• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.544-547
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• 1999

This paper proposes a high-speed texture mapping algorithm and apply it for the realtime face animation. The mapping process devide into pixel correspondences, Z-buffering, and pixel value interpolation. Pixel correspondences and Z-buffering are calculated exactly through the algorithm. However, pixel values interpolation is approximated without additional calculations. The algorithm dramatically reduces the operations needed for texture mapping. Only three additions are needed in calculation of a pixel value. We simulate the 256$\times$240 pixel facial image with about 100 pixel face width. Simulation results shows that frame generation speed are about 60, 44, 21 frames/second in pentium PC 550MHz, 400MHz, 200MHz, respectively,

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.6
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• pp.1363-1368
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• 2011

This paper describes an analysis on the granular noise in pixel-to-pixel mapping-based computational integral imaging. The pixel mapping-based method provides a high-resolution reconstructed images and also its computational cost is very lower than the previous back-projection-based method. In this paper, a signal model for the pixel mapping-based method is introduced, which defines and analyzes the granular noise. Computer experiments provides the granular noise properties based on the proposed signal model. The experimental results indicates that the granular noise pattern differs from that of the back-projection based method. The results is also utilized in the pixel mapping-based method.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.11a
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• pp.295-298
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• 2006

본 논문에서는 극 좌표계에서의 벡터 표현 방식을 이용한 per-pixel displacement mapping 방법을 제시한다. per-pixel displacement mapping은 triangle mesh의 처리 방식에 상관없이 변위매핑을 수행할 수 있도록 한 것으로, 2차원 screen space로 projection 된 triangle의 각 pixel의 위치를 객체 표면 정보에 따라 displacement 해주는 방법이다. 이는 기 검증된 범프매칭 하드웨어에 약간의 하드웨어를 추가함으로써 변위매핑을 수행할 수 있도록 한 효과적인 구조이다. 제안 방식에 의해 생성된 영상과 기존 방식에 의해 생성된 영상을 비교해본 결과, 시각적으로 거의 차이가 없음을 알 수 있다.

• Proceedings of the KSRS Conference
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• 2007.03a
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• pp.251-256
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• 2007

FY-2C 위성은 2004년 10월 발사되어 동경 105도 에 서 운영 중인 중국의 정지 궤도 기상위성 이며 관측 영상은 한반도 지역을 포함하고 있다. 현재 FY-2C S-VISSR2.0[l]에 대한 Navigation 알고리즘이 공개되어 있지 않으며，Navigation을 위하여 S-VISSR2.0에 포함되어 있는 Simplified Mapping Block 정보를 사용하여야 한다. Simplified Mapping Block은 5도 간격의 정보만을 제 공하므로 관측 지 역 의 모든 좌표에 대한 Navigation 정보를 얻기 위해서는 보간볍을 사용하여야 한다. 그러나 보간법은 기준 점에서 멀어질수록 오차가 크게 나타날 수 있다. 따라서 본 논문에서는 모든 좌표에 대한 Navigation 정보를 얻을 수 있는 MTSAT Image Navigation 알고리즘을 FY-2C S-VISSR2.0에 적용하여 Simplified Mapping Block과의 차이를 분석하였다. 분석 방법은 Simplified Mapping Block과 MTSAT Image Navigation[2] 알고리즘을 5도 간격의 격자 점(위경도)에서 Column 및 Line 값 비교， Geo-location된 영상의 품질 비교，WDB2 Map Data의 Coast Line과의 비교를 수행하였다. 분석 결과 격자 점에서의 Column, Line 값은 0.5 이내의 차이 값을 나타내었다. 그리고 Geo-location된 영상 비교에서는 격자 점 주변에서 영상의 차이가 없으나 격자 점에서 멸어질수록 영상의 품질은 MTSAT Image Navigation 알고리즘으로 생성한 영상이 더 우수하였다. WDB2 Map Data의 Coast Line과의 비교에서 오차는 동일하게 발생하였으며，영상의 Column 축에 대한 오차는 평균 1.847 Pixel, 최대 6 Pixel, 최소 oPixel 이며， Line 축에 대한 오차는 평균 0.135 Pixel, 최대 4 Pixel, 최소 0 Pixel을 나타내었다.

• Korean Journal of Remote Sensing
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• v.23 no.3
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• pp.153-160
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• 2007

Forest cover density studies using high resolution satellite data and object oriented classification are limited in India. This article focuses on the potential use of QuickBird satellite data and object oriented classification in forest density mapping. In this study, the high-resolution satellite data was classified based on NDVI/pixel based and object oriented classification methods and results were compared. The QuickBird satellite data was found to be suitable in forest density mapping. Object oriented classification was superior than the NDVI/pixel based classification. The Object oriented classification method classified all the density classes of forest (dense, open, degraded and bare soil) with higher producer and user accuracies and with more kappa statistics value compared to pixel based method. The overall classification accuracy and Kappa statistics values of the object oriented classification were 83.33% and 0.77 respectively, which were higher than the pixel based classification (68%, 0.56 respectively). According to the Z statistics, the results of these two classifications were significantly different at 95% confidence level.

• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.181-182
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• 2008

In this paper, we propose a volumetric computational reconstruction method by use of smart pixel mapping technique in the computational integral imaging in order to overcome the problem of resolution degradation. The experimental results are presented to show the usefulness of our proposed technique.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.9
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• pp.3286-3301
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• 2014

Jung and Yoo proposed the first image interpolation-based reversible data hiding algorithm. Although their algorithm achieved superior interpolation results, the embedding capacity was insufficient. Lee and Huang proposed an improved algorithm to enhance the embedding capacity and the interpolation results. However, these algorithms present limitations to magnify the original image to any resolution and pixels in the boundary region of the magnified image are poorly manipulated. Furthermore, the capacity and the image quality can be improved further. This study modifies the pixel mapping scheme and adopts a bilinear interpolation to solve boundary artifacts. The modified reference pixel determination and an optimal pixel adjustment process can effectively enhance the embedding capacity and the image quality. The experimental results show our proposed algorithm achieves a higher embedding capacity under acceptable visual distortions, and can be applied to a magnified image at any resolution. Our proposed technique is feasible in reversible data hiding.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.4 no.1
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• pp.50-55
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• 2004

We propose an intgrated Gill environment system having only integer fuzzy operations in the consequent part and the defuzzification stage. In this paper, we also propose an integrated Gill environment system with 4 parallel fuzzy processing units to be operated in parallel on the classification of the sensed image data. In this, we solve the problems of taking longer times as the fuzzy real computations of [0, 1] by using the integer pixel conversion algorithm to convert lines of each fuzzy linguistic term to the closest integer pixels. This procedure is performed automatically in the GUI application program. As a Gill environment, PCI transmission, image data pre-processing, integer pixel mapping and fuzzy membership tuning are considered. This system can be operated in parallel manner for MIMO or MISO systems.

• Journal of information and communication convergence engineering
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• v.15 no.4
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• pp.256-261
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• 2017

In this paper, we propose a modified smart pixel mapping (SPM) to visualize occluded three-dimensional (3D) objects in real image fields. In integral imaging, orthoscopic real 3D images cannot be displayed because of lenslets and the converging light field from elemental images. Thus, pseudoscopic-to-orthoscopic conversion which rotates each elemental image by 180 degree, has been proposed so that the orthoscopic virtual 3D image can be displayed. However, the orthoscopic real 3D image cannot be displayed. Hence, a conventional SPM that recaptures elemental images for the orthoscopic real 3D image using virtual pinhole array has been reported. However, it has a critical limitation in that the number of pixels for each elemental image is equal to the number of elemental images. Therefore, in this paper, we propose a modified SPM that can solve this critical limitation in a conventional SPM and can also visualize the occluded objects efficiently.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.5
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• pp.2273-2286
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• 2018

This paper describes transformations between elemental image arrays and a RGBD image for three-dimensional integral imaging and transmitting systems. Two transformations are introduced and analyzed in the proposed method. Normally, a RGBD image is utilized in efficient 3D data transmission although 3D imaging and display is restricted. Thus, a pixel-to-pixel mapping is required to obtain an elemental image array from a RGBD image. However, transformations and their analysis have little attention in computational integral imaging and transmission. Thus, in this paper, we introduce two different mapping methods that are called as the forward and backward mapping methods. Also, two mappings are analyzed and compared in terms of complexity and visual quality. In addition, a special condition, named as the hole-free condition in this paper, is proposed to understand the methods analytically. To verify our analysis, we carry out experiments for test images and the results indicate that the proposed methods and their analysis work in terms of the computational cost and visual quality.