• Title/Summary/Keyword: edge-detection

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A Study on a Multiresolution Filtering Algorithm based on a Physical Model of SPECT Lesion Detectability (SPECT 이상조직 검출능 모델에 근거한 다해상도 필터링 기법 연구)

  • Kim, Jeong-Hui;Kim, Gwang-Ik
    • Journal of Biomedical Engineering Research
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    • v.19 no.6
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    • pp.551-562
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    • 1998
  • Amultiresolution filtering algorithm based on the physical SPECT lesion detachability provides and optimal solution for SPECT reconstruction problem. Related to the previous study, we estimated the SPECT lesion detection capability by m minimum detectable lesion sizes (MDLSs), and generated m reconstruction filters which are designed to maximize the smoothing effect at a fixed MDLS-dependent resolution level $\frac{MDLS}{4\sqrt{2In2}}$. The proposed multiresolution filtering algorithm used a coarse-to-fine approach for the m-level resolution filter images obtained from these m filters for a given projection image. First, the local homogeneity is determined for every pixel of the filter images, by comparing the local variance value computed in a window centered at the pixel and the mode determined from the distribution of the local variances. Based on the local homogeneity, the pixels declared as homogeneous are chosen from the filter image of the lowest resolution, and for the other pixels the same process is repeated for the higher resolution filter images. For the non-homogeneous pixels after this pixels after this repetition process ends, the pixel values of the highest resolution filter image are substituted. From the results of the simulated experiments, the proposed multiresolution filtering algorithm showed a strong smoothing effect in the homogeneous regions and a significant resolution improvement near the edge regions of the projection images, and so produced good adaptability effects in the reconstructed images.

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Evaluation of Image Quality for Diagnostic Digital Chest Image Using Ion Chamber in the Total Mastectomy (변형근치유방절제술 환자의 Ion chamber 변화에 따른 디지털 흉부 영상의 화질 평가)

  • Lee, Jin-Soo;Ko, Seong-Jin;Kang, Se-Sik;Kim, Jung-Hoon;Park, Hyong-Hu;Kim, Donghyun;Kim, Changsoo
    • The Journal of the Korea Contents Association
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    • v.13 no.3
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    • pp.204-210
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    • 2013
  • The patients who had been operated total mastectomy are different from general women in their breasts thickness due to breast surgery. As a result, digital chest image from total mastectomy patients will be different attenuation. The main objective for this study is to show that a proper Ion chamber standard combination measuring MTF which is objective basis for Digital image, when be x-ray for total mastectomy patient. We have designed the unique number that shown Left is 1, Right is 2, Center is 3 and have put the edge phantom on detector ion chamber. Lastly, we have obtained experiment images. The evaluations of all image quality have measured by 50% MTF of spatial resolution and absorption dose using Matlab(R2007a). The result showed that average exposure condition, MTF value, absorption dose for 1+3 and 2+3 combinations were 2.745 mAs, 1.925 lp/mm, 0.688 mGy. Consequently, that showed high MTF, DQE and low dose than other combinations. Therefore, a proper changes of ion chambers are able to improve image quality and to reduce radiation exposure when be X-ray for total mastectomy patients. Also, it will be possible to standard for application chamber combination and utilization on clinical detection.

3D Stereoscopic Image Generation of a 2D Medical Image (2D 의료영상의 3차원 입체영상 생성)

  • Kim, Man-Bae;Jang, Seong-Eun;Lee, Woo-Keun;Choi, Chang-Yeol
    • Journal of Broadcast Engineering
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    • v.15 no.6
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    • pp.723-730
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    • 2010
  • Recently, diverse 3D image processing technologies have been applied in industries. Among them, stereoscopic conversion is a technology to generate a stereoscopic image from a conventional 2D image. The technology can be applied to movie and broadcasting contents and the viewer can watch 3D stereoscopic contents. Further the stereoscopic conversion is required to be applied to other fields. Following such trend, the aim of this paper is to apply the stereoscopic conversion to medical fields. The medical images can deliver more detailed 3D information with a stereoscopic image compared with a 2D plane image. This paper presents a novel methodology for converting a 2D medical image into a 3D stereoscopic image. For this, mean shift segmentation, edge detection, intensity analysis, etc are utilized to generate a final depth map. From an image and the depth map, left and right images are constructed. In the experiment, the proposed method is performed on a medical image such as CT (Computed Tomograpy). The stereoscopic image displayed on a 3D monitor shows a satisfactory performance.

Adaptive Vehicle License Plate Recognition System Using Projected Plane Convolution and Decision Tree Classifier (투영면 컨벌루션과 결정트리를 이용한 상태 적응적 차량번호판 인식 시스템)

  • Lee Eung-Joo;Lee Su Hyun;Kim Sung-Jin
    • Journal of Korea Multimedia Society
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    • v.8 no.11
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    • pp.1496-1509
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    • 2005
  • In this paper, an adaptive license plate recognition system which detects and recognizes license plate at real-time by using projected plane convolution and Decision Tree Classifier is proposed. And it was tested in circumstances which presence of complex background. Generally, in expressway tollgate or gateway of parking lots, it is very difficult to detect and segment license plate because of size, entry angle and noisy problem of vehicles due to CCD camera and road environment. In the proposed algorithm, we suggested to extract license plate candidate region after going through image acquisition process with inputted real-time image, and then to compensate license size as well as gradient of vehicle with change of vehicle entry position. The proposed algorithm can exactly detect license plate using accumulated edge, projected convolution and chain code labeling method. And it also segments letter of license plate using adaptive binary method. And then, it recognizes license plate letter by applying hybrid pattern vector method. Experimental results show that the proposed algorithm can recognize the front and rear direction license plate at real-time in the presence of complex background environments. Accordingly license plate detection rate displayed $98.8\%$ and $96.5\%$ successive rate respectively. And also, from the segmented letters, it shows $97.3\%$ and $96\%$ successive recognition rate respectively.

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An Efficient Real-Time Image Reconstruction Scheme using Network m Multiple View and Multiple Cluster Environments (다시점 및 다중클러스터 환경에서 네트워크를 이용한 효율적인 실시간 영상 합성 기법)

  • You, Kang-Soo;Lim, Eun-Cheon;Sim, Chun-Bo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.11
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    • pp.2251-2259
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    • 2009
  • We propose an algorithm and system which generates 3D stereo image by composition of 2D image from 4 multiple clusters which 1 cluster was composed of 4 multiple cameras based on network. Proposed Schemes have a network-based client-server architecture for load balancing of system caused to process a large amounts of data with real-time as well as multiple cluster environments. In addition, we make use of JPEG compression and RAM disk method for better performance. Our scheme first converts input images from 4 channel, 16 cameras to binary image. And then we generate 3D stereo images after applying edge detection algorithm such as Sobel algorithm and Prewiit algorithm used to get disparities from images of 16 multiple cameras. With respect of performance results, the proposed scheme takes about 0.05 sec. to transfer image from client to server as well as 0.84 to generate 3D stereo images after composing 2D images from 16 multiple cameras. We finally confirm that our scheme is efficient to generate 3D stereo images in multiple view and multiple clusters environments with real-time.

A Prostate Segmentation of TRUS Image using Average Shape Model and SIFT Features (평균 형상 모델과 SIFT 특징을 이용한 TRUS 영상의 전립선 분할)

  • Kim, Sang Bok;Seo, Yeong Geon
    • KIPS Transactions on Software and Data Engineering
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    • v.1 no.3
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    • pp.187-194
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    • 2012
  • Prostate cancer is one of the most frequent cancers in men and is a major cause of mortality in the most of countries. In many diagnostic and treatment procedures for prostate disease, transrectal ultrasound(TRUS) images are being used because the cost is low. But, accurate detection of prostate boundaries is a challenging and difficult task due to weak prostate boundaries, speckle noises and the short range of gray levels. This paper proposes a method for automatic prostate segmentation in TRUS images using its average shape model and invariant features. This approach consists of 4 steps. First, it detects the probe position and the two straight lines connected to the probe using edge distribution. Next, it acquires 3 prostate patches which are in the middle of average model. The patches will be used to compare the features of prostate and nonprostate. Next, it compares and classifies which blocks are similar to 3 representative patches. Last, the boundaries from prior classification and the rough boundaries from first step are used to determine the segmentation. A number of experiments are conducted to validate this method and results showed that this new approach extracted the prostate boundary with less than 7.78% relative to boundary provided manually by experts.

DEVELOPMENT OF AN AMPHIBIOUS ROBOT FOR VISUAL INSPECTION OF APR1400 NPP IRWST STRAINER ASSEMBLY

  • Jang, You Hyun;Kim, Jong Seog
    • Nuclear Engineering and Technology
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    • v.46 no.3
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    • pp.439-446
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    • 2014
  • An amphibious inspection robot system (hereafter AIROS) is being developed to visually inspect the in-containment refueling storage water tank (hereafter IRWST) strainer in APR1400 instead of a human diver. Four IRWST strainers are located in the IRWST, which is filled with boric acid water. Each strainer has 108 sub-assembly strainer fin modules that should be inspected with the VT-3 method according to Reg. guide 1.82 and the operation manual. AIROS has 6 thrusters for submarine voyage and 4 legs for walking on the top of the strainer. An inverse kinematic algorithm was implemented in the robot controller for exact walking on the top of the IRWST strainer. The IRWST strainer has several top cross braces that are extruded on the top of the strainer, which can be obstacles of walking on the strainer, to maintain the frame of the strainer. Therefore, a robot leg should arrive at the position beside the top cross brace. For this reason, we used an image processing technique to find the top cross brace in the sole camera image. The sole camera image is processed to find the existence of the top cross brace using the cross edge detection algorithm in real time. A 5-DOF robot arm that has multiple camera modules for simultaneous inspection of both sides can penetrate narrow gaps. For intuitive presentation of inspection results and for management of inspection data, inspection images are stored in the control PC with camera angles and positions to synthesize and merge the images. The synthesized images are then mapped in a 3D CAD model of the IRWST strainer with the location information. An IRWST strainer mock-up was fabricated to teach the robot arm scanning and gaiting. It is important to arrive at the designated position for inserting the robot arm into all of the gaps. Exact position control without anchor under the water is not easy. Therefore, we designed the multi leg robot for the role of anchoring and positioning. Quadruped robot design of installing sole cameras was a new approach for the exact and stable position control on the IRWST strainer, unlike a traditional robot for underwater facility inspection. The developed robot will be practically used to enhance the efficiency and reliability of the inspection of nuclear power plant components.

The Obstacle Avoidance Algorithm of Mobile Robot using Line Histogram Intensity (Line Histogram Intensity를 이용한 이동로봇의 장애물 회피 알고리즘)

  • 류한성;최중경;구본민;박무열;방만식
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.8
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    • pp.1365-1373
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    • 2002
  • In this paper, we present two types of vision algorithm that mobile robot has CCD camera. for obstacle avoidance. This is simple algorithm that compare with grey level from input images. Also, The mobile robot depend on image processing and move command from PC host. we has been studied self controlled mobile robot system with CCD camera. This system consists of digital signal processor, step motor, RF module and CCD camera. we used wireless RF module for movable command transmitting between robot and host PC. This robot go straight until recognize obstacle from input image that preprocessed by edge detection, converting, thresholding. And it could avoid the obstacle when recognize obstacle by line histogram intensity. Host PC measurement wave from various line histogram each 20 pixel. This histogram is (x, y) value of pixel. For example, first line histogram intensity wave from (0, 0) to (0, 197) and last wave from (280, 0) to (2n, 197. So we find uniform wave region and nonuniform wave region. The period of uniform wave is obstacle region. we guess that algorithm is very useful about moving robot for obstacle avoidance.

Design and Implementation of Optimal Smart Home Control System (최적의 스마트 홈 제어 시스템 설계 및 구현)

  • Lee, Hyoung-Ro;Lin, Chi-Ho
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.18 no.1
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    • pp.135-141
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    • 2018
  • In this paper, we describe design and implementation of optimal smart home control system. Recent developments in technologies such as sensors and communication have enabled the Internet of Things to control a wide range of objects, such as light bulbs, socket-outlet, or clothing. Many businesses rely on the launch of collaborative services between them. However, traditional IoT systems often support a single protocol, although data is transmitted across multiple protocols for end-to-end devices. In addition, depending on the manufacturer of the Internet of things, there is a dedicated application and it has a high degree of complexity in registering and controlling different IoT devices for the internet of things. ARIoT system, special marking points and edge extraction techniques are used to detect objects, but there are relatively low deviations depending on the sampling data. The proposed system implements an IoT gateway of object based on OneM2M to compensate for existing problems. It supports diverse protocols of end to end devices and supported them with a single application. In addition, devices were learned by using deep learning in the artificial intelligence field and improved object recognition of existing systems by inference and detection, reducing the deviation of recognition rates.

Current Trends and Recent Advances in Diagnosis, Therapy, and Prevention of Hepatocellular Carcinoma

  • Wang, Chun-Hsiang;Wey, Keh-Cherng;Mo, Lein-Ray;Chang, Kuo-Kwan;Lin, Ruey-Chang;Kuo, Jen-Juan
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.9
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    • pp.3595-3604
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    • 2015
  • Hepatocellular carcinoma (HCC) has been one of the most fatal malignant tumors worldwide and its associated morbidity and mortality remain of significant concern. Based on in-depth reviews of serological diagnosis of HCC, in addition to AFP, there are other biomarkers: Lens culinaris agglutinin-reactive AFP (AFP-L3), descarboxyprothrombin (DCP), tyrosine kinase with Ig and eprdermal growth factor (EGF) homology domains 2 (TIE2)-espressing monocytes (TEMs), glypican-3 (GPC3), Golgi protein 73 (GP73), interleukin-6 (IL-6), and squamous cell carcinoma antigen (SCCA) have been proposed as biomarkers for the early detection of HCC. The diagnosis of HCC is primarily based on noninvasive standard imaging methods, such as ultrasound (US), dynamic multiphasic multidetector-row CT (MDCT) and magnetic resonance imaging (MRI). Some experts advocate gadolinium diethyl-enetriamine pentaacetic acid (Gd-EOB-DTPA) MRI and contrast-enhanced US as the promising imaging madalities of choice. With regard to recent advancements in tissue markers, many cuting-edge technologies using genome-wide DNA microarrays, qRT-PCR, and proteomic and inmunostaining studies have been implemented in an attempt to identify markers for early diagnosis of HCC. Only less than half of HCC patients at initial diagnosis are at an early stage treatable with curative options: local ablation, surgical resection, or liver transplant. Transarterial chemoembolization (TACE) is considered the standard of care with palliation for intermediate stage HCC. Recent innovative procedures using drug-eluting-beads and radioembolization using Yttrium-90 may exhibit beneficial effects in HCC treatment. During the past few years, several molecular targeted agents have been evaluated in clinical trials in advanced HCC. Sorafenib is currently the only approved systemic treatment for HCC. It has been approved for the therapy of asymptomatic HCC patients with well-preserved liver function who are not candidates for potentially curative treatments, such as surgical resection or liver transplantation. In the USA, Europe and particularly Japan, hepatitis C virus (HCV) related HCC accounts for most liver cancer, as compared with Asia-Pacific regions, where hepatitis B virus (HBV) may play a more important role in HCC development. HBV vaccination, while a vaccine is not yet available against HCV, has been recognized as a best primary prevention method for HBV-related HCC, although in patients already infected with HBV or HCV, secondary prevention with antiviral therapy is still a reasonable strategy. In addition to HBV and HCV, attention should be paid to other relevant HCC risk factors, including nonalcoholic fatty liver disease due to obesity and diabetes, heavy alcohol consumption, and prolonged aflatoxin exposure. Interestingly, coffee and vitamin K2 have been proven to provide protective effects against HCC. Regarding tertiary prevention of HCC recurrence after surgical resection, addition of antiviral treatment has proven to be a rational strategy.