Tawaf crowd simulation using reciprocal velocity obstacle

Studies on crowd simulation have been around us for nearly 30 years. It remains one of the important and fundamental fields in three-dimensional (3D) computer graphics. Simulating large amount of crowds such as the crowd during Hajj is never an easy task. Therefore, a more refined technique is needed to avoid the entities, agents or characters in Hajj crowd from colliding with each other. In order to simulate such a huge crowd, the reciprocal velocity obstacles concept is used. The simulation is made using the reciprocal velocity obstacles as the collision avoidance technique. An experiment with up to 200 pilgrims is then conducted on four different personal computers (PCs) with different specifications

Towards a realistic marker-based augmented reality scene: issues and prospective aspect

This paper describes the main problems in realistic Augmented Reality scenes. In order to view the real world with additional computer-generated information in a seamless and realistic integration, there are several research challenges that can be identified; some related to camera tracking, system design, user interaction, and rendering. The focus on each of these aspects was thoroughly explored by several methods and techniques. This study is considered to be an exploration for an Augmented Reality rendering technique. This technique focuses on increasing the realism in the AR scene. Thus, in order to realize the AR scene in a more realistic way, there are four main issues; light source detection, well-designed virtual objects that can have true reflex of the real environment, then integration of a real-time accurate soft shadow

An Overview on Base Real-Time Shadow Techniques in Virtual Environments

Shadows are elegant to create a realistic scene in virtual environments. Variety types of shadow techniques encourage us to prepare an overview on all base shadow techniques. Non real-time and real-time techniques are big subdivision of shadow generation. In non real-time techniques ray tracing, ray casting and radiosity are well known and deeply described. Radiosity implemented to create very realistic shadow on non real-time scene. Although traditional radiosity algorithm is difficult to implement, we have proposed a simple one. The proposed pseudo code is easier to understand and implement. Ray tracing used to prevent of collision of movement objects. Projection shadow, shadow volume and shadow mapping are used to create real-time shadow in virtual environments. We have used projection shadow for some objects are static and have shadow on flat surface. Shadow volume used to create accurate shadow with sharp outline. Shadow mapping that is the base of most recently techniques is reconstructed. The reconstruct algorithm gives some new idea to propose another algorithm based on shadow mapping.  

A study on image segmentation techniques used in color detection

to humans, an image is a meaningful arrangement of regions and objects, whereas to computers, an image is merely a random collection of pixels. This work exploits some of the techniques based on the extraction of the color of an image in the real-time environment. Image segmentation is an intense research area in Computer Vision, however, enhancements or results still on to produce accurate segmentation results for images. Relating with other surveys that compare multiple techniques, this paper takes the advantage to select of the most used technique(s), Our study may be helpful for Augmented Reality environment, object detection and tracking as well as other real -time technologies. Interested reader will obtain know ledge on various categories and types of research challenges In the image-based segmentation within the scope of colored images environments

Speech emotion classification using SVM and MLP on prosodic and voice quality features

In this paper, a comparison of emotion classification undertaken by the Support Vector Machine (SVM) and the Multi-Layer Perceptron (MLP) Neural Network, using prosodic and voice quality features extracted from the Berlin Emotional Database, is reported. The features were extracted using PRAAT tools, while the WEKA tool was used for classification. Different parameters were set up for both SVM and MLP, which are used to obtain an optimized emotion classification. The results show that MLP overcomes SVM in overall emotion classification performance. Nevertheless, the training for SVM was much faster when compared to MLP. The overall accuracy was 76.82% for SVM and 78.69% for MLP. Sadness was the emotion most recognized by MLP, with accuracy of 89.0%, while anger was the emotion most recognized by SVM, with accuracy of 87.4%. The most confusing emotions using MLP classification were happiness and fear, while for SVM, the most confusing emotions were disgust and fear

Atmospheric cloud modeling methods in computer graphics: A review, trends, taxonomy, and future directions

The modeling of atmospheric clouds is one of the crucial elements in the natural phenomena visualization system. Over the years, a wide range of approaches has been proposed on this topic to deal with the challenging issues associated with visual realism and performance. However, the lack of recent review papers on the atmospheric cloud modeling methods available in computer graphics makes it difficult for researchers and practitioners to understand and choose the well-suited solutions for developing the atmospheric cloud visualization system. Hence, we conducted a comprehensive review to identify, analyze, classify, and summarize the existing atmospheric cloud modeling solutions. We selected 113 research studies from recognizable data sources and analyzed the research trends on this topic. We defined a taxonomy by categorizing the atmospheric cloud modeling methods based on the methods' similar characteristics and summarized each of the particular methods. Finally, we underlined several research issues and directions for potential future work. The review results provide an overview and general picture of the atmospheric cloud modeling methods that would be beneficial for researchers and practitioners

An Approach to Minimising Estimated Pincushion Camera Distortions

 Minimizing camera distortion has been a focus of recent photorealism researches. Of the several types of camera distortions, researchers concentrated on the radial distortion being the most severe part of the total lens aberrations. Often, polynomial approximations by introducing distortion-specific parameters into the camera model have been methods of evaluating distortions. Of the two types of radial distortions, barrel, is the most discussed probably because of its dominance in cheap wide-angle lenses. In this paper, an approach to estimating and minimizing pincushion distortion by using fundamental surface area properties of the distorted image is proposed. This paper is significant as it reveals the importance of the topic and its implications on the camera. Demonstrations using four camera lenses show the robustness of this technique under different focal lengths conditions. The reliability of the approach is justified by comparing the results with the physical observations using (two tailed) t-test statistic.

Method of registration for 3D face point cloud data

This paper analyzes the techniques that can be used to perform point cloud data registration for a human face. We found that there is a limitation in full scale viewing on the input data taken from 3D camera which is only represented the front face of a man as the point of view of a camera. This has caused a hole on the surface that is not filled with the point cloud data. This research is done by mapping the retrieved point cloud to the surface of the face template of the human head. By using Coherent Point Drift (CPD) algorithm which is one of the non-rigid registration techniques, the analysis has been done and it shows that the mapping of points for a three-dimensional (3D) face is not done properly where there are some surfaces work well and certain points spread into the wrong area. Consequently, it has resulted in registration failure occurrences due to the concentration of the points which is focusing on the face only