• Proceedings of the Korea Contents Association Conference
• /
• 2009.05a
• /
• pp.163-168
• /
• 2009

Since 3D gamers can control points of view and field of view freely, 3D games generate high realities and immersions. On most of 3D games, a point of view and a field of view are determined by positions and FOV(field of view) of camera. Although FOV is a simple technical factor, it leads to graphics distortion and affects immersion of the game and causes some gamers to get physical sickness. Therefore, we will suggest the instruction to operate FOVs in many 3D games by examining and analysing various rendering results with control of FOV and real cases of FOV in published games with same 3D modeling environments.

• Journal of Astronomy and Space Sciences
• /
• v.20 no.4
• /
• pp.393-402
• /
• 2003

The Multi-Spectral Camera (MSC) is the payload of KOMPSAT-2 which is designed for earth imaging in optical and near-infrared region on a sun-synchronous orbit. The telescope in the MSC is a Ritchey-Chretien type with large aperture. The telescope structure should be well stabilized and the optical alignment should be kept steady so that best images can be achieved. However, the MSC is exposed to adverse thermal environment on the orbit which can give impacts on optical performance. Solar incidence can bring non-uniform temperature rise on the telescope tube which entails unfavorable thermal distortion. Three ways of preventing the solar radiation were proposed, which were installing external mechanical shield, internal shield, and maneuvering the spacecraft. After trade-off study, internal sun shield was selected as a practical and optimal solution to minimize the effect of the solar radiation. In addition, detailed designs of the structure and sunshield were produced and analyses have been performed. The results were assessed to verify their impacts to the image quality. It was confirmed that the internal sunshield complies with the requirements and would improve image quality.

• Proceedings of the KSRS Conference
• /
• 2004.10a
• /
• pp.452-455
• /
• 2004

MSC (Multi-Spectral Camera) system is a remote sensing instrument to obtain high resolution ground image. EOS (Electro-Optic System) for MSC mainly consists of PMA (Primary Mirror Assembly), SMA (Secondary Mirror Assembly), HSTS (High Stability Telescope Structure) and DFPA (Detector Focal Plane Assembly). High performance of EOS makes it possible for MSC system to provide high resolution and high quality ground images. Temperature of the EOS needs to be controlled to be in a specific range in order not to have any thermal distortion which can cause performance degradation. It is controlled by full redundant CPU based electronics. The validity of thermistor readings can be checked because a few thermistors are installed on each control point on EOS. Various kinds of thermal control logics are used to prevent 'Single Point Failure'. Control logic has a few set of database in order not to be corrupted by SEU (Single Event Upset). Even though the thermal control logic is working automatically, it can also be monitored and controlled by ground-station operator. In this paper, various ways of thermal control logic for EOS in MSC will be presented, which include thermal control mode and logic, redundancy design and status monitoring and reporting scheme.

• Journal of Computational Design and Engineering
• /
• v.2 no.1
• /
• pp.38-46
• /
• 2015

Augmented reality based on projection, called "Spatial Augmented Reality (SAR)", is a new technology that can produce immersive contents by overlapping virtuality and real-world environment. It has been paid attention as the next generation digital contents in media art and human-computer interaction (HCI). In this paper, we present a new methodology to evaluate the product appearance design more intuitively by means of SAR technique. The proposed method first projects the high-quality rendered image considering the optical property of materials onto the mock-up of a product. We also conduct a projector-camera calibration to compensate a color distortion according to a projector, a projection surface and environment lighting. The design evaluation methodology we propose offers more flexible and intuitive evaluation environment to a designer and user (evaluator) than previous methods that are performed via a digital display. At the end of this research, we have conducted a case study for designing and evaluating appearance design of an automobile.

• Journal of the Korean Institute of Telematics and Electronics T
• /
• v.36T no.4
• /
• pp.9-16
• /
• 1999

We suggest the image recognition algorithm for automatic decision of EUT malfunction using computer vision in the radiant electromagnetic field. We monitor and analyze the EUT malfunction through the numerical value change of electro-measurement and medical instruments, or the image distortion of PC monitor. We could decide EUT malfunction by comparing the object image in the electromagnetic field with the reference image or by recognizing the numerical value change on the video camera monitor. We can show the evidence of EUT malfunction decision and reduce the possibility of malfunction in the tolerance test.

• Journal of Broadcast Engineering
• /
• v.20 no.3
• /
• pp.379-387
• /
• 2015

In recent years, copyright violations from illegal copying and distribution of e-comic contents have become an important issue. Fingerprinting techniques have been emerged to provide a fast and reliable identification method of identifying e-comic contents. When illegally scanned or camera captured comic contents are distributed, they suffer from distortions. So the fingerprint differs from the original version. This paper presents a restoration framework for correcting geometric distortions in distorted comics to improve the comic content identification.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.11 no.5
• /
• pp.65-71
• /
• 2011

Face warping techniques have been used for correcting image distortion as well as for creative purposes(e.g., morphing). Smartphone can capture an image from camera and transfer it through network. Thus, warping software which is implemented on the smartphone may be widely used in the fields of game and plastic surgery. This paper describes the design of face warping software using transformation with multiple pairs of lines and bilinear interpolation, and then shows the implementation results on the smartphone. Through many people review, this software showed real-time responsiveness and good transformation quality.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2009.01a
• /
• pp.59-62
• /
• 2009

In general, as a dynamic range of digital still camera is narrower than a real scene‘s, it is hard to represent the shadow region of scene. Thus, multi-scaled retinex algorithm is used to improve detail and local contrast of the shadow region in an image by dividing the image by its local average images through Gaussian filtering. However, if the chromatic distribution of the original image is not uniform and dominated by a certain chromaticity, the chromaticity of the local average image depends on the dominant chromaticity of original image, thereby the colors of the resulting image are shifted to a complement color to the dominant chromaticity. In this paper, a modified multi-scaled retinex method to reduce the influence of the dominant chromaticity is proposed. In multi-scaled retinex process, the local average images obtained by Gaussian filtering are divided by the average chromaticity values of the original image in order to reduce the influence of dominant chromaticity. Next, the chromaticity of illuminant is estimated in highlight region and the local average images are corrected by the estimated chromaticity of illuminant. In experiment, results show that the proposed method improved the local contrast and detail without color distortion.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.10a
• /
• pp.78-81
• /
• 2012

In this paper, we proposed the new vehicle license plates detection method which is available in a various fields, including vehicle access control, illegal parking and speeding vehicle crack down. First, we binarize an image by using difference of gaussian filter to find a sequence of numbers of plates. Second, we determine the plate region by labeling repeatedly using the morphological characteristics of the plates. Finally, we use a projective transformation for correcting the distortion that occurs because of the camera or the location of the vehicle.

• The Journal of Korea Robotics Society
• /
• v.11 no.4
• /
• pp.205-216
• /
• 2016

The localization of the robot is one of the most important factors of navigating mobile robots. The use of featured information of landmarks is one approach to estimate the location of the robot. This approach can be classified into two categories: the natural-landmark-based and artificial-landmark-based approach. Natural landmarks are suitable for any environment, but they may not be sufficient for localization in the less featured or dynamic environment. On the other hand, artificial landmarks may generate shaded areas due to space constraints. In order to improve these disadvantages, this paper presents a novel development of the localization system by using artificial and natural-landmarks-based approach on a topological map. The proposed localization system can recognize far or near landmarks without any distortion by using landmark tracking system based on top-view image transform. The camera is rotated by distance of landmark. The experiment shows a result of performing position recognition without shading section by applying the proposed system with a small number of artificial landmarks in the mobile robot.