• Title/Summary/Keyword: Shading Algorithm

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Shape from Shading using the Hierarchical basis Function and Multiresolution Images (계층적 기저함수와 다해상도 영상을 이용한 영사응로부터 물체의 형상복구)

  • 이승배;이상욱;최종수
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.29B no.11
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    • pp.73-84
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    • 1992
  • In this paper, an algorithm for recovering the 3-D shape from a single shaded image is proposed. In the proposed algorithm, by using the relation between the height and surface gradient (p, q), a set of linear equations is derived from the linearized reflectance function. Then the 3-D surface is recovered by employing the conjugate gradient technique. In order to improve the convergence speed of the solution, we also employ the hierarchical basis function and multiresolution images in the algorithm. A method for determining the regularization parameter, which is determined by trial and error in the conventional approach, is also introduced. In addition, the proposed algorithm attempts to recover the 3-D surface without requiring the boundary conditions, making it suitable for a real-time implementation. Simulation results for real image as well as synthetic image are provided to demonstrate the performance of the proposed algorithm.

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A Novel Graduation Algorithm in Image Mosaic

  • Luo, Wenfei;Li, Yan;Wang, Xiaoming
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.1316-1318
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    • 2003
  • The Bernstein polynomial is one of the classic algorithms of panoramic images mosaic for shading into process applying in Virtual Reality modeling. Nevertheless, it is proven that the algorithm has its own limitation and weakness in applications. This paper was given the improved algorithm using Sinusoidal function for image mosaic. In order to put the new algorithm into image processing software as a flexible and general tool, it was further developed an extension for graduation image fusion and multi-images mosaic.

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An Implementation of 3D Graphic Accelerator for Phong Shading (퐁 음영법을 위한 3차원 그래픽 가속기의 구현)

  • Lee, Hyung;Park, Youn-Ok;Park, Jong-Won
    • Journal of Korea Multimedia Society
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    • v.3 no.5
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    • pp.526-534
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    • 2000
  • There have been many researches on the 3D graphic accelerator for high speed by needs of CAD/CAM,3D modeling, virtual reality or medical image. In this paper, an SIMD processor architecture for 3D graphic accelerator is proposed in order to improve the processing time of the 3D graphics, and a parallel Phong shading algorithm is presented to estimate performance of the proposed architecture. The proposed SIMD processor architecture for 3D graphic accelerator consists of PCI local bus interface, 16 Processing Elements (PE's), and Park's multi-access memory system (NAMS) that has 17 memory modules. A serial algorithm for Phong shading is modified for the architecture and the main key is to divide a polygon into $4\times{4}$ squares. And, for processing a square, 4 PE's are regarded as a PE Grou logically. Since MAMS can support block access type with interval 1, it is possible that 4 PE Groups process a square at a time. In consequence, 16 pixels are processed simultaneously. The proposed SIMD processor architecture is simulated by CADENCE Verilog-XL that is a package for the hardware simulation. With the same simulated results as that of the serial algorithm, the speed enhancement by the parallel algorithm to the serial one is 5.68.

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Using a computer color image automatic detection algorithm for gastric cancer (컴퓨터 컬러 영상을 이용한 위암 자동검출 알고리즘)

  • Han, Hyun-Ji;Kim, Young-Mok;Lee, Ki-Young;Lee, Sang-Sik
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.4 no.4
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    • pp.250-257
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    • 2011
  • This experiment present the automatic detection algorithm of gastric cancer that take second place among all cancers. If an inflammation and a cancer are not examined carefully, early ones have difficulty in being diagnosed as illnesses than advanced ones. For diagnosis of gastric cancer, and progressing cancer in this study, present 4 algorithm. research team extracted an abnormal part in stomach through the endoscope image. At first, decide to use shading technique or not in each endoscope image for study. it make easy distinguish to whether tumor is existing or not by putting shading technique in or eliminate it by the color. Second. By passing image subjoin shading technique to erosion filter, eliminate noise and make give attention to diagnose. Third. Analyzing out a line and fillet graph from image adding surface shade and detect RED value according to degree of symptoms. Fourth. By suggesting this algorithm, that making each patient's endscope image into subdivision graph including RED graph value, afterward revers the color, revealing the position of tumor, this study desire to help to diagnosing gastric, other cancer and inflammation.

A Real-Time Rendering Algorithm of Large-Scale Point Clouds or Polygon Meshes Using GLSL (대규모 점군 및 폴리곤 모델의 GLSL 기반 실시간 렌더링 알고리즘)

  • Park, Sangkun
    • Korean Journal of Computational Design and Engineering
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    • v.19 no.3
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    • pp.294-304
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    • 2014
  • This paper presents a real-time rendering algorithm of large-scale geometric data using GLSL (OpenGL shading language). It details the VAO (vertex array object) and VBO(vertex buffer object) to be used for up-loading the large-scale point clouds and polygon meshes to a graphic video memory, and describes the shader program composed by a vertex shader and a fragment shader, which manipulates those large-scale data to be rendered by GPU. In addition, we explain the global rendering procedure that creates and runs the shader program with the VAO and VBO. Finally, a rendering performance will be measured with application examples, from which it will be demonstrated that the proposed algorithm enables a real-time rendering of large amount of geometric data, almost impossible to carry out by previous techniques.

3-D Graphics Simulators : SOFTGRA and RACA (3차원 그래픽스 시뮬레이터 : SOFTGRA와 RACA)

  • Eo, Kil-Su;Choi, Hun-Kyu;Kyung, Chong-Min
    • Proceedings of the KIEE Conference
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    • 1987.07b
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    • pp.1528-1531
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    • 1987
  • Two graphics simulators, SOFTGRA and RACA, have been developed. The SOFTGRA has been implemented by the scan line algorithm using 2 shading models with multi-light sources. The RACA is a ray casting simulator which produces shadowed images with realism. Above two simulators run on Sun micro system and MV10000 and produce image data which are transfered into IBM AT with Metheus' Omega graphics board and drawn there.

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A Study on the Installation Angle of the Marine Solar Power Generation System (해상용 태양광 발전 시스템의 설치 각도에 관한 연구)

  • Oh, Jin-Seok;Jang, Jae-Hee
    • Journal of Navigation and Port Research
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    • v.42 no.3
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    • pp.167-176
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    • 2018
  • A solar power generation system on single point moored offshore plant has independent power system In order to satisfy the maritime environment and account for the number of sunless days, it is important to supply stable electric power to the systems. For these reasons, solar panels are installed in multiple directions. However, a partial shading effect occurs because the amount of light incident on each panel is different. The generated power by the solar generation system installed on land is affected by the latitude, then it is installed at an angle of 30 to $45^{\circ}$. in the case of Korea. In the case of a solar power generation system installed in a mooring type of marine plant, there is a possibility that the maximum power point is outside of the controllable range due to the partial shading effect. Therefore, a power generation loss occurs. By reducing the light amount difference between both panels, the maximum power point can exist in a range where the MPPT algorithm can track the power. The purpose is so the power generation efficiency can be further increased. In this paper, simulation results show that the highest power generation efficiency is obtained at an installation angle of $20^{\circ}$.

Diagnosis Method of Output Power Lowering of PV System by Using Kalman Filter Algorithm (Kalman Filter 알고리즘을 이용한 태양광 발전 시스템의 출력저하 진단법)

  • Kang, Byung-Kwan;Kim, Seung-Tak;Lee, Hyun-Gu;Bae, Sun-Ho;Park, Jung-Wook
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.8
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    • pp.1537-1546
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    • 2011
  • The photovoltaic(PV) generation system have recently become widely used to solve the environmental problems and running out of fossil fuels. However, the study on maintenance is inadequate for PV system. This paper proposes the novel diagnosis method of output power decline to maintain the normal output performance of PV array. The diagnosis method used the proportional relation of irradiation-output current(S-I) of PV array at maximum power point(MPP). And, first order polynomial using the relation is proposed to easily apply PV system. To estimate the relation in case of separation of PV array producer and diagnosis system producer. Kalman Filter algorithm is also proposed at 30.2kW grid-connected PV system. Then, the performance of diagnosis method is evaluated using the hardware tests as well as the simulation.

Real-Time Motion Blur Using Triangular Motion Paths

  • Hong, MinhPhuoc;Oh, Kyoungsu
    • Journal of Information Processing Systems
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    • v.13 no.4
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    • pp.818-833
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    • 2017
  • This paper introduces a new algorithm that renders motion blur using triangular motion paths. A triangle occupies a set of pixels when moving from a position in the start of a frame to another position in the end of a frame. This is a motion path of a moving triangle. For a given pixel, we use a motion path of each moving triangle to find a range of time that this moving triangle is visible to the camera. Then, we sort visible time ranges in the depth-time dimensions and use bitwise operations to solve the occlusion problem. Thereafter, we compute an average color of each moving triangle based on its visible time range. Finally, we accumulate an average color of each moving triangle in the front-to-back order to produce the final pixel color. Thus, our algorithm performs shading after the visibility test and renders motion blur in real time.

IMToon: Image-based Cartoon Authoring System using Image Processing (IMToon: 영상처리를 활용한 영상기반 카툰 저작 시스템)

  • Seo, Banseok;Kim, Jinmo
    • 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.