• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.10a
• /
• pp.203-205
• /
• 2010

파노라마 영상을 재구성하는 기존의 방법은 Labeling을 이용하여 객체를 비교한 후에 결합시키는 방법을 적용하였으나 시간이 많이 소요되고 각각의 이미지를 Labeling하는 과정에서 개체 간의 불일치가 발생하여 정확히 영상을 결합할 수 없는 경우가 발생한다. 따라서 본 논문에서는 처리 속도 개선을 위하여 전체 이미지의 1/3만 Labeling한 후에 객체 간을 비교하여 결함시킨다. 그리고 각도가 틀린 경우에는 특징점을 찾아내는 SURF 알고리즘을 적용하여 각각의 이미지에서 Labeling한 사각형의 4개의 포인터에 대해 1개의 중심점을 구하여 Homography를 이용하여 2개의 영상을 자연스럽게 정합한다. 본 논문에서 제안한 파노라마 영상 재구성 방법의 성능을 평가하기 위하여 다양한 이미지를 대상으로 실험한 결과, 기존의 방법보다 영상을 재구성하는데 효과적인 것을 확인하였다. 그리고 처리 속도 측면에서도 개선되었다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2011.04a
• /
• pp.382-383
• /
• 2011

초고전압 투과전자현미경으로부터 생산된 2D 이미지들에는 고전압(1250 kV)의 사용으로 인한 다양한 노이즈가 발생한다. 따라서 2D 이미지로부터 3D tomogram으로 재구성시 선명도 향상을 위하여 2D 이미지의 노이즈 제거 과정은 필수적이다. 본 연구에서는 band-pass filtering 기법을 활용하여 노이즈를 상당 부분 제거하였고, 필터링된 이미지로부터 3D tomogram으로 재구성한 경우 band-pass filtering의 효과가 2D 이미지에서 뿐만아니라 3D tomogram으로 재구성 했을 경우에 어떤 대역의 filter radius를 적용해야 더욱 효과가 크다는 사실을 확인하였다.

• Progress in Medical Physics
• /
• v.20 no.2
• /
• pp.62-71
• /
• 2009

Recently, optical coherence tomography (OCT) has demonstrated considerable promise for the noninvasive assessment of biological tissues. However, OCT images difficult to analyze due to speckle noise. In this paper, we tested various image processing techniques for speckle removal of human and rabbit cartilage OCT images. Also, we distinguished the images which get with methods of image segmentation for OCT images, and found the most suitable method for segmenting an image. And, we selected image segmentation suitable for OCT before image reconstruction. OCT was a weak point to system design and image processing. It was a limit owing to measure small a distance and depth size. So, good edge matching algorithms are important for image reconstruction. This paper presents such an algorithm, the chamfer matching algorithm. It is made of background for 3D image reconstruction. The purpose of this paper is to describe good image processing techniques for speckle removal, image segmentation, and the 3D reconstruction of cartilage OCT images.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2007.11a
• /
• pp.690-692
• /
• 2007

기존의 2 차원 이미지를 통한 세포 분석은 단지 세포의 단면만을 볼 수 있기 때문에 정확한 구조를 파악하기 힘들다. 본 논문에서는 그리드 기술을 이용하여 2 차원 이미지들을 세포 구조에 대한 더욱 정확한 이해 및 연구 능률의 향상을 도모할 수 있는 3 차원 이미지로 재구성하는 시스템을 개발하였다. 이 시스템은 고성능 이미지 처리를 위해서 계산 그리드를 이용하며, 화질 개선을 위한 전처리 기술, 자동 영상 정렬 기술, 효과적인 삼차원 재구성 기술과 같은 다양한 이미지 처리 알고리즘 및 preStageIn, BgUpload, delegated preprocessing 등과 같은 데이터 전송 최적화 기술 등을 제공한다. 또한, 다양한 이미지 뷰어 기능 및 DirectX 를 이용한 3 차원 렌더링 기능을 제공한다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.23 no.1
• /
• pp.84-89
• /
• 2019

JPEG is a most widely used standard image compression technology. This research introduces the JPEG image compression algorithm and describes each step in the compression and decompression. Image compression is the application of data compression on digital images. The DCT (discrete cosine transform) is a technique for converting a time domain to a frequency domain. First, the image is divided into 8 by 8 pixel blocks. Second, working from top to bottom left to right, the DCT is applied to each block. Third, each block is compressed through quantization. Fourth, the matrix of compressed blocks that make up the image is stored in a greatly reduced amount of space. Finally if desired, the image is reconstructed through decompression, a process using IDCT (inverse discrete cosine transform). The purpose of this research is to review all the processes of image compression / decompression using the discrete cosine transform method.

• Korean journal of communication and information
• /
• v.34
• /
• pp.244-274
• /
• 2006

To explore the social construction of the concept of leadership, image of media mogul depicted in the popular business newspaper, the Wall Street Journal, was analyzed. Then, the reconstructed image of the CEO was compared with the firm's stock price change to see their relationship, if any. This paper focused on the case of Steve Case (previous chairman of AOL Time Warner), who was the leader of the world largest media company. The period for the analysis was three years and five months from his inauguration(January 2000) to the resignation(May 2003). In general, CEO of a firm represents the firm itself. Thus, the image of the CEO is highly transcends to the image of the firm as well. Consequently, the image of CEO might have an impact on the firm's performance. Since business newspaper works as one of the most important information intermediaries in the stock market, the image of CEO constructed in the newspaper might be a critical indicator for the investors. The results revealed that media coverage of Steve Case was commensurate with the financial performance, particularly stock price change of the AOL Time Warner.

• Journal of the Korean Society for information Management
• /
• v.27 no.2
• /
• pp.37-60
• /
• 2010

The purpose of this study is to investigate image search query reformulation patterns in relation to image attribute categories. A total of 592 sessions and 2,445 queries from the Excite Web search engine log data were analyzed by utilizing Batley's visual information types and two facets and seven sub-facets of query reformulation patterns. The results of this study are organized with two folds: query reformulation and categorical transition. As the most dominant categories of queries are specific and general/nameable, this tendency stays over various search stages. From the perspective of reformulation patterns, while the Parallel movement is the most dominant, there are slight differences depending on initial or preceding query categories. In examining categorical transitions, it was found that 60-80% of search queries were reformulated within the same categories of image attributes. These findings may be applied to practice and implementation of image retrieval systems in terms of assisting users' query term selection and effective thesauri development.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.44 no.1
• /
• pp.108-114
• /
• 2007

This paper presented an image reconstruction method based on the original capsule endoscopy photos yielding a 2-D image for faster diagnosis proposes. The proposed method constructed a 3-D intestine model using the massive images obtained from the capsule endoscope. It merged all images and completed a 3-D model of an intestine. This 3-D model was reformed as a 2-D plane image showing the inner side of the entire intestine. The proposed image composition was evaluated by the 3-D simulator, OpenGL. This approach was demonstrated successfully. A physician can find the location of a disease at a glance because the composite image provided an easy-to-understand view to show the patient's intestine and thereby shorten diagnosis time.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.18 no.2
• /
• pp.117-123
• /
• 2018

In this study, we suggest a fast image reconstruction scheme using Poisson equation from image gradient domain. In this approach, using the Poisson equation, a guided vector field is created by employing source and target images within a selected region at the first step. Next, the guided vector is used in generating the result image. We analyze the problem of reconstructing a two-dimensional function that approximates a set of desired gradients and a data term. The joined data and gradients are able to work like modifying the image gradients while staying close to the original image. Starting with this formulation, we have a screened Poisson equation known in physics. This equation leads to an efficient solution to the problem in FFT domain. It represents the spatial filters that solve the two-dimensional screened Poisson model and shows gradient scaling to be a well-defined sharpen filter that generalizes Laplace sharpening. We demonstrate the results using a discrete cosine transformation based this Poisson model.

• The KIPS Transactions:PartB
• /
• v.13B no.3 s.106
• /
• pp.231-238
• /
• 2006

In this paper, the method to make lossless image compression that holds considerable part of total volume of mobile game has been proposed. To increase the compression rate, we compress the image by Deflate algorithm defined in RFC 1951 after reorganize it at preprocessing stage before conducting actual compression. At the stage of preprocessing, we obtained the size of a dictionary based on the information of image which is the feature of Dictionary-Based Coding, and increased the better compression rate than compressing in a general manner using in a way of restructuring image by pixel packing method and DPCM prediction technique. It has shown that the method increased 9.7% of compression rate compare with existing mobile image format, after conducting the test of compression rate applying the suggested compression method into various mobile games.