• 한국광학회지
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• 제20권1호
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• pp.23-28
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• 2009

본 논문에서는 대면적 리소그래피를 위하여 홀로그램 영상을 연결하여 기록 물질에 저장하고 이를 마스크로 이용하는 노광 방법을 제안하고 구현하였으며, 홀로그램 영상을 재생하는 과정에서 발생되는 영상 연결 부분에서의 간섭 무늬를 제거하였다. 연결하고자 하는 영상은 DMD(digital micro-mirror device)로 표시하였으며, DMD 영상은 축소 광학계를 통하여 기록 물질에 저장되었다. 기록 물질은 전동 스테이지로 이동되도록 하여, DMD로 표시되는 영상이 기록 물질에 연속적으로 저장되도록 하였다. 이러한 방법으로 저장되는 연결된 영상은 재생광에 의하여 노광에 사용되는데, 재생광의 간섭성에 의하여 연결부분에 간섭무늬가 발생된다. 간섭무늬는 노이즈로 작용하는데, 다중 노광에 의한 홀로그램 영상의 기록과 재생을 이용하여 이를 제거하였다. 본 논문에서는 DMD와 전동 스테이지를 이용하여 영상을 연결하여 기록하고, 다중 노광에 의한 영상 기록 방법을 이용하여, 간섭 무늬가 제거된 연결된 영상을 구현하고 이를 리소그래피에 적용하였다.

• 방송공학회논문지
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• 제24권5호
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• pp.775-784
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• 2019

영상 스티칭은 다수의 영상을 합성하여 카메라의 좁은 시야각(Field of View) 문제를 해결하는 기술이다. 최근 동영상 기반 Panorama, Super Resolution, 360 VR(Virtual Reality) 등의 콘텐츠 사용이 증가함에 따라, 보다 빠르고 정확한 영상 스티칭 기술의 필요성이 커지고 있다. 또한, 지금까지 필요 성능을 만족시키기 위해 많은 알고리즘이 제안되고 있지만, 정확성을 측정하는 객관적 평가 방법은 표준화되지 않고 있다. 최근에서야 PSNR(Peak signal-to-noise ratio)과 SSIM(Structural similarity index method) 측정값을 제시하는 방법이 주를 이루고 있지만, 본 논문에서는 PSNR과 SSIM 측정 방식의 문제점을 밝히고, 해당 방법의 한계점을 극복하여 기하적 유사성과 광도 측정 정보를 포괄하는 지역 차분 픽셀 평가(LDPM: Local differential pixel mean)방법을 제안한다. 또한, 본 논문에서 제안하는 LDPM(Local differential pixel mean) 평가 방식을 테스트 영상을 통해 증명하고 SSIM과 비교를 통해 해당 평가 방법의 이점을 밝힌다.

• 대한방사선기술학회지:방사선기술과학
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• 제43권5호
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• pp.331-336
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• 2020

In this study, we would like to examine the effect of the location of the magnification marker and the change in the stitching range on the magnification marker and the expansion of the anatomical structure in the examination of femoral stitching radiation using the stitching technique, and to find out the usability of the femoral stitching radiation examination in the preoperative examination for THRA. The measured values measured by 5 researchers were summed and presented through descriptive statistics. When the position of the magnification marker was changed, the average value of the measured value was in the range of 113.54 to 113.90 mm. The anatomical structures of the femur were measured in the range of 57.24 to 57.78 mm, 27.20 to 27.56 mm, and 70.11 to 70.81 mm, respectively. This showed a similar deviation from the expansion rate of previous related papers using markers. Therefore, it is considered that femoral stitching X-ray examination using magnification markers can be used for preoperative examination for THRA.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권3호
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• pp.459-470
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• 2013

The discovery of nearest neighbors, without training in advance, has many applications, such as the formation of mosaic images, image matching, image retrieval and image stitching. When the quantity of data is huge and the number of dimensions is high, the efficient identification of a nearest neighbor (NN) is very important. This study proposes a variation of the KD-tree - the arbitrary KD-tree (KDA) - which is constructed without the need to evaluate variances. Multiple KDAs can be constructed efficiently and possess independent tree structures, when the amount of data is large. Upon testing, using extended synthetic databases and real-world SIFT data, this study concludes that the KDA method increases computational efficiency and produces satisfactory accuracy, when solving NN problems.

• 방송공학회논문지
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• 제25권6호
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• pp.1004-1012
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• 2020

본 논문은 실시간 고해상도 비디오 스티칭을 위한 새로운 콘텐츠 보존 시접선 추정 알고리즘을 제안한다. 시접선 추정은 영상 스티칭 후 중첩 영역에서의 시각적 왜곡을 최소화하기 위한 요소 기술 중 하나이다. 기존 시접선 추정 알고리즘들은 요구되는 연산량과 메모리 사용량이 높은 최적화 알고리즘에 기반을 두고 있음에도 불구하고, 추정된 시접선이 객체를 피하지 못해 객체를 자르거나 반복하는 현상을 유발한다. 또한, 프레임 간의 추정된 시접선의 시간적 일관성이 부족하여 불필요한 잦은 변동이 발생한다. 따라서, 본 논문에서는 직선의 시접선을 활용하여 효율적이고 시간적 일관성이 있으며, 심층신경망 기반 객체 세그먼테이션 알고리즘을 활용하여 객체를 피하여 시접선을 형성하는 시접선 추정 알고리즘을 제안하고자 한다. 고해상도 360° 다중 시점 동영상을 사용한 실험을 통해 제안하는 알고리즘이 기존 알고리즘보다 짧은 시간에 시각적으로 유사한 360VR 동영상을 생성하는 시접선을 추정함을 확인하였다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 추계학술발표대회 논문집
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• pp.31-34
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• 2005

For the damage tolerance improvement of conventional laminated composites, stitching process has been utilized for providing through-thickness reinforcements. 2D prefonl1S were stacked with S-2 glass plain weave, and 3D preforms were fabricated using the stitching process. For the matrix system, epoxy and phenol resins were considered. To examine the damage resistance performance the low velocity drop weight impact test has been carried out, and the impact damage was examined by scanning image. CAI (Compressive After Ih1paet) tests were also conducted to evaluate residual compressive strength. Compared with 2D epoxy composites, 2D phenol composites showed drastic reduction in the compressive strength prior to impact because of the higher contents of voids. The damage area of 2D phenol composites were also larger than that of 2D epoxy composites. However, by introducing the stitching, the damage area of 3D phenol composites was reduced by 60%, while the CAI strength improvement was negligible.

• 한국생활과학회지
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• 제13권1호
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• pp.145-152
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• 2004

The purpose of this study was to find out the traditional decoration techniques in the Korean costume. Both quantitative and qualitative research methods were used to collect and investigated the traditional decoration techniques used in the related literatures and museum catalogues. The results were as follows. The broad and back stitching are fundamental stitching, which used to Nubi and Keki. Top stitching applied broadly to the Korean costume, for example, Jergori, Wonsam, Jeonbok, Beosun, Bojagj and so on. The expression techniques for top stitching were one, two or three stitches. When the top stitching was used as colorful stitches, they were more decorative. The Zatmulim was used for the decorative effect on the seam line because it was triangular shaped and became more effective by changing the rotor and size. Sunmulim was used on the narrow line such as the seam lines of Gergori and Chima. The bakchi decoration was imitating a bat shape, had a meaning of bringing the goodness and gave the tiny and elaborated image. It was used to the neckline of Geogori, seam line of Chima, Pungcha Bazi and so on. Sattgi was used to attaching the bottom of two stiff fabrics adopting for Beosun, Ayam and Norigae. When it used colorful strings, the more decorative effect was added. The knot for button used the fabric instead of buttons and applied to the Cheonlik, Gergori. The aesthetic values of the traditional decoration techniques in the costume were both natural beauty and practicality with creativity.

• 한국멀티미디어학회논문지
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• 제20권7호
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• pp.979-985
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• 2017

This paper, which covers a fluorescence microscopy image of brain tumor cells, looks at drug reactions by treating different types and concentrations of drugs on a plate of $24{\times}16$ wells. Due to the limitation of the field of view, a well was taken into 9 field images, and each has an overlapping area with its neighboring fields. To analyze more precisely, image stitching is needed. The basic method is finding a similar area using normalized cross-correlation (NCC). The problem is that some overlapping areas may not have any duplicated cells that help to find the matching point. In addition, the cell objects have similar sizes and shapes, which makes distinguishing them difficult. To avoid calculating similarity between blank areas and roughly distinguishing different cells, thresholding is added. The thresholding method classifies background and cell objects based on fixed thresholds and finds the location of the first seen cell. After getting its location, NCC is used to find the best correlation point. The results are compared with a simple boundary stitched image. Our proposed method stitches images that are connected in a grid form without collision, selecting the best correlation point among areas that contain overlapping cells and ones without it.

• 방송공학회논문지
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• 제24권6호
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• pp.1096-1112
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• 2019

현재 360 VR 이미지를 만들어주는 카메라들은 상당히 고가이기에 사람들이 손쉽게 사용할 순 없는 상황이다. 이를 해결하기 위해 휴대 전화의 카메라를 이용해 100여 장의 사진을 360° 촬영을 한 후 Image stitching으로 360 VR 영상을 얻고자 한다. 기존의 장비는 한 번에 360℃ 촬영으로 VR 영상을 만들어내는 반면 휴대 전화를 이용하여 촬영할 경우 영상마다 시차가 생기게 된다. 이로 인해 움직이는 물체가 있는 경우 물체가 여러 장의 영상에서 나타나는 원하지 않는 상황이 생기게 되고 Seam이 물체를 관통하여 부자연스러운 결과 영상을 얻게 된다. 본 논문에서는 시각적으로 두드러지는 물체를 판별할 수 있는 Saliency map을 이용한 Seam finder 알고리즘을 통해 개선된 결과 영상을 얻을 수 있음을 확인했다.

• Journal of Multimedia Information System
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• 제5권2호
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• pp.131-138
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• 2018

This work describes a binary image based fast Difference of Gaussian (DoG) filter using zero-dimensional (0-d) convolution and state machine look up tables (LUTs) for image and video stitching hardware platforms. The proposed approach for using binary images to obtain DoG filtering can significantly reduce the data size compared to conventional gray scale based DoG filters, yet binary images still preserve the key features of the image such as contours, edges, and corners. Furthermore, the binary image based DoG filtering can be realized with zero-dimensional convolution and state machine LUTs which eliminates the major portion of the adder and multiplier blocks that are generally used in conventional DoG filter hardware engines. This enables fast computation time along with the data size reduction which can lead to compact and low power image and video stitching hardware blocks. The proposed DoG filter using binary images has been implemented with a FPGA (Altera DE2-115), and the results have been verified.