Mohammed Ghanbari

University of Essex · School of Computer Science and Electronic Engineering

Temporal segmentation of video into shots is the first step in most video analysis. This is because within a shot, consecutive frames are similar to each other, leading to numerous video analyses. It is highly desired if temporal segmentation can be carried out directly on the compressed video streams. In this paper, a method is presented for time...

This paper presents a method for evaluating the quality of images altered by Gaussian blur. The method is based on the observation of bokeh mode images where the region of interest (foreground) is sharp, while the remaining parts (background) are intentionally blurred to enhance the perceptual quality of the image. The blurriness of the background...

Cooperative candidate relay sets (CRS) in opportunistic broadcast paradigms can significantly improve the performance efficiency of traditional broadcast schemes by simultaneously scheduling multiple vehicles in the data packet transmission process. Nonetheless, multiple relay synchronization may cause enormous data redundancy and high delays in da...

Background: Watermarking such as other security concepts is an ongoing challenging research issue, especially for medical images, to protect patient privacy. Medical images need to be shared and transferred between hospitals and specialists as quickly as possible for better diagnosis. Fast and simple watermarking is needed as well as the robust tr...

In recent years, video streaming applications have proliferated the demand for Video Quality Assessment VQA). Reduced reference video quality assessment (RR-VQA) is a category of VQA where certain features (e.g., texture, edges) of the original video are provided for quality assessment. It is a popular research area for various applications such as...

Currently, a fixed set of bitrate-resolution pairs termed bitrate ladder is used in live streaming applications. Similarly, two-pass variable bitrate (VBR) encoding schemes are not used in live streaming applications to avoid the additional latency added by the first-pass. Bitrate ladder optimization is necessary to (i) decrease storage or delivery...

It is well known that the images suffer from blocking artifacts when compressed by JPEG at low quality factors. Since JPEG uses a standard block size of 8×8 pixels, then the locations of blocking artifacts are known and occur at the boundaries of multiples of 8th pixel positions in horizontal and vertical directions. There exist a number of state-o...

p>Adaptive live video streaming applications utilize a predefined collection of bitrate-resolution pairs, known as a bitrate ladder, for simplicity and efficiency, eliminating the need for additional run-time to determine the optimal pairs for each video. These applications do not incorporate two-pass encoding methods due to increased latency. Howe...

p>Adaptive live video streaming applications utilize a predefined collection of bitrate-resolution pairs, known as a bitrate ladder, for simplicity and efficiency, eliminating the need for additional run-time to determine the optimal pairs for each video. These applications do not incorporate two-pass encoding methods due to increased latency. Howe...

Most of the standard image and video codecs are block-based and depending upon the compression ratio the compressed images/videos suffer from different distortions. At low ratios, blurriness is observed and as compression increases blocking artifacts occur. Generally, in order to reduce blockiness, images are low-pass filtered which leads to more b...

In recent years, due to the growth of social networks and development of video sharing platforms, transmission of video content has increased dramatically. This huge amount of data imposes a heavy load on the limited bandwidth of the networks. As a result, data loss will be inevitable. Nevertheless, since some types of video frames, such as B-frame...

Adaptive live video streaming applications utilize a predefined collection of bitrate-resolution pairs, known as a bitrate ladder , for simplicity and efficiency, eliminating the need for additional run-time to determine the optimal pairs during the live streaming session. These applications do not incorporate two-pass encoding methods due to inc...

Recent years have witnessed video streaming demands evolve into one of the most popular Internet applications. With the ever-increasing personalized demands for highdefinition and low-latency video streaming services, networkassisted video streaming schemes employing modern networking paradigms have become a promising complementary solution in the...

In HTTP Adaptive Streaming (HAS), videos are encoded at multiple bitrates and spatial resolutions ( i.e. , representations ) to adapt to the heterogeneity of network conditions, device attributes, and end-user preferences. Encoding the same video segment at multiple representations increases costs for content providers. State-of-the-art multi-encod...

Light field imaging, which captures both spatial and angular information, improves user immersion by enabling post-capture actions, such as refocusing and changing view perspective. However, light fields represent very large volumes of data with a lot of redundancy that coding methods try to remove. State-of-the-art coding methods indeed usually fo...

Opportunistic routing (OR) paradigms in vehicular networks via opportunistic candidate set selection have a better performance over the pre-defined next-hop node in terms of packet delivery rate. Nevertheless, uneven vehicle distribution, highly dynamic topology, varying link interference, and bandwidth restrictions impose drastic challenges for sa...

In live streaming applications, a fixed set of bitrate-resolution pairs (known as bitrate ladder) is generally used to avoid additional pre-processing run-time to analyze the complexity of every video content and determine the optimized bitrate ladder. Furthermore, live encoders use the fastest available preset for encoding to ensure the minimum po...

With the ever-increasing demands for high-definition and low-latency video streaming applications, network-assisted video streaming schemes have become a promising complementary solution in the HTTP Adaptive Streaming (HAS) context to improve users’ Quality of Experience (QoE) as well as network utilization. Edge computing is considered one of the...

We have published the code for this paper

Although subjective test is the most accurate image/video quality assessment tool, it is extremely time demanding. In the past two decades, a variety of objective quality measuring tools, such as SSIM, IW-SSIM, SPSIM, FSIM, etc., have been devised, that well correlate with the subjective tests results. However, the main problem with these methods i...

Recently, several quantum image watermarking (QIW) schemes have been introduced, but they cannot be implemented in today’s quantum systems due to lack of sufficient number of qubits of these systems. Enhancing the quantum transmitter and receiver circuits of these QIW schemes by reducing their number of qubits without increasing their run-time comp...

Gait recognition is an efficient way of identifying people from their walking behavior, using inertial sensors integrated into the smartphones. These inertial sensors such as accelerometers and gyroscopes easily collect the gait data used by the existing deep learning-based gait recognition methods. Although these methods specifically, the hybrid d...

In light field image compression, facilitating random access to individual views plays a significant role in decoding views quickly, reducing memory footprint, and decreasing the bandwidth requirement for transmission. Highly efficient light field image compression methods mainly use inter view prediction. Therefore, they typically do not provide r...

The performance of applications that require frame rendering time estimation or dynamic frequency scaling, rely on the accuracy of the workload model that is utilized within these applications. Existing models lack sufficient accuracy in their core model. Hence, they require changes to the target application or the hardware to produce accurate resu...

The performance of applications that require frame rendering time estimation or dynamic frequency scaling, rely on the accuracy of the workload model that is utilized within these applications. Existing models lack sufficient accuracy in their core model. Hence, they require changes to the target application or the hardware to produce accurate resu...

Tilt and pan camera movements are common in computer games or social media videos. These types of videos contain numerous perspective transforms while today’s video codecs rely on translational and affine motion models for motion compensation. The general perspective motion model with 8 parameters (8PMM) has unreasonably high processing time. In th...

In this paper, blind image quality assessment (IQA) of Gaussian blurred images based on Discrete Fourier Transform (DFT) is proposed. The proposed work is based on the fact that if a positive constant is added to the magnitude of every AC coefficient of an image, then the average value of ratio of AC coefficient magnitude before and after the const...

In live streaming applications, service providers generally use a bitrate ladder with fixed bitrate-resolution pairs instead of optimizing it per title to avoid the additional latency caused to find optimum bitrate-resolution pairs for every video content. This paper introduces an online bitrate ladder construction scheme for live video streaming a...

In Hybrid Cloud Gaming (HCG), as long as the graphical assets are available at the client side, rendering can be performed locally. However, if the client is not able to render all the frames in time, this may result in the frame rate to drop under the target value. This paper presents an Asset-based frame-level hybrid graphics/video rate control m...

Most of the standard image and video codecs are block-based and depending upon the compression ratio the compressed images/videos suffer from different distortions. At low compression ratios, blurriness is observed and as compression increases blocking artifacts occur. Generally, in order to reduce blockiness, images are low-pass filtered which lea...

Abstract The human visual system response to picture quality degradation due to packet loss is very different from the responses of objective quality measures. While video quality due to packet loss may be impaired by at most for one Group of Pictures (GOP), its subjective quality degradation may last for several GOPs. This has a great impact on re...

InIn HTTP Adaptive Streaming (HAS), each video is divided into smaller segments, and each segment is encoded at multiple pre-defined bitrates to construct a bitrate ladder . To optimize bitrate ladders, per-title encoding approaches encode each segment at various bitrates and resolutions to determine the convex hull. From the convex hull, an opti...

Recent studies have revealed that network-assisted techniques, by providing a comprehensive view of the network, improve HTTP Adaptive Streaming (HAS) system performance significantly. This paper leverages the capability of Software-Defined Networking, Network Function Virtualization, and edge computing to introduce a CDN-Aware QoE Optimization in...

High Efficiency Video Coding (HEVC) improves the encoding efficiency by utilizing sophisticated tools such as flexible Coding Tree Units (CTUs) partitioning. The Coding Units (CUs) can be split recursively into four equally sized CUs ranging from 64×64 to 8×8 pixels. At each depth level (or CU size), intra prediction via exhaustive mode search was...

Recently, HTTP Adaptive Streaming (HAS) has become the dominant video delivery technology over the Internet. In HAS, clients have full control over the media streaming and adaptation processes. Lack of coordination among the clients and lack of awareness of the network conditions may lead to sub-optimal user experience, and resource utilization in...

Video delivery over the Internet has been becoming a commodity in recent years, owing to the widespread use of Dynamic Adaptive Streaming over HTTP (DASH). The DASH specification defines a hierarchical data model for Media Presentation Descriptions (MPDs) in terms of segments. This paper focuses on segmenting video into multiple shots for encoding...

High Efficiency Video Coding (HEVC) surpasses its predecessors in encoding efficiency by introducing new coding tools at the cost of an increased encoding time-complexity. The Coding Tree Unit (CTU) is the main building block used in HEVC. In the HEVC standard, frames are divided into CTUs with the predetermined size of up to 64 × 64 pixels. Each C...

Recently, more interest in the different plenoptic formats, including digital holograms, has emerged. Aside from other challenges that several steps of the holographic pipeline, from digital acquisition to display, have to face, visual quality assessment of compressed holograms is particularly demanding due to the distinct nature of this 3D image m...

The high-efficiency video coding (HEVC) standard improves the coding efficiency at the cost of a significantly more complex encoding process. This is an issue for a large number of video-capable devices that operate on batteries, with limited and varying processing power. A complexity controller enables an encoder to provide the best possible quali...

A new variant of image steganography based on exploiting modification directions (EMD) named advanced EMD (AEMD) is introduced. In this method the secret digits in mn -ary notional systems are embedded into a group of n pixels of the cover image. To increase data hiding capacity, edge masking characteristics of human visual system is exploited to e...

Video streaming applications keep getting more attention over the years, and HTTP Adaptive Streaming (HAS) became the de-facto solution for video delivery over the Internet. In HAS, each video is encoded at multiple quality levels and resolutions (i.e., representations) to enable adaptation of the streaming session to viewing and network conditions...

High quality (HQ) video services occupy large portions of the total bandwidth and are among the main causes of congestion at network bottlenecks. Since video is resilient to data loss, throwing away less important video packets can ease network congestion with minimal damage to video quality and free up bandwidth for other data flows. Frame type is...

Although subjective tests are most accurate image/video quality assessment tools, they are extremely time demanding. In the past two decades, a variety of objective tools, such as SSIM, IW-SSIM, SPSIM, FSIM, etc., have been devised, that well correlate with the subjective tests results. However, the main problem with these methods is that, they do...

High-Efficiency Video Coding (HEVC) surpasses its predecessors in encoding efficiency by introducing new coding tools at the cost of an increased encoding time-complexity. The Coding Tree Unit (CTU) is the main building block used in HEVC. In the HEVC standard, frames are divided into CTUs with the predetermined size of up to 64x64 pixels. Each CTU...

The High Efficiency Video Coding (HEVC) is adopted by various video applications in recent years. Because of its high computational demand, controlling the complexity of HEVC is of paramount importance to appeal to the varying requirements in many applications, including power-constrained video coding, video streaming, and cloud gaming. Most of the...

HTTP Adaptive Streaming (HAS) enables high quality streaming of video contents. In HAS, videos are divided into short intervals called segments, and each segment is encoded at various quality/bitrates to adapt to the available channel rate. Multiple encoding of the same content imposes high cost for video content providers. To reduce the time-compl...

Efficient compression plays a significant role in Light Field imaging technology because of the huge amount of data needed for their representation. Video encoders using different strategies are commonly used for Light Field image compression. In this paper, different video encoder implementations including HM, VTM, x265, xvc, VP9, and AV1 are anal...

In this paper, an image steganography method is proposed to overcome the limitations associated with the most existing image steganography methods based on either spatial domain or transform domain. Although these methods try to increase the embedding capacity, the produced quality of the stego-images is still low and the embedding capacity is stil...

HTTP Adaptive Streaming (HAS) is the most common approach for delivering video content over the Internet. The requirement to encode the same content at different quality levels (i.e., representations) in HAS is a challenging problem for content providers. Fast multirate encoding approaches try to accelerate this process by reusing information from...

In conventional multicasting of cellular networks, due to channel diversity of receivers, data rates of the base stations (BS) are limited to ensure all mobile stations (MS) receive packets correctly. This method, besides the increased power consumption, deprives MSs from getting better video quality than they could get at higher bit-rates. This pa...

div>This work proposes a workload model for modern graphics APIs, named GAMORRA, to estimate each frame's workload and possibly predict rendering times on a target hardware. Also, a suite of benchmarks is described that evaluates the performance of the target hardware and the overhead of different graphical operations to be used in the proposed mo...

div>This work proposes a workload model for modern graphics APIs, named GAMORRA, to estimate each frame's workload and possibly predict rendering times on a target hardware. Also, a suite of benchmarks is described that evaluates the performance of the target hardware and the overhead of different graphical operations to be used in the proposed mo...