Koksheik Wong

• Ph.D
• Professor (Associate) at Monash University Malaysia, Malaysia

Image watermarking plays a vital role in providing protection from copyright violation. However, conventional watermarking techniques typically exhibit trade-offs in terms of image quality, robustness and capacity constrains. More often than not, these techniques optimize on one constrain while settling with the two other constraints. Therefore, in...

The use of Unmanned Aerial Vehicles (UAVs) for military as well as civilian applications such as search and rescue operations, disaster management, parcel delivery and agriculture, is becoming increasingly popular, mainly due to their versatile nature and relatively inexpensive operating costs. However, one of the most significant barriers in the w...

As an essential part of music, main melody is the cornerstone of music information retrieval. In the MIR’s sub-field of main melody extraction, the mainstream methods assume that the main melody is unique. However, the assumption cannot be established, especially for music with multiple main melodies such as symphony or music with many harmonies. H...

With the development of computational science, many fields, including computational linguistics (sequence processing) and computational vision (image processing), have enabled various applications and automation with satisfactory results. However, the development of Computational Music Analysis (CMA) is still in its infancy. The main factor hinderi...

High-dynamic range (HDR) images are circulated rapidly over the internet with risks of being exploited for unauthenticated usage. To protect these images, some HDR image based watermarking (HDR-IW) methods were put forward. However, they inherited the same problem faced by conventional IW methods for standard dynamic range (SDR) images, where only...

Human-Object Interaction (HOI) detection recognizes how persons interact with objects, which is advantageous in autonomous systems such as self-driving vehicles and collaborative robots. However, current HOI detectors are often plagued by model inefficiency and unreliability when making a prediction, which consequently limits its potential for real...

Behavioral biometrics is an emerging trend due to their cost-effectiveness and non-intrusive implementations that support remote access for user identification. This is the case especially in recent times of social distancing and working from home arrangements, where online attendance is the preferred option in contrast to physical presence. In thi...

Classifying music pieces based on their instrument sounds is pivotal for analysis and application purposes. Given its importance, techniques using machine learning have been proposed to classify violin and viola music pieces. Violin and viola are two different instruments with three overlapping strings of the same notes, and it is challenging for o...

Background The malaria risk prediction is currently limited to using advanced statistical methods, such as time series and cluster analysis on epidemiological data. Nevertheless, machine learning models have been explored to study the complexity of malaria through blood smear images and environmental data. However, to the best of our knowledge, no...

Hashing technology gains much attention in protecting the biometric template lately. For instance, Index-of-Max (IoM), a recent reported hashing technique, is a ranking-based locality sensitive hashing technique, which illustrates the feasibility to protect the ordered and fixed-length biometric template. However, biometric templates are not always...

The interest in real-time micro-expression recognition has increased with the current trend in human-computer interaction applications. Presently, there are several approaches which include geometrical analysis for fast facial muscle movement feature representations. However, due to the subtleness of emotions, recognition accuracy remains a challen...

Covert wireless communication aims to hide the existence of certain transmissions in a network in order to achieve secrecy. One such network that could greatly benefit from covert communication is multi-UAV networks that operate without a fixed infrastructure or administrative support. In such a setting, the nodes communicate directly among each ot...

JPEG is the most commonly utilized image coding standard for storage and transmission purposes. It achieves a good rate–distortion trade-off, and it has been adopted by many, if not all, handheld devices. However, often information loss occurs due to transmission error or damage to the storage device. To address this problem, various coefficient re...

Traditionally, encryption is applied to mask the semantic of a content, while data insertion adds data to a content for management purpose. In this work, a joint encryption and data insertion method is proposed. The input image is divided into 2 parts, where the first part is manipulated to mask the perceptual semantics, while the second part is pr...

Conventional data hiding methods for PDF file insert a payload data by slightly modifying the position of characters in a document. Even if the changes are small, a certain degree of visual distortion is inevitably introduced to the PDF file. In this work, we propose a new data hiding method that splits the space value between characters. Specifica...

Autonomous passenger counting in public transportation represents an integral part of an intelligent transportation system, as it provides vital information to improve the efficiency and resource management of a public transportation network. However, counting passengers in highly crowded scenes is a challenging task due to their random movement, d...

With the increasing number of video applications, it is essential to resolve issues such as ineffective search of video content, tampered/forged video content, packet loss, to name a few. Data embedding is typically utilized as one of the solutions to address the aforementioned issues. One of the important requirements of data embedding is to maxim...

With the rapid advancement in digital technologies, video rises to become one of the most effective communication tools that continues to gain popularity and importance. As a result, various proposals are put forward to manage videos, and one of them is data embedding. Essentially, data embedding inserts data into the video to serve a specific purp...

In this work, we show the generative capability of an image classifier network by synthesizing high-resolution, photo-realistic, and diverse images at scale. The overall methodology, called Synthesize-It-Classifier (STIC), does not require an explicit generator network to estimate the density of the data distribution and sample images from that, bu...

It is vital to authenticate the content of speech signals to prevent the framing of innocent individuals. Furthermore, lack of speech content authentication may lead to repudiation. The research problem of authenticity vs falsehood is timely considering the recent worldwide interest in fake news and viral manipulated media. Liu & Wang proposed an a...

In the last few years, with the increasing popularity of cloud computing and the availability of mobile smart devices as well as ubiquitous network connections, more and more users are uploading their personal data to remote servers. However, this can lead to significant security breaches, where confidentiality, integrity and authentication are con...

A technique is put forward to hide data into an animated GIF by exploiting the transparent pixels. Specifically, a new frame is crafted based on the data to be embedded. The newly crafted frame is inserted between 2 existing frames, and the delay time of the affected frames are adjusted accordingly to achieve complete imperceptibility. To the best...

Lane departure warning is one important feature in Advanced Driver Assistance Systems (ADAS), which aims to improve overall safety on the road. However, challenges such as inconsistent shadows and fading lane markings often plague the road surface and cause the lane detection system to produce false warnings. Users are aggravated by the warning and...

The epidemic of gun violence worldwide necessitates the need for an active-based video surveillance network to combat this crime. In this context, autonomously detecting handguns is crucial in capturing firearm-related crimes. However, current object detectors using deep learning are unable to capture handguns at different scales in an unconstraine...

This paper proposes a robust image watermarking method based on the non-Newtonian effect in fluid dynamics and multiple interpolated transformations. First, the host image is encrypted by using a k-level Arnold map, followed by Discrete Wavelet Transformation. Second, the watermark is inserted into the encrypted-transformed host image, where the re...

Background: Publicly available genome data provides valuable information on the genetic variation patterns across different modern human populations. Neuropeptide genes are crucial to the nervous, immune, endocrine system, and physiological homeostasis as they play an essential role in communicating information in neuronal functions. It remains un...

Fingerprint is the most well-known and successfully deployed biometric modalities in view of its ease of acquisition, established use, acceptance and high recognition rate (i.e., robustness). This is also due in part to its use in crime scene investigations to link crimes to suspected individuals. One form of fingerprint is called the latent finger...

In any application of watermarking, the selection of feature vectors from a given multimedia content is important from the perspective of robustness and security. In the case of PDF document, the spaces between words and characters are commonly utilized for embedding watermark in the conventional schemes. Instead of modifying the space values direc...

With massive utilization of video in every aspect of our daily lives, managing videos is crucial and demanding. The rich literature of data embedding has proven its viability in managing as well as enriching videos and other multimedia contents, but conventional methods are designed to operate in the media/compression layer. In this work, the synch...

Egocentric Vision (EV) has recently become one of the emerging areas in computer vision. It is a process of recording a person’s activity by using a wearable camera installed on the head of that person to gain an exclusive viewpoint. This field has gained more attention recently due to the wide availability of wearable cameras commercially and the...

Over the years, many biometric template protection schemes, primarily based on the notion of "cancelable biometrics" have been proposed. A cancelable biometric algorithm needs to satisfy four biometric template protection criteria, i.e., irreversibility, revocability, unlinkability, and performance preservation. However, a systematic analysis of ir...

This paper proposes a new feature selection framework for machine learning-based phishing detection system, called the Hybrid Ensemble Feature Selection (HEFS). In the first phase of HEFS, a novel Cumulative Distribution Function gradient (CDF-g) algorithm is exploited to produce primary feature subsets, which are then fed into a data perturbation...

Smart meters are progressively deployed to replace its antiquated predecessor to measure and monitor consumers’ consumption in smart grids. Although smart meters are equipped with encrypted communication and tamper-detection features, they are likely to be exposed to multiple cyber attacks. These meters may be easily compromised to falsify meter re...

A joint encryption and authentication scheme for HEVC compressed video is proposed in this work. It produces a HEVC format compliant video stream that permits the authentication process to be carried out irregardless of the video being in the encrypted or plaintext (i.e., decrypted) form. To achieve this separable property, one set of syntax elemen...

With the advent of mobile smart devices and ubiquitous network connections, digital images can now be conveniently captured, edited, and shared online worldwide. The ever-increasing number of pictures poses a technically challenging, yet unavoidable problem of efficiently and accurately finding a desired image. In this work, we develop a new image...

This paper proposes an enhanced discrete-time Markov chain algorithm in predicting dominant speaker(s) for multipoint video communication system in the presence of transient speech. The proposed algorithm exploits statistical properties of the past speech patterns to accurately predict the dominant speaker for the next time state. Non-linear weight...

Micro-expressions can occur when a person attempts to conceal and suppress his true feelings and emotions, both deliberately or unconsciously.In recent years, facial micro-expression analysis has received tremendous attention in the field of psychology, media and computer vision. However, due to its subtlety and brief duration, development of autom...

The fingerprint is arguably the most successfully deployed biometric data in a broad spectrum of applications for identification and verification purposes. While fingerprint matching algorithms are fairly matured, most studies have so far focused on improving the matching precision, and some effort has been channelled to combat spoofing attacks on...

The utility providers are estimated to lose billions of dollars annually due to energy theft. Although the implementation of smart grids offers technical and social advantages, the smart meters deployed in smart grids are susceptible to more attacks and network intrusions by energy thieves as compared to conventional mechanical meters. To mitigate...

With the development of powerful image processing tools and the increasing trend of using images as the main carrier of information, digital image forgery has become an increasingly serious issue. In copy-move forgery, one part of an image is copied and placed elsewhere in the same image. This paper puts forward an effective method based on SIFT fo...

Ocular recognition is expected to provide a higher flexibility in handling practical applications as oppose to the iris recognition, which only works for the ideal open-eye case. However, the accuracy of the recent efforts is still far from satisfactory at uncontrollable conditions, such as eye blinking which implies any poses of eyes. To address t...

The advancement of cryptography and cryptanalysis has driven numerous innovations over years. Among them is the treatment of cryptanalysis on selectively encrypted content as a recovery problem. Recent research has shown that linear programming is a powerful tool to recover unknown coefficients in DCT-transformed images. While the time complexity i...

In this work, an image encryption method is proposed based on fuzzy cellular neural network (FCNN). First, the shortcomings of FCNN in encrypting image are identified, and the FCNN model is then modified to address these shortcomings. Specifically, a theoretical framework is developed to identify the values of the parameters of FCNN to generate cha...

In this work, we propose a scrambling framework for block transform compressed image. First, three attacks are proposed to sketch the outline of the original image directly from its scrambled counterpart by exploiting information deduced from the transformed components. Based on the proposed sketch attacks, a scrambling framework aiming to minimize...

Recently, micro-expression recognition has seen an increase of interest from psychological and computer vision communities. As micro-expressions are generated involuntarily on a person’s face, and are usually a manifestation of repressed feelings of the person. Most existing works pay attention to either the detection or spotting of micro-expressio...

Nowadays, videos are mostly multiplexed with audios and wrapped in a multimedia container format. With speedy consumption of videos being a norm these days, authenticating video files (video + audio) becomes a challenging task. Conventional authentication schemes only focus on individual track such as audio or video. Therefore, in this work, we pro...

An HEVC format-compliant joint selective encryption and data embedding technique is proposed. The proposed technique is separable, where the decryption and data extraction processes are independent, with minimal parsing overhead. Specifically, elements in the HEVC coding structure are divided into two groups, where one group is manipulated to perce...

This paper proposes a phishing detection technique based on the difference between the target and actual identities of a webpage. The proposed phishing detection approach, called PhishWHO, can be divided into three phases. The first phase extracts identity keywords from the textual contents of the website, where a novel weighted URL tokens system b...

In this work, we propose a novel sketch attack for H.264/AVC format-compliant encrypted video. We briefly describe the notion of sketch attack, review the conventional sketch attacks designed for DCT based compressed image, and identify their shortcomings when applied to attack compressed video. Specifically, the conventional DCT based sketch attac...

A multi-layer authentication scheme for HEVC compressed video is proposed. The combination of CU sizes, which is unique to HEVC and sensitive to video manipulation, is considered along with other elements in the HEVC coding standard to generate the authentication tag. Temporal dependency was enforced, where the authentication tag generated in one s...

Optical strain is an extension of optical flow that is capable of quantifying subtle changes on faces and representing the minute facial motion intensities at the pixel level. This is computationally essential for the relatively new field of spontaneous micro-expression, where subtle expressions can be technically challenging to pinpoint. In this p...

Optical strain is an extension of optical flow that is capable of quantifying subtle changes on faces and representing the minute facial motion intensities at the pixel level. This is computationally essential for the relatively new field of spontaneous micro-expression, where subtle expressions can be technically challenging to pinpoint. In this p...

Despite recent interest and advances in facial micro-expression research, there is still plenty room for improvement in terms of micro-expression recognition. Conventional feature extraction approaches for micro-expression video consider either the whole video sequence or a part of it, for representation. However, with the high-speed video capture...

Despite recent interest and advances in facial micro-expression research, there is still plenty room for improvement in terms of micro-expression recognition. Conventional feature extraction approaches for micro-expression video consider either the whole video sequence or a part of it, for representation. However, with the high-speed video capture...

Recent advancements in high resolution scalable video coding have significantly increased the computational complexities of watermarking solutions for real-time video encoding systems. This paper proposes a human visual system based watermarking algorithm for spatial scalable coding based on the H.264/SVC standard. The proposed algorithm extracts t...