Abstract Facial emotion recognition (FER) represents a significant outcome of the rapid advancements in artificial intelligence (AI) technology. In today's digital era, the ability to decipher emotions from facial expressions has evolved into a fundamental mode of human interaction and communication. As a result, FER has penetrated diverse domains, including but not limited to medical diagnosis, customer feedback analysis, the automation of automobile driver systems, and the evaluation of student comprehension. Furthermore, it has matured into a captivating and dynamic research field, capturing the attention and curiosity of contemporary scholars and scientists. The primary objective of this paper is to provide an exhaustive review of FER systems. Its significance goes beyond offering a comprehensive resource; it also serves as a valuable guide for emerging researchers in the FER domain. Through a meticulous examination of existing FER systems and methodologies, this review equips them with essential insights and guidance for their future research pursuits. Moreover, this comprehensive review contributes to the expansion of their knowledge base, facilitating a profound understanding of this rapidly evolving field. In a world increasingly dependent on technology for communication and interaction, the study of FER holds a pivotal role in human‐computer interaction (HCI). It not only provides valuable insights but also unlocks a multitude of possibilities for future innovations and applications. As we continue to integrate AI and facial emotion recognition into our daily lives, the importance of comprehending and enhancing FER systems becomes increasingly evident. This paper serves as a stepping stone for researchers, nurturing their involvement in this exciting and ever‐evolving field.

Abstract Human Activity Recognition (HAR) is a highly promising research area meant to automatically identify and interpret human behaviour using data received from sensors in various contexts. The potential uses of HAR are many, among them health care, sports coaching or monitoring the elderly or disabled. Nonetheless, there are numerous hurdles to be circumvented for HAR's precision and usefulness to be improved. One of the challenges is that there is no uniformity in data collection and annotation making it difficult to compare findings among different studies. Furthermore, more comprehensive datasets are necessary so as to include a wider range of human activities in different contexts while complex activities, which consist of multiple sub‐activities, are still a challenge for recognition systems. Researchers have proposed new frontiers such as multi‐modal sensor data fusion and deep learning approaches for enhancing HAR accuracy while addressing these issues. Also, we are seeing more non‐traditional applications such as robotics and virtual reality/augmented world going forward with their use cases of HAR. This article offers an extensive review on the recent advances in HAR and highlights the major challenges facing this field as well as future opportunities for further researches.

Forensic Science is a branch of science that deals with the discovery, examination, and analysis of strong elements or evidence involved in the criminal justice system. It involves the use of scientific methods to investigate crimes. The Gender Classification System is closely linked to forensic studies, specifically investigating individuals through their handwriting, known as Behavioral Biometrics. Biometric systems rely on behavioral and physiological traits such as brain-prints, fingerprints, handwritten text, speech, facial attributes, gait information, palm vein patterns, hand geometry, electrocardiograms (ECGs), and more. Gender classification is an intriguing and important aspect within the field of pattern recognition and machine learning. It involves a binary problem of classifying individuals as either male or female. Analyzing the differences in femininity and masculinity behaviors can contribute to the evaluation of biometric-based identification systems. Gender classification has numerous forensic applications, including crime identification, demographic research, forgery detection, security, and surveillance. The main objective of this article is to present the latest survey findings on the gender classification system based on handwritten text, specifically the behavioral biometric modality. It includes an overview of the state-of-the-art work, the general framework, approaches, biometric modalities, and critical analysis. The article concludes with a critical analysis, discussion of open issues, concluding remarks, and future perspectives.

In this article, the authors present an effort to recognize handwritten Gurumukhi place names for use in postal automation. Five feature extraction techniques (zoning, horizontal peak extent, vertical peak extent, diagonal, and centroid) have been analyzed and optimized using Principal Component Analysis (PCA). Four classification methods ( k -Nearest Neighbor ( k -NN), decision tree, random forest, and Convolutional Neural Network (CNN)) have been utilized to classify the handwritten word images. To enhance the recognition results, the authors have employed Bootstrap Aggregation (Bagging) with a majority voting scheme. The authors used a public benchmark dataset of 40,000 handwritten place-name samples in the Punjabi language for their experimental work. The experiments were conducted using a 70:30 partitioning approach, where 70% of the data was utilized for training and the remaining 30% for testing. The system achieved a maximum recognition accuracy of 96.98% by utilizing a combination of zoning, vertical peak extent, and diagonal features, and a minimum Mean Squared Error (MSE) of 0.86% based on a combination of zoning and horizontal peak extent features with a majority voting scheme through ensemble (Bagging) methodology.

The use of computer programs in breaching web site security is common today. CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) and human interaction proofs are the cost-effective solution to these kinds of computer attacks on web sites. These CAPTCHAs are available in many forms, such as those based on text, images and audio. A CAPTCHA must be secure enough that it cannot be broken by a computer program, and it must be usable enough that humans can easily understand it. The most popular is the text-based scheme. Most text-based CAPTCHAs are based on the English language and are not usable by the native people of India. Research has proven that native people are more comfortable with native language–based CAPTCHA. Devanagari-based CAPTCHAs are also available, but the security aspect has not been tested. Unfortunately, English language–based CAPTCHAs are successfully broken. Therefore, it is important to test the security of Devanagari script-based CAPTCHAs. We picked five unique monochrome CAPTCHAs and five unique greyscale CAPTCHAs for testing security. We achieved 88.13% to 97.6% segmentation rates on these schemes and generated six types of features for these segmented characters, such as raw pixels, zoning, projection, Scale-Invariant Feature Transform (SIFT), Speeded-Up Robust Features (SURF) and Oriented Fast and Rotated BRIEF (ORB). For classification, we used three classifiers for comparative analyses. Using k-Nearest Neighbour (k-NN), Support Vector Machine (SVM) and Random Forest, we achieved high recognition on monochrome and greyscale schemes. For monochrome Devanagari CAPTCHAs, the recognition rate of k-NN ranges from 64.78% to 82.39%, SVM ranges from 76.46% to 91.34% and Random Forest ranges from 80.34% to 91.28%. For greyscale Devanagari CAPTCHAs, the recognition rate of k-NN ranges from 67.52% to 85.47%, SVM ranges from 76.9% to 91.71% and Random Forest ranges from 83.07% to 92.13%. We achieved a breaking rate for monochrome schemes of 66% to 85% and for greyscale schemes of 73% to 93%.