• 한국전문물리치료학회지
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• 제13권1호
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• pp.47-53
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• 2006

Since ultrasound has different reflections depending on components of organization, analysis of ultrasound images of skeletal muscle can offer both quantitative and qualitative reports as concerns skeletal muscle structure. This study is focused on the ultrasound method for evaluating the structural characteristics of skeletal muscle and also conducted to examine its practicality. After obtaining images of the elbow flexors from an ultrasound image device with 88 normal subjects whose ages were between twenty and seventy years old (44 men and 44 women), muscular density and white area index (WAI) which indicated structural characteristics of skeletal muscle were analyzed with gray scale analysis. The study examined correlations between subject's age and items which obtained from measuring ultrasound images and the differences in relations to sex and age. Muscular density and WAI had a high correlation with age and were significantly increased in men and women with greater age. The quantitative evaluation method of skeletal muscle structure which analyzed the ultrasound images has high practicality because it is a non-invasive method which complements physical therapy diagnosis and research methods and promotes functionality evaluation.

• 대한한의진단학회지
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• 제17권3호
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• pp.225-232
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• 2013

Objectives The aim of this study is to design a part in contact with the face of computerized tongue diagnosis system (CTDS), so that external light is effectively shielded even if the facial appearance and degree of protrusion differ when a patient opens or closes his/her jaws. Methods Each of the 4 researchers manually produced clay models of the part in contact with the face of CTDS. Shielding and contact feeling of the clay models were evaluated by 20 assessors. Based on the evaluation, we selected the appropriate model and produced the final silicon model. Then we evaluated the performance of the shielding of the completed silicon model. We took tongue pictures of 60 participants with a CTDS applying the silicon model in condition with external light and without it. The color values in RGB color model and gray scale of the tongue pictures in condition with external light were compared with those without external light. Results There was no significant difference between the color values of the picture taken in condition with external light and those without external light. Conclusions We concluded that the produced part in contact with the face of CTDS can effectively block out the external light.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1999년도 KOBA 방송기술 워크샵 KOBA Broadcasting Technology Workshop
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• pp.83-88
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• 1999

In this paper, a novel gray-scale lossless image coder combining context-based minimum mean squared error (MMSE) prediction and entropy coding is proposed. To obtain context of prediction, this paper first defines directional difference according to sharpness of edge and gradients of localities of image data. Classification of 4 directional differences forms“geometry context”model which characterizes two-dimensional general image behaviors such as directional edge region, smooth region or texture. Based on this context model, adaptive DPCM prediction coefficients are calculated in MMSE sense and the prediction is performed. The MMSE method on context-by-context basis is more in accord with minimum entropy condition, which is one of the major objectives of the predictive coding. In entropy coding stage, context modeling method also gives useful performance. To reduce the statistical redundancy of the residual image, many contexts are preset to take full advantage of conditional probability in entropy coding and merged into small number of context in efficient way for complexity reduction. The proposed lossless coding scheme slightly outperforms the CALIC, which is the state-of-the-art, in compression ratio.

• Journal of Electrical Engineering and Technology
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• 제13권3호
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• pp.1383-1391
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• 2018

A new nonlinear filtering algorithm for effectively denoising images corrupted by the random-valued impulse noise, called dual sliding statistics switching median (DSSSM) filter is presented in this paper. The proposed DSSSM filter is made up of two subunits; i.e. Impulse noise detection and noise filtering. Initially, the impulse noise detection stage of DSSSM algorithm begins by processing the statistics of a localized detection window in sorted order and non-sorted order, simultaneously. Next, the median of absolute difference (MAD) obtained from both sorted statistics and non-sorted statistics will be further processed in order to classify any possible noise pixels. Subsequently, the filtering stage will replace the detected noise pixels with the estimated median value of the surrounding pixels. In addition, fuzzy based local information is used in the filtering stage to help the filter preserves the edges and details. Extensive simulations results conducted on gray scale images indicate that the DSSSM filter performs significantly better than a number of well-known impulse noise filters existing in literature in terms of noise suppression and detail preservation; with as much as 30% impulse noise corruption rate. Finally, this DSSSM filter is algorithmically simple and suitable to be implemented for electronic imaging products.

• 한국정보통신학회논문지
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• 제6권5호
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• pp.789-795
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• 2002

컬러 이미지는 Gray Scale 이미지와는 달리 3가지 채널의 조합으로 이루어지고 방대한 정보량 때문에 효과적인 이미지 분할이 어렵다. 본 논문에서는 범용성 있는 Color Morphological Pyramids(CMP)구조를 제안하고, 그를 이용한 이미지 분할을 보인다. 이미지 피라미드 구조는 최초 이미지의 반복적인 필터링과 샘플링에 의해 면적비가 $2^{\int}({\int}=1,2,....,N)$이 되는 순차적 이미지 계열이다. 본 방법에서는 CMP를 이용하여 RGB, HSI, CMY 등의 컬러 공간에서 연속적인 필터링 처리로 불필요한 크기의 물체 및 잡음을 제거하고, 다운샘플링과정으로 해상도를 낮춰준다. 생성된 CMP에서 인접 레벨 이미지간에는 이웃한 픽셀 벡터간의 상대거리를 이용한 연결식을 사용하여 새 레벨의 이미지를 생성한 후 이를 이미지 분할한다. 이미지 분할실험을 통하여 본 방법의 유효성을 검증한다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 추계학술대회
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• pp.162-165
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• 2017

제안 논문은 x-ray 입력영상에서 관심부위 영역을 추출해 참조이미지와 비교하는 경우가 발생한다. x-ray영상의 모양은 같지만 대상의 크기나 방향 및 위치가 서로 다르게 촬영되어 나타나게 된다. 이와 같이 동일 대상에 대해 서로 다른 영상이 입력될 경우 영상의 유사도 측정법을 이용해 명암의 발기 차이를 측정한다. 또한 거리 측정은 x-ray 데이터의 벡터좌표(x,y,z)를 가지고 두 점간의 거리를 계산한다. 제안 방식은 기존 방식에 비해 관심영역 추출의 정확도 향상과 참조이미지 매칭 수행시간이 효율적임을 실험을 통해 증명하였다.

• 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.

• 정보처리학회논문지D
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• 제17D권6호
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• pp.463-470
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• 2010

본 논문에서는 DCT 데이터에서 영상 데이터로의 해독 및 이진화 과정을 생략하고 컬러 영상의 DCT 관련 원자료를 사용하는 방법에 기반을 둔 매우 빠르고 안정적인 문자열 구간 분리 모형을 제안하였다. DCT 블록에 저장된 DC 및 3개의 주요 AC 변수들을 조합하여 축소된 저해상도 회색 영상을 만들고 횡렬 및 종렬 투영법을 통해 얻어진 픽셀 값의 히스토그램을 분석하여 문자 열 구간 사이에 존재하는 백색의 띠 공간을 찾아내었다. 이 과정 중 탐색되지 않은 문자 열 구간은 마코프 모델을 사용하여 숨겨진 주기를 찾아내어 복원하였다. 본 논문에 실험 결과를 제시하였으며 기존의 방법보다 약 40 - 100배 빠른 방법임을 입증하였다.

• 융합정보논문지
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• 제7권2호
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• pp.77-82
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• 2017

본 논문은 차량영상을 입력영상으로 받아 차량의 종류를 인식하는 보안 알고리즘을 연구한다. 차량 인식 보안 알고리즘은 영상입력, 배경제거, 에지영역 추출, 전처리(이진화), 차량인식 등의 5가지 핵심부분으로 구성된다. 그러므로 차량 종류 인식 보안 알고리즘의 최종 인식율은 각 단계의 역할 및 기능에 직간접적인 영향을 받는다. 영상을 그레이 스케일 이미지로 입력시킨 후 배경을 제거하고, 에지영역만 추출한 후 이진화를 거친다. 외곽선을 또렷하게 해주기 위한 전처리 과정을 거친 후 차량의 높이와 넓이의 비율을 통해 차량의 종류를 대형차, 승용차, 오토바이의 3가지 범주로 나누게 했다.

• Current Optics and Photonics
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• 제5권6호
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• pp.686-698
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• 2021

A camouflaged encryption scheme based on Hadamard matrix and ghost imaging is proposed. In the process of the encryption, an orthogonal matrix is used as the projection pattern of ghost imaging to improve the definition of the reconstructed images. The ciphertext of the secret image is constrained to the camouflaged image. The key of the camouflaged image is obtained by the method of sparse decomposition by principal component orthogonal basis and the constrained ciphertext. The information of the secret image is hidden into the information of the camouflaged image which can improve the security of the system. In the decryption process, the authorized user needs to extract the key of the secret image according to the obtained random sequences. The real encrypted information can be obtained. Otherwise, the obtained image is the camouflaged image. In order to verify the feasibility, security and robustness of the encryption system, binary images and gray-scale images are selected for simulation and experiment. The results show that the proposed encryption system simplifies the calculation process, and also improves the definition of the reconstructed images and the security of the encryption system.