Publications by Touradj Ebrahimi

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Distributed Video Coding (DVC) is a new paradigm for video compression based on the information theoretical results of Slepian-Wolf (SW) and Wyner-Ziv (WZ). In this work, a performance analysis of image and video coding schemes based on DVC are presented, ...

Point clouds are effective data structures for the rep- resentation of three-dimensional media and hence adopted in a wide range of practical applications. In many cases, the portrayed data is expected to be visualized by humans. After acquisition, point c ...

In recent years, new emerging immersive imaging modalities, e.g. light fields, have been receiving growing attention, becoming increasingly widespread over the years. Light fields are often captured through multi-camera arrays or plenoptic cameras, with th ...

Using DNA molecules for data storage presents a compelling solution to the ever-growing demand for efficient and sustainable data storage systems. DNA offers notable advantages in terms of storage density, longevity, and energy efficiency. This has made the development of effective coding and compression techniques for DNA-based storage a critical research area within signal processing. One particularly challenging aspect is the encoding of multimedia content, such as images, for storage in DNA. JPEG DNA, a

Photo privacy has raised a growing concern with the advancements of image analytics, face recognition, and deep learning techniques widely applied on social media. If properly deployed, these powerful techniques can in turn assist people in enhancing their ...

The Joint Photographic Experts Group (JPEG) AI learning-based image coding system is an ongoing joint standardization effort between International Organization for Standardization (ISO), International Electrotechnical Commission (IEC), and International Te ...

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.

We present an MPEG--7 compliant description of video sequences for scalable transmission and reconstruction. The proposed method is content-based and permits efficient and flexible video coding while keeping the benefits of textual descriptions in database applications. Video objects are described in terms of shape, color, texture and motion. These features are extracted automatically and are sufficient in a wide range of applications like smart video cameras and Universal Multimedia Access (UMA). Scalable

The task of extracting objects in video sequences emerges in many applications such as object-based video coding (e.g., MPEG-4) and content-based video indexing and retrieval (e.g., MPEG-7). The MPEG-4 standard provides specifications for the coding of vid ...

In recent years, light field imaging has attracted the attention of the academic and industrial communities thanks to its enhanced rendering capabilities that allow to visualise contents in a more immersive and interactive way. However, those enhanced capa ...

A brain-computer interface (BCI) is a communication system that translates brain activity into commands for a computer or other devices. In other words, a BCI allows users to act on their environment by using only brain activity, without using peripheral nerves and muscles. The major goal of BCI research is to develop systems that allow disabled users to communicate with other persons, to control artificial limbs, or to control their environment. An alternative application area for brain-computer interfaces

The visual attention mechanism plays a key role in the human perception system and it has a significant impact on our assessment of perceived video quality. In spite of receiving less attention from the viewers, unattended stimuli can still contribute to t ...

The advent of new technologies in cinema, theatre and virtual reality together with increasing demands for new content, are pushing the boundaries of filmmaking and storytelling to the limits of our imaginations. The potential for 3D film to blur the line ...

This paper presents a framework for joint adaptation of an audiovisual content and its metadata. The presentation of the audiovisual content and its metadata are balanced to fit the given screen size in a way that maximizes user experience in browsing the desired content. The adaptation process is modeled as an optimization problem of the total value of the content provided to the user. The total content value is maximized by jointly controlling the balance between video and metadata presentation, the adapt

This chapter introduces the field of Mixed Reality that merges the real and virtual worlds seamlessly. To develop a Mixed Reality system, two fundamental problems should be addressed: tracking and user interface. Tracking in Mixed Reality is defined as the task of estimating the user's viewing pose. The goal of tracking is to achieve an accurate registration between real and virtual objects. In order to allow the user to interact e±ciently with the Mixed Reality scene, interaction techniques should be desig

We present an encoding framework which exploits semantics for video content delivery. The video content is organized based on the idea of main content message. In the work reported in this paper, the main content message is extracted from the video data th ...

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, t ...

In this paper, we propose a technique for image replica detection. By replica, we mean equivalent versions of a given reference image, e.g. after it has undergone operations such as compression, filtering or resizing. Applications of this technique include discovery of copyright infringement or detection of illicit content. The technique is based on the extraction of multiple features from an image, namely texture, color, and spatial distribution of colors. Similar features are then grouped into groups and

In recent years, learning-based image compression has demonstrated similar or superior performance when com- pared to conventional approaches in terms of compression efficiency and visual quality. Typically, learning-based image compression takes advantage of autoencoders, which are architectures consisting of two main parts: a multi-layer neural network encoder and its dual decoder. The encoder maps the input image represented in the pixel domain to a compact representation, also known as latent space. Con

Crowdsourcing is a popular tool for conducting subjective evaluations in uncontrolled environments and at low cost. In this paper, a crowdsourcing study is conducted to investigate the impact of High Dynamic Range (HDR) imaging on subjective face recogniti ...

Touradj Ebrahimi

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Error-resilient Scalable Compression based on Distributed Video Coding

Towards a multiscale point cloud structural similarity metric

Towards learning-based denoising of light fields

On the performance of learning-based image compression as source coding for JPEG DNA

Context-Dependent Privacy-Aware Photo Sharing based on Machine Learning

The JPEG AI Standard: Providing Efficient Human and Machine Visual Data Consumption

Objective Evaluation of the Perceptual Quality of 3D Watermarking

MPEG-7 Description for Scalable Video Reconstruction

On Evaluating Video Object Segmentation Quality: A Perceptually Driven Objective Metric

A graph learning approach for light field image compression

Recent Advances in Brain-Computer Interfaces

Balancing Attended and Global Stimuli in Perceived Video Quality Assessment

Exposure effect on experience and visual perception in stereoscopic visual presentations

Balancing Video and Metadata Adaptation for Universal Multimedia Access

Tracking and User Interface for Mixed Reality

Semantic Video Analysis for Adaptive Content Delivery and Automatic Description

Subject-Independent Odor Pleasantness Classification Using Brain and Peripheral Signals

Image Replica Detection based on Support Vector Classifier

Towards image denoising in the latent space of learning-based compression

Impact of Tone-mapping Algorithms on Subjective and Objective Face Recognition in HDR Images