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Digital Signal and Image Processing

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lightbulbAbout this topic
Digital Signal and Image Processing is a field of study that focuses on the manipulation, analysis, and interpretation of digital signals and images using algorithms and computational techniques. It encompasses various methods for enhancing, transforming, and extracting information from signals and images to improve their quality and facilitate effective communication and analysis.
lightbulbAbout this topic
Digital Signal and Image Processing is a field of study that focuses on the manipulation, analysis, and interpretation of digital signals and images using algorithms and computational techniques. It encompasses various methods for enhancing, transforming, and extracting information from signals and images to improve their quality and facilitate effective communication and analysis.

Key research themes

1. How can digital signal processing techniques be optimized for noise reduction and accurate feature extraction in biomedical signals and images?

This research theme concentrates on improving the quality of biomedical signals and images, such as ECGs and medical images, by effectively removing noise and preserving critical diagnostic information. Noise in biomedical data, arising from diverse sources like baseline wander, power line interference, or acquisition artifacts, can significantly hinder further analysis. Digital signal processing (DSP) methods, including filtering, wavelet-based denoising, and adaptive median filtering, are studied and developed to enhance signal fidelity, reduce distortions, and facilitate accurate diagnosis. The theme also includes lossless recovery methods for medical images to ensure data integrity crucial in life-critical applications.

Key finding: This work implemented a DSP system using MATLAB to remove baseline wander (via detrend function), powerline interference (using a 4th order IIR bandstop filter at 60 Hz), and high-frequency noise (with a 3rd order IIR... Read more
Key finding: Proposed a hybrid denoising algorithm by cascading Adaptive Median Filter (AMF) and Modified Decision Based Median Filter (MDBMF), targeting salt and pepper noise densities from 10% to 90%. The algorithm adaptively identifies... Read more
Key finding: Reviewed noise modeling approaches emphasizing stationary zero-mean white Gaussian noise and introduced wavelet-based denoising schemes that outperform traditional Fourier-based filtering by preserving signal details... Read more
Key finding: Introduced a secure, lossless medical image recovery method that integrates JPEG-LS compression of the region of interest (ROI), bit-plane separation, data reorganization, and encryption using a permutation ordered binary... Read more

2. What advances in image processing transformations, such as wavelet and multiresolution analysis, improve image denoising, compression, and feature extraction?

This theme investigates the application of sophisticated image transformation frameworks—principally wavelet transforms and multiresolution analysis—for enhanced image processing tasks. Wavelets provide space-frequency localization enabling detailed analysis of images at multiple scales and positions, addressing limitations of sinusoidal transforms like DCT. Exploiting this, researchers apply wavelet bases such as Daubechies and Haar for tasks including denoising, edge detection, and compression, capitalizing on the sparse representation of image features and efficient coding.

Key finding: Provided an in-depth overview of wavelet theory and multi-resolution analysis, formalizing the construction of wavelet basis functions like Haar and Daubechies. Demonstrated how discrete wavelet transform decomposes images... Read more
Key finding: Outlined digital image processing essentials including image representation, Fourier analysis, convolution, and advanced methods like wavelets. Emphasized educational software facilitating hands-on learning and incorporation... Read more
Key finding: Detailed mathematical foundations for imaging functions and two-dimensional systems, emphasizing the mapping operators and linear additive systems properties. The text covers spectral and spatial domain methods to process... Read more

3. How can digital watermarking and forgery detection techniques enhance security and authentication in digital images?

This research area focuses on embedding robust, imperceptible digital watermarks within images and developing algorithms to detect manipulations such as splicing or copy-move forgeries. Digital watermarking embeds ownership or authentication information while balancing imperceptibility, robustness to attacks, and capacity. Forgery detection algorithms employ statistical, transform-domain, and machine learning methods (including variants of Benford's law and local binary patterns) to effectively identify tampering even under diverse image processing attacks. These mechanisms are crucial for copyright protection, data integrity, and forensic analysis.

Key finding: Provided a comprehensive classification of digital watermarking based on robustness (robust, fragile, semi-fragile), perceptibility (visible, invisible), and domain (spatial, frequency). Surveyed techniques including least... Read more
Key finding: Developed an image splicing detection algorithm combining statistical features derived from traditional and generalized Benford’s law applied to image mantissa distributions, along with other statistical descriptors.... Read more

All papers in Digital Signal and Image Processing

En este trabajo se utilizaron dos controladores, un controlador moderno óptimo LQR con observador de estados y un controlador inteligente Borroso Proporcional Derivativo (FPD), aplicados a un sistema bola y barra, con el propósito de... more
This paper aims at showing the forms in which the language of humiliation is used by both teachers and students in secondary schools. It also identifies the effects such a language has on students. As such, the article helps understand... more
Los objetos rugosos iluminados por luz láser muestran una apariencia granular llamada speckle . Si la superficie no es rígida, el patrón de speckle también cambia y da cuenta de los procesos dinámicos que tienen lugar en la superficie o... more
Wavelet transform has the good characteristic of time-frequency locality and many researches show that it can perform well for denoising in smooth and singular areas. But it isn't suitable for describing the signals, which have high... more
To strengthen electoral integrity and transparency, the global electoral landscape is shifting towards the adoption of biometric voter registration (BVR) systems to curb duplicate registrations and voter impersonation. While effective in... more
To strengthen electoral integrity and transparency, the global electoral landscape is shifting towards the adoption of biometric voter registration (BVR) systems to curb duplicate registrations and voter impersonation. While effective in... more
Multiple Object Tracking is the process of locating multiple objects over time in a video stream. Object detection and classification are two prior steps before performing tracking over video scene. Object detection is the process of... more
Analysis of convolutional windows in fourier and fractional fourier domain is the main objective of the paper. First, the concept of convolutional windows and its necessity is discussed. Next, basics of Fractional Fourier Transform (FRFT)... more
Multipath decreases the accuracy of the GNSS positioning by distorting the correlation function. Based on this observation it is possible to detect abnormally large multipath error by monitoring the correlation function. Indeed for the... more
En el siguiente articulo se describe el proceso de diseno e implementacion de un software construido haciendo uso del lenguaje de programacion Python y las funciones de la libreria de OpenCV que mediante el uso de procesamiento digital de... more
The following article has a number of tools implemented in Matlab in order to improve x-ray images to confirm or discard fractures and fissures that may be imperceptible to the human eye due to its poor ability of not being able to... more
The aim of the study was a selection of best ECG leads to get the significant T-wave alternans signal (TWA). The group of 16 patients with implantable cardioverterdefibrillator (ICD) was examined. The 64 lead ECG system was used. Three... more
This paper describes the design and engineering of a wireless control system for smoke and fire detection with alarming provision, sms sending and fire extinguishing by a vehicle. We chose the PIC microcontroller for the controlling of... more
This paper introduces a method for removal of salt-and-pepper impulsive noise from images while preserving edges and fine details. The method consists of two stages: detection and filtering. In the detection stage, two conditions must be... more
To protect the information integrity of the medical images, this paper proposes a secure lossless recovery scheme for medical images based on image block compression and permutation ordered binary (POB) number system, which includes two... more
Occlusion is a big challenge for facial expression recognition (FER) in real-world situations. This study investigates three different methods of feature extraction for facial expression recognition from occluded images. The Gabor filters... more
Emotion could be expressed through unimodal social behaviour's or bimodal or it could be expressed through multimodal. This survey describes the background of facial emotion recognition and surveys the emotion recognition using visual... more
Local repolarization changes in the myocardium can be noninvasively identified by an inverse solution using multichannel measurements of ECG potentials and QT integral maps in situation with and without changed repolarization. In this... more
Repolarization changes in small areas of myocardium can be detected from difference integral maps computed from body surface potentials measured on the same subject in situations with and without manifestation of ischemia. Detection was... more
Linear algebra serves as the foundation for numerous fields of mathematics and finds extensive applications across various disciplines, including physics, engineering, computer science, economics, and statistics. This research paper... more
Linear algebra serves as the foundation for numerous fields of mathematics and finds extensive applications across various disciplines, including physics, engineering, computer science, economics, and statistics. This research paper... more
The picture quality of an underwater image affected by several factors, e.g. light absorption, turbidity, structure less environment and scattering effects etc. The quality enhancements of underwater images were previously performed by... more
Emotion estimation is a field that has been studied for a long time, and sev- eral approaches using machine learning models exist. In this paper, we present an LSTM model that utilizes Blendshapes produced by the MediaPipe library to... more
RESUMEN En este documento se presenta la metodologia para implementar un controlador de presion de combustible basado en logica difusa y la comparacion de su desempeno con un controlador PID clasico. El procedimiento de diseno del... more
Facial emotion recognition (FER) is a crucial task in human communication. Various face emotion recognition models were introduced but often struggle with generalization across different datasets and handling subtle variations in... more
Edge-based applications are envisaged to have a paramount impact on the academic landscape. One of the key aspects of academic activities is to keep the learners engaged. The pertinent engagement activities require constant analysis of... more
Soft image delivery uses pseudo-analog modulation for wireless image transmissions to prevent cliff and leveling effects subject to channel quality fluctuation and to realize graceful quality improvement according to wireless channel... more
Facial expression recognition (FER) is an essential task in computer vision that has a wide range of applications, including human-computer interaction and affective computing. This study involved a thorough analysis to compare the... more
In this study, a new watermarking system was proposed to address two major concerns: slow learning and computational capability. At first, cover image was transformed into wavelet environment utilizing Integer Wavelet Transform (IWT) that... more
With the progress of Facial Expression Recognition (FER) from research laboratorycontrolled to testing in-the-wild conditions and the new accomplishment of Deep learning strategies in different fields, deep neural Networks have... more
Tracking regular expenses is essential for maintaining a budget and ensuring financial health. Many individuals still rely on traditional methods, such as pen-and-system records or spreadsheets, to track their spending. These methods,... more
The aim of the study was to simulate T-wave alternans (TWA) magnitude distribution maps on the body surface employing ECGSIM program and then to compare obtained results with data measured from patients. The toolbox for ECGSIM program was... more
The aim of this study was to investigate the application of wavelet denoising in noise reduction of multichannel high resolution ECG signals. In particular, the influence of the selection of wavelet function and the choice of... more
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