison and Evaluation of Light Field Image Coding Approaches

The recent advances in light field imaging, supported among others by the introduction of commercially available cameras, e.g., Lytro or Raytrix, are changing the ways in which visual content is captured and processed. Efficient storage and delivery systems for light field images must rely on compression algorithms. Several methods to compress light field images have been proposed recently. However, in-depth evaluations of compression algorithms have rarely been reported. This paper aims at the evaluation of perceived visual quality of light field images and at comparing the performance of a few state-of-the-art algorithms for light field image compression. First, a processing chain for light field image compression and decompression is defined for two typical use cases, professional and consumer. Then, five light field compression algorithms are compared by means of a set of objective and subjective quality assessments. An interactive methodology recently introduced by authors, as well as a passive methodology is used to perform these evaluations. The results provide a useful benchmark for future development of compression solutions for light field images.
Watermarked 3-D Mesh Quality Assessment

This paper addresses the problem of assessing distortions produced by watermarking 3D meshes. In particular, a new methodology for subjective evaluation of the quality of 3D objects is proposed and implemented. Two objective metrics derived from measures of surface roughness are then proposed and their efficiency to predict the perceptual impact of 3D watermarking is assessed and compared with the state of the art. Results obtained show good correlations between the proposed objective metrics and subjective assessments by human observers
Efficient video coding in H.264/AVC by using audio-visual information

This paper proposes an efficient video coding method which utilizes audio-visual information, based on the observation that sound-emitting regions in a video sequence attract observer's attention. The regions responsible for the sound are identified by an audio-visual source localization algorithm. Then, the result is used for encoding different regions in the scene with different quality in such a way that a region far from the sound source is coded with a lesser quality than the sound-emitting regions. This is implemented by assigning different quantization parameter values for different regions in H.264/AVC. Experimental results demonstrate the effectiveness of the proposed approach.