• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.445-450
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• 2008

본 논문에서는 객체의 인식성을 높이기 위해 가상의 지역 광원을 사용한 카툰 렌더링 기법을 제안한다. 지역 광원은 각 메쉬의 기하 정보를 분석하여 배치되며 객체의 지역적인 음영 대비를 증가시켜 객체의 모양과 특정이 눈에 잘 띄도록 한다. 하지만 지역 광원을 사용한 쉐이딩 기법은 객체의 일부 영역에서 갈라지고 불연속적인 음영을 만들어 이미지의 질적 하락을 초래한다. 이러한 현상을 막기 위하여 곡률과 샐리언시의 개념을 사용하여 영역의 특성에 따라 차등적으로 지역 광원을 객체에 적용하였다. 곡률은 해당 영역의 기하적 특성을 구분하여 지역 광원에 의한 음영 대비 증감을 조정하고, 샐리언시는 영역의 중요도를 판별하여 곡률이 쉐이딩에 미치는 가중치를 조절한다.

• Journal of Korea Multimedia Society
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• v.14 no.8
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• pp.1082-1093
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• 2011

Traditional rendering of cartoon character cannot revive the feeling of concept drawings properly. In this paper, we propose capture technology to get toon shading model from the concept drawings and with this technique, we provide a new novel system to render 3D cartoon character. Benefits of this system is to cartoonize the 3D character according to saliency to emphasize the form of 3D character and further support the sketch-based user interface for artists to edit shading by post-production. For this, we generate texture automatically by RGB color sorting algorithm to analyze color distribution and rates of selected region. In the cartoon rendering process, we use saliency as a measure to determine visual importance of each area of 3d mesh and we provide a novel cartoon rendering algorithm based on the saliency of 3D mesh. For the fine adjustments of shading style, we propose a user interface that allow the artists to freely add and delete shading to a 3D model. Finally, this paper shows the usefulness of the proposed system through user evaluation.

• Journal of the Korea Computer Graphics Society
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• v.23 no.2
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• pp.11-22
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• 2017

This study proposes IMToon(IMage-based carToon) which is an image-based cartoon authoring system using an image processing algorithm. The proposed IMToon allows general users to easily and efficiently produce frames comprising cartoons based on image. The authoring system is designed largely with two functions: cartoon effector and interactive story editor. Cartoon effector automatically converts input images into a cartoon-style image, which consists of image-based cartoon shading and outline drawing steps. Image-based cartoon shading is to receive images of the desired scenes from users, separate brightness information from the color model of the input images, simplify them to a shading range of desired steps, and recreate them as cartoon-style images. Then, the final cartoon style images are created through the outline drawing step in which the outlines of the shaded images are applied through edge detection. Interactive story editor is used to enter text balloons and subtitles in a dialog structure to create one scene of the completed cartoon that delivers a story such as web-toon or comic book. In addition, the cartoon effector, which converts images into cartoon style, is expanded to videos so that it can be applied to videos as well as still images. Finally, various experiments are conducted to verify the possibility of easy and efficient production of cartoons that users want based on images with the proposed IMToon system.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.449-454
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• 2009

The human face has "expression" as an important visual factor in contrast with general objects. For this reason, cartoonists draw shadow that emphasizes facial shape and facial expression in order to convey atmosphere of scene and trait of character. This shadow should be considered when doing cartoon rendering for facial expression although it is not an physical shading. This paper proposes a cartoon rendering system for facial expression based on shading techniques of real cartoonist. First of all, we searched such techniques of cartoonist through variety of collected cartoon images and defined shadow templates according to character's facial expression to do cartoon rendering diffently. After that, we demonstrated cartoon rendering system of facial expression on the basis of survey result that effectively emphasizes facial shape and facial expression. Finally, we showed the usefulness through the user questionnaire.

• The Journal of the Korea Contents Association
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• v.11 no.8
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• pp.123-133
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• 2011

In this paper, we propose a new method for toon shading using 3D texture which renders 3d objects in a cartoon style. The conventional toon shading using 1D texture displays shading tone by computing the relative position and orientation between a light vector and surface normal. The 1D texture alone has limits to express the various tone change according to any viewing condition. Therefore Barla et. al. replaces a 1D texture with a 2D texture whose the second dimension corresponds to the view-dependent effects such as level-of-abstraction, depthof-field. The proposed scheme extends 2D texture to 3D texture by adding one dimension with the geometric information of 3D objects such as curvature, saliency, and coordinates. This approach supports two kinds of extensions for cartoon style diversification. First, we support "shape exaggeration effect" to emphasize silhouette or highlight according to the geometric information of 3D objects. Second, we further incorporate "cartoon specific effect", which is examples of screen tone and out focusing frequently appeared in cartoons. We demonstrate the effectiveness of our approach through examples that include a number of 3d objects rendered in various cartoon style.

• The Journal of the Korea Contents Association
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• v.10 no.8
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• pp.119-129
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• 2010

Recently, development of mobile service and increased demand for mobile device make mobile environment noticeable in computer graphics. Especially demand for 3D graphic services in mobile devices is steadily increased. However up to the present non-photorealistic rendering is mainly studied in desktop platform. In the result, existing research were designed for desktop computers and are not well-suited for mobile devices. Thus, there is a growing needs for processing techniques that provide the ability to render 3D non-photorealistic graphics through mobile devices. In this paper, we discuss processing techniques for non-photorealistic rendering that are especially cartoon shading and rendering in mobile devices. Through the result of this research, it is expected that silhouette edge rendering for mobile display environment and preprocessing file technique for shading. The efficiency of 3D mobile graphic service like 3D model in cartoon style is increased by using proposed preprocessing file and rendering pipeline. Our work can provide mobile cartoon rendering results and various mobile contents to users.

• Smart Media Journal
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• v.10 no.2
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• pp.30-37
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• 2021

Recently, 3D contents used in various fields have been attracting people's attention due to the development of virtual reality and augmented reality technology. In order to produce 3D contents, it is necessary to model the objects as vertices. However, high-quality modeling is time-consuming and costly. In order to convert a 2D character into a 3D model, it is necessary to express it as line drawings through feature line extraction. The extraction of consistent line drawings from 2D cartoon cartoons is difficult because the styles and techniques differ depending on the designer who produces them. Therefore, it is necessary to extract the line drawings that show the geometrical characteristics well in 2D cartoon shapes of various styles. This study proposes a method of automatically extracting line drawings. The 2D Cartoon shading image and line drawings are learned by using adversarial network model, which is artificial intelligence technology and outputs 2D cartoon artwork of various styles. Experimental results show the proposed method in this research can be obtained as a result of the line drawings representing the geometric characteristics when a 2D cartoon painting as input.

• Journal of the Korea Computer Graphics Society
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• v.14 no.4
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• pp.19-25
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• 2008

In this paper, we present new cel shading technique using local light that increases local contrast for apparent shape depiction. To convey detail and overall shape, we employ virtual local light to represent cubic effect and local shape. Moreover, we control increase of local contrast using curvature as complexity and curvature as importance to adapt depicted local shape to feature of each area. Our technique depicts shape well wherever global light is.

• The Journal of the Korea Contents Association
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• v.8 no.11
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• pp.154-161
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• 2008

Rapidly changing 3D rendering technology is expanding its fields of display fast towards Non-Photorealistic Rendering beyond Photorealistic Rendering. It is now attainable to realize conventional 2D visual animated cartoons with 3D animation technology. It is not complex to create two shades of color or more with the rendered outcomes, made by Toon-Shading, of 3D total packaging animation Maya with black outlines brought through the process of 2D animation. It the reality of 3D animation being one of the prevalent mechanisms of animated films, it is valuable for familiarized animated cartoons to be realized by the technology of 3D animation. Thus, I hope to help in many ways create more effective 3D cartoon animation production process by optimized Toon-Shading attributes method and technology in this research.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.01a
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• pp.206-207
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• 2020

본 논문에서는 웹툰에서 사용되는 대규모 군중 격투씬을 표현하기 위하여 Unity3D 엔진을 사용하는 방법에 대해 연구하였다. 웹툰에서는 대규모 군중을 표현할 때 그 작업량을 줄이고 속도를 올리기 위해 여러 가지 자동화 방법을 고려하고 있고, 빠른 피드백과 실시간 렌더링, 쉬운 조작이 가능한 게임 엔진은 이 경우에 매우 유용한 도구가 될 수 있다.