• 제목/요약/키워드: Image Normalization

검색결과 245건 처리시간 0.027초

뇌기능 양전자방출단층촬영영상 분석 기법의 방법론적 고찰 (Methodological Review on Functional Neuroimaging Using Positron Emission Tomography)

  • 박해정
    • Nuclear Medicine and Molecular Imaging
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    • 제41권2호
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    • pp.71-77
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    • 2007
  • Advance of neuroimaging technique has greatly influenced recent brain research field. Among various neuroimaging modalities, positron emission tomography has played a key role in molecular neuroimaging though functional MRI has taken over its role in the cognitive neuroscience. As the analysis technique for PET data is more sophisticated, the complexity of the method is more increasing. Despite the wide usage of the neuroimaging techniques, the assumption and limitation of procedures have not often been dealt with for the clinician and researchers, which might be critical for reliability and interpretation of the results. In the current paper, steps of voxel-based statistical analysis of PET including preprocessing, intensity normalization, spatial normalization, and partial volume correction will be revisited in terms of the principles and limitations. Additionally, new image analysis techniques such as surface-based PET analysis, correlational analysis and multimodal imaging by combining PET and DTI, PET and TMS or EEG will also be discussed.

A Correction Approach to Bidirectional Effects of EO-1 Hyperion Data for Forest Classification

  • Park, Seung-Hwan;Kim, Choen
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.1470-1472
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    • 2003
  • Hyperion, as hyperspectral data, is carried on NASA’s EO-1 satellite, can be used in more subtle discrimination on forest cover, with 224 band in 360 ?2580 nm (10nm interval). In this study, Hyperion image is used to investigate the effects of topography on the classification of forest cover, and to assess whether the topographic correction improves the discrimination of species units for practical forest mapping. A publicly available Digital Elevation Model (DEM), at a scale of 1:25,000, is used to model the radiance variation on forest, considering MSR(Mean Spectral Ratio) on antithesis aspects. Hyperion, as hyperspectral data, is corrected on a pixel-by-pixel basis to normalize the scene to a uniform solar illumination and viewing geometry. As a result, the approach on topographic effect normalization in hyperspectral data can effectively reduce the variation in detected radiance due to changes in forest illumination, progress the classification of forest cover.

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연결 성분 분석과 크기 정규화를 이용한 도로 노면 표시와 숫자 인식 (Recognition of Road Surface Marks and Numbers Using Connected Component Analysis and Size Normalization)

  • 정민철
    • 반도체디스플레이기술학회지
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    • 제21권1호
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    • pp.22-26
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    • 2022
  • This paper proposes a new method for the recognition of road surface marks and numbers. The proposed method designates a region of interest on the road surface without first detecting a lane. The road surface markings are extracted by location and size using a connection component analysis. Distortion due to the perspective effect is minimized by normalizing the size of the road markings. The road surface marking of the connected component is recognized by matching it with the stored road marking templates. The proposed method is implemented using C language in Raspberry Pi 4 system with a camera module for a real-time image processing. The system was fixedly installed in a moving vehicle, and it recorded a video like a vehicle black box. Each frame of the recorded video was extracted, and then the proposed method was tested. The results show that the proposed method is successful for the recognition of road surface marks and numbers.

표정 정규화를 통한 얼굴 인식율 개선 (Improvement of Face Recognition Rate by Normalization of Facial Expression)

  • 김진옥
    • 정보처리학회논문지B
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    • 제15B권5호
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    • pp.477-486
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    • 2008
  • 얼굴의 기하학적 특징이 변하여 생기는 표정은 얼굴 인식 시스템의 인식 결과에 다양한 영향을 끼친다. 얼굴 인식율을 개선하기 위해 본 연구에서는 인식 대상 얼굴과 참조 얼굴 사이의 표정 차이를 줄이는 방법으로 얼굴 표정 정규화를 제안한다. 본 연구에서는 대형의 이미지 데이터베이스를 구축하지 않고도 한 개의 정지 이미지에 일반적인 얼굴 근육 모델을 이용하는 접근 방식을 제시하여 얼굴 표정 모델링과 정규화를 처리한다. 첫 번째 방식은 본능적으로 변하는 얼굴 표정의 생물학적 모델을 구축하기 위해 선형 근육 모델의 기하학적 계수를 예측하는 것이다. 두 번째 방식은 RBF(Radial Basis Function)기반의 보간과 와핑을 통해 주어진 표정에 따라 얼굴 근육 모델을 무표정한 얼굴로 정규화한 것이다. 실험 결과, 기저얼굴 방식, 지역 이진 패턴 방식, 회색조 상관측정 방식과 같은 얼굴 인식 과정의 전처리 단계로 본 연구의 표정 정규화 과정을 적용하면 정규화를 거치지 않은 것보다 더 높은 인식율을 보인다.

측면 포즈정규화를 통한 부분 영역을 이용한 포즈 변화에 강인한 얼굴 인식 (Face Recognition under Varying Pose using Local Area obtained by Side-view Pose Normalization)

  • 안병두;고한석
    • 대한전자공학회논문지SP
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    • 제42권4호
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    • pp.59-68
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    • 2005
  • 본 논문에서는 측면 포즈 정규화를 통해 얻어진 부분영역을 이용해 대상의 포즈 변화에 강인한 얼굴인식 방법을 제안한다. 포즈변화에 강인한 얼굴인식을 위해 일반적으로 사용되는 방법인 포즈 정규화 방법은 포즈정규화과정 중에 가려져 보이지 않는 영역에 대한 정보를 가지고 있지 않기 때문에 문제가 발생하게 된다 일반적으로는 보상을 통해 문제를 해결 하고 있지만, 보상에 의해 영상이 왜곡이 되거나 특징정보를 잃는 경우가 많다. 이런 문제를 해결하기 위해 깊이찬가 큰 영역에서 주로 발생하는 왜곡을 줄이도록 정면이 아닌 측면으로의 정규화를 시도한다 또한 정규화후 왜곡이 발생한 영역은 제거하고 왜곡이 발생하지 않은 영역만을 이용해 인식과정을 수행한다 포즈가 좌우변화만 존재하는 경우와 상하변화도 존재하는 경우 두 가지 경우로 나누어 다루었으며 각각의 경우에 대해 실험을 통해 인식 성능의 향상을 확인하였다

Study on Image Processing Techniques Applying Artificial Intelligence-based Gray Scale and RGB scale

  • Lee, Sang-Hyun;Kim, Hyun-Tae
    • International Journal of Advanced Culture Technology
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    • 제10권2호
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    • pp.252-259
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    • 2022
  • Artificial intelligence is used in fusion with image processing techniques using cameras. Image processing technology is a technology that processes objects in an image received from a camera in real time, and is used in various fields such as security monitoring and medical image analysis. If such image processing reduces the accuracy of recognition, providing incorrect information to medical image analysis, security monitoring, etc. may cause serious problems. Therefore, this paper uses a mixture of YOLOv4-tiny model and image processing algorithm and uses the COCO dataset for learning. The image processing algorithm performs five image processing methods such as normalization, Gaussian distribution, Otsu algorithm, equalization, and gradient operation. For RGB images, three image processing methods are performed: equalization, Gaussian blur, and gamma correction proceed. Among the nine algorithms applied in this paper, the Equalization and Gaussian Blur model showed the highest object detection accuracy of 96%, and the gamma correction (RGB environment) model showed the highest object detection rate of 89% outdoors (daytime). The image binarization model showed the highest object detection rate at 89% outdoors (night).

허프변환을 이용한 운전면허시험 코스의 개선 (A Study on the Improvement of the Drive-License Test Course using the Hough Transform)

  • 이준택;정동근;정창화
    • 한국인터넷방송통신학회논문지
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    • 제10권6호
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    • pp.153-159
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    • 2010
  • 본 논문은 영상처리를 통해 운전면허시험 시스템의 코스 주행 시스템을 개선하는 방법을 제시한다. 주행차량에 장착된 이미지 캡처장비를 통해, 디지털 이미지를 취득하고, 이에 대한 그레이스케일, 표본화, 허프변환 등의 영상처리과정을 거쳐 결정사항이 중앙시스템에 기록되고, 주행자에게 합격여부를 알려주게 되며, 이러한 시스템을 통해, 경제적이고 효율적인 운영이 가능해진다.

A tracking of the moving objects using normalized hue distribution in HSI color model

  • Shin Chang Hoon;Lim Kang Mo;Lee Se Yeun;Kim Yoon Ho;Lee Joo shin
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2004년도 학술대회지
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    • pp.823-826
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    • 2004
  • In this paper, A tracking of the moving objects using normalized hue distribution in HSI color model was proposed. Moving objects are detected by using difference image method and integral projection method to background image and objects image only with hue area. Hue information of the detected moving area are normalized by 24 levels from $0^{\circ}$ to $3600^{\circ}A$ distance in between normalized levels with a hue distribution chart of the normalized moving objects is used for the identity distinction feature parameters of the moving objects. To examine proposed method in this paper, image of moving cars are obtained by setting up three cameras at different places every 1 km on outer motorway. The simulation results of identity distinction show that it is possible to distinct the identity a distance in between normalization levels of a hue distribution chart without background.

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Introduction to convolutional neural network using Keras; an understanding from a statistician

  • Lee, Hagyeong;Song, Jongwoo
    • Communications for Statistical Applications and Methods
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    • 제26권6호
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    • pp.591-610
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    • 2019
  • Deep Learning is one of the machine learning methods to find features from a huge data using non-linear transformation. It is now commonly used for supervised learning in many fields. In particular, Convolutional Neural Network (CNN) is the best technique for the image classification since 2012. For users who consider deep learning models for real-world applications, Keras is a popular API for neural networks written in Python and also can be used in R. We try examine the parameter estimation procedures of Deep Neural Network and structures of CNN models from basics to advanced techniques. We also try to figure out some crucial steps in CNN that can improve image classification performance in the CIFAR10 dataset using Keras. We found that several stacks of convolutional layers and batch normalization could improve prediction performance. We also compared image classification performances with other machine learning methods, including K-Nearest Neighbors (K-NN), Random Forest, and XGBoost, in both MNIST and CIFAR10 dataset.

비젼에 의한 감성인식 (Emotion Recognition by Vision System)

  • 이상윤;오재흥;주영훈;심귀보
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2001년도 추계학술대회 학술발표 논문집
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    • pp.203-207
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    • 2001
  • In this Paper, we propose the neural network based emotion recognition method for intelligently recognizing the human's emotion using CCD color image. To do this, we first acquire the color image from the CCD camera, and then propose the method for recognizing the expression to be represented the structural correlation of man's feature Points(eyebrows, eye, nose, mouse) It is central technology that the Process of extract, separate and recognize correct data in the image. for representation is expressed by structural corelation of human's feature Points In the Proposed method, human's emotion is divided into four emotion (surprise, anger, happiness, sadness). Had separated complexion area using color-difference of color space by method that have separated background and human's face toughly to change such as external illumination in this paper. For this, we propose an algorithm to extract four feature Points from the face image acquired by the color CCD camera and find normalization face picture and some feature vectors from those. And then we apply back-prapagation algorithm to the secondary feature vector. Finally, we show the Practical application possibility of the proposed method.

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