• The Journal of the Korea Contents Association
• /
• v.8 no.4
• /
• pp.17-29
• /
• 2008

In Computer Graphics, fluid dynamics is used for animating and expressing the various special effects of water. As the hardware performance is getting higher, the several algorithms for fluid dynamics become to be executed in real time. However, it still requires a lot of computational time to get the realistic and detailed results. Therefore, there are many researches on the techniques of balancing between performance and quality. It must give priority to the executive performance preserving the visual reality even though sacrificing the physical reality, specially in applications with the game context which need to express the interaction between 3D objects and the surface of the water such as the sea or a lake. In this paper, we propose a method for the realtime animation of interactions between 3D objects and the surface of the water using the linear convolution of height fields and the bounding spheres of object.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.11 no.7
• /
• pp.677-684
• /
• 2016

With the increase of multimedia information such as image, researches on extracting high-level semantic information from low-level visual information has been realized, and in order to automatically generate this kind of information. Various technologies have been developed. Generally, image retrieval is widely preceded by comparing colors and shapes among images. In some cases, images with similar color, shape and even meaning are hard to retrieve. In this article, in order to retrieve the object in an image, technical value of middle level is converted into meaning value of middle level. Furthermore, to enhance accuracy of segmentation, K-means algorithm is engaged to compute k values for various images. Thus, object retrieval can be achieved by segmented low-level feature and relationship of meaning is derived from ontology. The method mentioned in this paper is supposed to be an effective approach to retrieve images as required by users.

• Journal of Korean Society for Geospatial Information Science
• /
• v.21 no.2
• /
• pp.35-43
• /
• 2013

Georeferenced SLI(Street-Level Imagery) services such as Google Streetview, which contain abundant information about the real world, can increase its applicability substantially through conflation with other spatial datasets. For this purpose, we propose a method to improve a correspondence of building region to combine building information more accurately. First, the spatial inconsistency between SLI and vector map is removed by alignment based on road intersections. Then, visible building regions are searched from the spatial inconsistency-removed vector map, and the optimal corresponding building areas are determined in the SLI scene using the visible regions as seed information. The experimental results demonstrated that our method had improved the accuracy of building region correspondence by about 8%. Therefore, our method can be utilized effectively for enhancement of conflation service based on the SLI.

• Journal of the Korea Society of Computer and Information
• /
• v.18 no.1
• /
• pp.21-29
• /
• 2013

The current software for creating and editing animation offers the possibility of dividing variable objects into layers. This paper suggests a method to render and edit each of right and left layer in the process of creating a 3D stereoscopic animation. It is possible to apply a variety of effects to left and right images and to adjust the gap of binocular parallax through this method so that wider variation of images and richer sense of depth can be produced. In addition, this method offers freedom of deleting and inserting an object, controlling size and position of the object and adjusting the gap of binocular parallax. Thus, new sense of depth can be obtained. This method shows the results to apply various effects on the 3D stereoscopic image and to reduce visual fatigue rather than the method to render simultaneously both of left and right layer.

• Journal of the Korea Society of Computer and Information
• /
• v.16 no.7
• /
• pp.49-58
• /
• 2011

Augmented Reality(AR) assists human's cognitive ability through the information visualization by substantiating information about virtual situation. This technology is studied in a variety of ways including education, design, industry, and so on, by various supply of information devices equipped with cameras and display monitors. Since the most of the AR system depends on limited interaction that responds to the order from user, it can not reflect diverse real world situation. In this study, we suggest a knowledge based augmented reality system, which is composed of context awareness agent that provides recognized context information, along with knowledge based component that provides intelligent capability by utilizing domain knowledges. With this capability, the augmented object can generate dynamic model intelligently by reflecting context information, and can make the interaction possible among the multiple objects. We developed rule based context awareness system along with 3D model generation, and tested interaction among the augmented objects. And we suggest a framework that can provide a convenient way of developing augmented reality system for user.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.42 no.3 s.303
• /
• pp.73-80
• /
• 2005

Recently there have been many efforts to support searching and browsing based on the visual content of image and multimedia data. Most existing approaches to content-based image retrieval rely on query by example or user based low-level features such as color, shape, texture. But these methods of query are not easy to use and restrict. In this paper we propose a method for automatic color object extraction and labelling to support multiple queries of content-based image retrieval system. These approaches simplify the regions within images using single colorizing algorithm and extract color object using proposed Color and Spatial based Binary tree map(CSB tree map). And by searching over a large of number of processed regions, a index for the database is created by using proposed labelling method. This allows very fast indexing of the image by color contents of the images and spatial attributes. Futhermore, information about the labelled regions, such as the color set, size, and location, enables variable multiple queries that combine both color content and spatial relationships of regions. We proved our proposed system to be high performance through experiment comparable with another algorithm using 'Washington' image database.

• Journal of Korean Society for Geospatial Information Science
• /
• v.24 no.1
• /
• pp.89-98
• /
• 2016

In this paper, we proposed an automated areal feature matching method based on geometric similarity without user intervention and is applied into areal features of many-to-many relation, for confusion of spatial data-sets of different scale and updating cycle. Firstly, areal feature(node) that a value of inclusion function is more than 0.4 was connected as an edge in adjacency matrix and candidate corresponding areal features included many-to-many relation was identified by multiplication of adjacency matrix. For geometrical matching, these multiple candidates corresponding areal features were transformed into an aggregated polygon as a convex hull generated by a curve-fitting algorithm. Secondly, we defined matching criteria to measure geometrical quality, and these criteria were changed into normalized values, similarity, by similarity function. Next, shape similarity is defined as a weighted linear combination of these similarities and weights which are calculated by Criteria Importance Through Intercriteria Correlation(CRITIC) method. Finally, in training data, we identified Equal Error Rate(EER) which is trade-off value in a plot of precision versus recall for all threshold values(PR curve) as a threshold and decided if these candidate pairs are corresponding pairs or not. To the result of applying the proposed method in a digital topographic map and a base map of address system(KAIS), we confirmed that some many-to-many areal features were mis-detected in visual evaluation and precision, recall and F-Measure was highly 0.951, 0.906, 0.928, respectively in statistical evaluation. These means that accuracy of the automated matching between different spatial data-sets by the proposed method is highly. However, we should do a research on an inclusion function and a detail matching criterion to exactly quantify many-to-many areal features in future.

• Korean Journal of Construction Engineering and Management
• /
• v.14 no.5
• /
• pp.74-83
• /
• 2013

Most current BIM systems are focused on the visual information of work status in the design and construction stages. In a passive BIM system, 3D CAD tool can visualize the interference elements of design drawings, however, it cannot suggest a solution to solve the interference status. And 4D CAD tool in the construction stage can simulate the appearance of each activity by construction schedule, however, it cannot suggest an optimized schedule plan considering specified schedule condition of the project. Recently, many organizations need BIM solutions that can improve the work status beyond the level of simple visual information from BIM system. Active BIM system can provide the solutions to the project manager. This study suggests active BIM functions for the solutions and attempts to develop a 4D CAD engine to validate the usability of the functions.

• Journal of Biomedical Engineering Research
• /
• v.18 no.4
• /
• pp.397-407
• /
• 1997

In this paper, we present a signal analysis environment with visual programming capability, which is called Signal Analysis and Visualization Environment( SAVE). The system allows a user to perform visually programmed analysis of signals and visualize the results. The visualization facility enables the user to compare original signals with processed ones arid also to display signals overlaid synchronously with the events extracted from the signals. The SAVE system has an extensible architecture: each signal processing algorithm is implemented as a separate building block object module, which can be freely added or removed from the SAVE system without any code modification. We describe the overall structure of the SAVE system and the building block objects, which provide the extensibility in collaboration with together. We illustrate some test runs in order to five a taste of how to use and where to use the system.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.9
• /
• pp.1703-1710
• /
• 2017

This paper propose a 3D point clouds (depth) security technique for digital holographic display service. Image contents encryption is a method to provide only authorized right owners with the original image information by encrypting the entire image or a part of the image. The proposed method detected an edge from a depth and performed quad tree decomposition, and then performed encryption. And encrypts the most significant block among the divided blocks. The encryption effect was evaluated numerically and visually. The experimental results showed that encrypting only 0.43% of the entire data was enough to hide the constants of the original depth. By analyzing the encryption amount and the visual characteristics, we verified a relationship between the threshold for detecting an edge-map. As the threshold for detecting an edge increased, the encryption ratio decreased with respect to the encryption amount.