• Title/Summary/Keyword: Image Feature

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Local Feature Detection on the Ocular Fundus Fluorescein angiogram Using Relaxation Process (이완법을 이용한 형광안저화상의 국소특징 검출)

  • 高昌林
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.24 no.5
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    • pp.856-862
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    • 1987
  • An local adaptive image segmentatin algorithm for local feature detection and effective clustering of unimodal histogram shape are proposed. Local adaptive difference image and its histogram are obtained from the input image. The parameters are derived from the histogram and used for the segmentation based on relaxatin process. The results showed effective region segmentation and good noise cleaning for the ocular fundus fluorescein angiogram which has low contrast and unimodal histogram.

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Feature Extraction and Statistical Pattern Recognition for Image Data using Wavelet Decomposition

  • Kim, Min-Soo;Baek, Jang-Sun
    • Communications for Statistical Applications and Methods
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    • v.6 no.3
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    • pp.831-842
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    • 1999
  • We propose a wavelet decomposition feature extraction method for the hand-written character recognition. Comparing the recognition rates of which methods with original image features and with selected features by the wavelet decomposition we study the characteristics of the proposed method. LDA(Linear Discriminant Analysis) QDA(Quadratic Discriminant Analysis) RDA(Regularized Discriminant Analysis) and NN(Neural network) are used for the calculation of recognition rates. 6000 hand-written numerals from CENPARMI at Concordia University are used for the experiment. We found that the set of significantly selected wavelet decomposed features generates higher recognition rate than the original image features.

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Panoramic Image Composition Algorithm through Scaling and Rotation Invariant Features (크기 및 회전 불변 특징점을 이용한 파노라마 영상 합성 알고리즘)

  • Kwon, Ki-Won;Lee, Hae-Yeoun;Oh, Duk-Hwan
    • The KIPS Transactions:PartB
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    • v.17B no.5
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    • pp.333-344
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    • 2010
  • This paper addresses the way to compose paronamic images from images taken the same objects. With the spread of digital camera, the panoramic image has been studied to generate with its interest. In this paper, we propose a panoramic image generation method using scaling and rotation invariant features. First, feature points are extracted from input images and matched with a RANSAC algorithm. Then, after the perspective model is estimated, the input image is registered with this model. Since the SURF feature extraction algorithm is adapted, the proposed method is robust against geometric distortions such as scaling and rotation. Also, the improvement of computational cost is achieved. In the experiment, the SURF feature in the proposed method is compared with features from Harris corner detector or the SIFT algorithm. The proposed method is tested by generating panoramic images using $640{\times}480$ images. Results show that it takes 0.4 second in average for computation and is more efficient than other schemes.

Fast Object Detection with DPM using Adaptive Bilinear Interpolated Image Pyramid (적응적 쌍선형 보간 이미지 피라미드를 이용한 DPM 기반 고속 객체 인식 기법)

  • Han, Gyu-Dong;Kim, Eung-Tae
    • Journal of Broadcast Engineering
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    • v.25 no.3
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    • pp.362-373
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    • 2020
  • Recently, as autonomous vehicles and intelligent CCTV are growing more interest, the efficient object detection is essential technique. The DPM(Deformable Part Models) which is basis of this paper have used a typical object system that represents highly variable objects using mixtures of deformable part for object. Although it shows high detection performance by capturing part shape and configuration of object model, but it is limited to use in real application due to the complicated algorithm. In this paper, instead of image feature pyramid that takes up a large amount of computation in one part of the detector, we propose a method to reduce the computation speed by reconstructing a new image feature pyramid that uses adaptive bilinear interpolation of feature maps obtained on a specific image scale. As a result, the detection performance for object was lowered a little by 2.82%, however, the proposed detection method improved the speed performance by 10% in comparison with original DPM.

Hyperspectral Image Fusion for Tumor Detection (초분광 영상 융합을 이용한 종양인식)

  • Xu Cheng-Zhe;Kim In-Taek
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.43 no.4 s.310
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    • pp.11-20
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    • 2006
  • This paper presents a method for detecting tumors on chicken carcasses by fusion of hyperspectral fluorescence and reflectance images. Classification of normal skin and tumor is performed by the image obtain 어 from optimal band ratio which minimizes the overlapping area of PDFs for normal skin and tumor. This method yields four feature images, each of them represents the ratio of two intensity values from a pixel. Classification is achieved by applying ISODATA to each pixel from the feature images. For the analysis of reflectance image, band selection method is proposed based on the information quantity, many effective features are acquired for the classification by defining the linear transformation selecting the projection axis, accordingly, accurate interpretation of images is possible in the reflectance image and automatic feature selection method is realized. Feature images from reflectance images are also classified by ISODATA and combined with the result from fluorescence images. Experimental result indicates that improved performance in term of reducing false detection rate is observed.

Gradual Block-based Efficient Lossy Location Coding for Image Retrieval (영상 검색을 위한 점진적 블록 크기 기반의 효율적인 손실 좌표 압축 기술)

  • Choi, Gyeongmin;Jung, Hyunil;Kim, Haekwang
    • Journal of Broadcast Engineering
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    • v.18 no.2
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    • pp.319-322
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    • 2013
  • Image retrieval research activity has moved its focus from global descriptors to local descriptors of feature point such as SIFT. MPEG is Currently working on standardization of effective coding of location and local descriptors of feature point in the context mobile based image search driven application in the name of MPEG-7 CDVS (Compact Descriptor for Visual Search). The extracted feature points consist of two parts, location information and Descriptor. For efficient image retrieval, we proposed a novel method that is gradual block-based efficient lossy location coding to compress location information according to distribution in images. From experimental result, the number of average bits per feature point reduce 5~6% and the accuracy rate keep compared to state of the art TM 3.0.

A Study on Implementation of the High Speed Feature Extraction System Based on Block Type Classification (블록 유형 분류 알고리즘 기반 고속 특징추출 시스템 구현에 관한 연구)

  • Lee, Juseong;An, Ho-Myoung
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.12 no.3
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    • pp.186-191
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    • 2019
  • In this paper, we propose a implementation approach of the high-speed feature extraction algorithm. The proposed method is based on the block type classification algorithm which reduces the computation time when target macro block is divided to smooth block type that has no image features. It is quantitatively identified that occurs at 29.5% of the total image using 200 standard test images with $64{\times}64$ macro block size. This means that within a standard test image containing various image information, 29.5% can reduce the complexity of the operation. When the proposed approach is applied to the Canny edge detection, the required latency of the edge detection can be completely eliminated, such as 2D derivative filter, gradient magnitude/direction computation, non-maximal suppression, adaptive threshold calculation, hysteresis thresholding. Also, it is expected that operation time of the feature detection can be reduced by applying block type classification algorithm to various feature extraction algorithms in this way.

Depth Map Estimation Model Using 3D Feature Volume (3차원 특징볼륨을 이용한 깊이영상 생성 모델)

  • Shin, Soo-Yeon;Kim, Dong-Myung;Suh, Jae-Won
    • The Journal of the Korea Contents Association
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    • v.18 no.11
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    • pp.447-454
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    • 2018
  • This paper proposes a depth image generation algorithm of stereo images using a deep learning model composed of a CNN (convolutional neural network). The proposed algorithm consists of a feature extraction unit which extracts the main features of each parallax image and a depth learning unit which learns the parallax information using extracted features. First, the feature extraction unit extracts a feature map for each parallax image through the Xception module and the ASPP(Atrous spatial pyramid pooling) module, which are composed of 2D CNN layers. Then, the feature map for each parallax is accumulated in 3D form according to the time difference and the depth image is estimated after passing through the depth learning unit for learning the depth estimation weight through 3D CNN. The proposed algorithm estimates the depth of object region more accurately than other algorithms.

Study on Co-Simulation Method of Dynamics and Guidance Algorithms for Strap-Down Image Tracker Using Unity3D (Unity3D를 이용한 스트랩 다운 영상 추적기의 동역학 및 유도 법칙 알고리즘의 상호-시뮬레이션 방법에 관한 연구)

  • Marin, Mikael;Kim, Taeho;Bang, Hyochoong;Cho, Hanjin;Cho, Youngki;Choi, Yonghoon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.11
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    • pp.911-920
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    • 2018
  • In this study, we performed a study to track the angle between the guided weapon and the target by using the strap-down image seeker, and constructed a test bed that can simulate it visually. This paper describes a method to maintain high-performance feature distribution in the implementation of sparse feature tracking algorithm such as Lucas Kanade's optical flow algorithm for target tracking using image information. We have extended the feature tracking problem to the concept of feature management. To realize this, we constructed visual environment using Unity3D engine and developed image processing simulation using OpenCV. For the co-simulation, dynamic system modeling was performed with Matlab Simulink, the visual environment using Unity3D was constructed, and computer vision work using OpenCV was performed.

Feature Extraction of Disease Region in Stomach Images Based on DCT (DCT기반 위장영상 질환부위의 특징추출)

  • Ahn, Byeoung-Ju;Lee, Sang-Bock
    • Journal of the Korean Society of Radiology
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    • v.6 no.3
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    • pp.167-171
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    • 2012
  • In this paper, we present an algorithm to extract features about disease region in digital stomach images. For feature extraction, DCT coefficients of gastrointestinal imaging matrix was obtained. DCT coefficent matrix is concentrated energy in low frequency region, we were extracted 128 feature parameters in low frequency region. Extracted feature parameters can using for differential compression of PACS and, can using for input parameter in CAD.