• Title/Summary/Keyword: Local image feature

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An Improved Texture Feature Extraction Method for Recognizing Emphysema in CT Images

  • Peng, Shao-Hu;Nam, Hyun-Do
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.11
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    • pp.30-41
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    • 2010
  • In this study we propose a new texture feature extraction method based on an estimation of the brightness and structural uniformity of CT images representing the important characteristics for emphysema recognition. The Center-Symmetric Local Binary Pattern (CS-LBP) is first used to combine gray level in order to describe the brightness uniformity characteristics of the CT image. Then the gradient orientation difference is proposed to generate another CS-LBP code combining with gray level to represent the structural uniformity characteristics of the CT image. The usage of the gray level, CS-LBP and gradient orientation differences enables the proposed method to extract rich and distinctive information from the CT images in multiple directions. Experimental results showed that the performance of the proposed method is more stable with respect to sensitivity and specificity when compared with the SGLDM, GLRLM and GLDM. The proposed method outperformed these three conventional methods (SGLDM, GLRLM, and GLDM) 7.85[%], 22.87[%], and 16.67[%] respectively, according to the diagnosis of average accuracy, demonstrated by the Receiver Operating Characteristic (ROC) curves.

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.

Extraction and Shape Description of Feature Region on Ocular Fundus Fluorescein Angiogram (형광 안저화상에 관한 특수 영역의 유출 및 모양)

  • Go, Chang-Rim;Ha, Yeong-Ho;Kim, Su-Jung
    • Journal of Biomedical Engineering Research
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    • v.8 no.1
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    • pp.81-86
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    • 1987
  • An image feature extraction method for the low contrast fluoresceln angiogram in dlabetes was studied. To obtain effective image segmentation, an adaptive local difference image is generated and relaxation process are applied to this difference Image. By the use of distance transformed data with segmented image, shape and location of feature regions were obtained. It was shown that the location and shape descriptions of Impaired blood vessel networks and retinal regions are can he utilized for the diagnosis of diabetes and other disease.

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A Grouping Method of Photographic Advertisement Information Based on the Efficient Combination of Features (특징의 효과적 병합에 의한 광고영상정보의 분류 기법)

  • Jeong, Jae-Kyong;Jeon, Byeung-Woo
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.48 no.2
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    • pp.66-77
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    • 2011
  • We propose a framework for grouping photographic advertising images that employs a hierarchical indexing scheme based on efficient feature combinations. The study provides one specific application of effective tools for monitoring photographic advertising information through online and offline channels. Specifically, it develops a preprocessor for advertising image information tracking. We consider both global features that contain general information on the overall image and local features that are based on local image characteristics. The developed local features are invariant under image rotation and scale, the addition of noise, and change in illumination. Thus, they successfully achieve reliable matching between different views of a scene across affine transformations and exhibit high accuracy in the search for matched pairs of identical images. The method works with global features in advance to organize coarse clusters that consist of several image groups among the image data and then executes fine matching with local features within each cluster to construct elaborate clusters that are separated by identical image groups. In order to decrease the computational time, we apply a conventional clustering method to group images together that are similar in their global characteristics in order to overcome the drawback of excessive time for fine matching time by using local features between identical images.

Feature Voting for Object Localization via Density Ratio Estimation

  • Wang, Liantao;Deng, Dong;Chen, Chunlei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.12
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    • pp.6009-6027
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    • 2019
  • Support vector machine (SVM) classifiers have been widely used for object detection. These methods usually locate the object by finding the region with maximal score in an image. With bag-of-features representation, the SVM score of an image region can be written as the sum of its inside feature-weights. As a result, the searching process can be executed efficiently by using strategies such as branch-and-bound. However, the feature-weight derived by optimizing region classification cannot really reveal the category knowledge of a feature-point, which could cause bad localization. In this paper, we represent a region in an image by a collection of local feature-points and determine the object by the region with the maximum posterior probability of belonging to the object class. Based on the Bayes' theorem and Naive-Bayes assumptions, the posterior probability is reformulated as the sum of feature-scores. The feature-score is manifested in the form of the logarithm of a probability ratio. Instead of estimating the numerator and denominator probabilities separately, we readily employ the density ratio estimation techniques directly, and overcome the above limitation. Experiments on a car dataset and PASCAL VOC 2007 dataset validated the effectiveness of our method compared to the baselines. In addition, the performance can be further improved by taking advantage of the recently developed deep convolutional neural network features.

Feature-based Image Analysis for Object Recognition on Satellite Photograph (인공위성 영상의 객체인식을 위한 영상 특징 분석)

  • Lee, Seok-Jun;Jung, Soon-Ki
    • Journal of the HCI Society of Korea
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    • v.2 no.2
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    • pp.35-43
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    • 2007
  • This paper presents a system for image matching and recognition based on image feature detection and description techniques from artificial satellite photographs. We propose some kind of parameters from the varied environmental elements happen by image handling process. The essential point of this experiment is analyzes that affects match rate and recognition accuracy when to change of state of each parameter. The proposed system is basically inspired by Lowe's SIFT(Scale-Invariant Transform Feature) algorithm. The descriptors extracted from local affine invariant regions are saved into database, which are defined by k-means performed on the 128-dimensional descriptor vectors on an artificial satellite photographs from Google earth. And then, a label is attached to each cluster of the feature database and acts as guidance for an appeared building's information in the scene from camera. This experiment shows the various parameters and compares the affected results by changing parameters for the process of image matching and recognition. Finally, the implementation and the experimental results for several requests are shown.

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Quality measures of Fingerprint images using the orientation (방향 정보를 이용한 지문 영상의 품질 측정)

  • 이상훈;임덕선;김재희
    • Proceedings of the IEEK Conference
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    • 2003.07e
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    • pp.1867-1870
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    • 2003
  • Since degraded region of input image can cause false minutiae which lead to decrease identification performance, use minutiae belong to only good quality to ensure true minutiae. This paper suggests image quality measuring method with respect to local and global orientation of ridges. In order to verify a suggested method, PDFs of quality indices derived by local and global feature are computed and then, classifying each image block using Bayesian decision theory.

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A New Shape Adaptation Scheme to Affine Invariant Detector

  • Liu, Congxin;Yang, Jie;Zhou, Yue;Feng, Deying
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.4 no.6
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    • pp.1253-1272
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    • 2010
  • In this paper, we propose a new affine shape adaptation scheme for the affine invariant feature detector, in which the convergence stability is still an opening problem. This paper examines the relation between the integration scale matrix of next iteration and the current second moment matrix and finds that the convergence stability of the method can be improved by adjusting the relation between the two matrices instead of keeping them always proportional as proposed by previous methods. By estimating and updating the shape of the integration kernel and differentiation kernel in each iteration based on the anisotropy of the current second moment matrix, we propose a coarse-to-fine affine shape adaptation scheme which is able to adjust the pace of convergence and enable the process to converge smoothly. The feature matching experiments demonstrate that the proposed approach obtains an improvement in convergence ratio and repeatability compared with the current schemes with relatively fixed integration kernel.

Framework for Content-Based Image Identification with Standardized Multiview Features

  • Das, Rik;Thepade, Sudeep;Ghosh, Saurav
    • ETRI Journal
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    • v.38 no.1
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    • pp.174-184
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    • 2016
  • Information identification with image data by means of low-level visual features has evolved as a challenging research domain. Conventional text-based mapping of image data has been gradually replaced by content-based techniques of image identification. Feature extraction from image content plays a crucial role in facilitating content-based detection processes. In this paper, the authors have proposed four different techniques for multiview feature extraction from images. The efficiency of extracted feature vectors for content-based image classification and retrieval is evaluated by means of fusion-based and data standardization-based techniques. It is observed that the latter surpasses the former. The proposed methods outclass state-of-the-art techniques for content-based image identification and show an average increase in precision of 17.71% and 22.78% for classification and retrieval, respectively. Three public datasets - Wang; Oliva and Torralba (OT-Scene); and Corel - are used for verification purposes. The research findings are statistically validated by conducting a paired t-test.

3D Face Recognition using Local Depth Information

  • 이영학;심재창;이태홍
    • Journal of KIISE:Software and Applications
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    • v.29 no.11
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    • pp.818-825
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    • 2002
  • Depth information is one of the most important factor for the recognition of a digital face image. Range images are very useful, when comparing one face with other faces, because of implicating depth information. As the processing for the whole fare produces a lot of calculations and data, face images ran be represented in terms of a vector of feature descriptors for a local area. In this paper, depth areas of a 3 dimensional(3D) face image were extracted by the contour line from some depth value. These were resampled and stored in consecutive location in feature vector using multiple feature method. A comparison between two faces was made based on their distance in the feature space, using Euclidian distance. This paper reduced the number of index data in the database and used fewer feature vectors than other methods. Proposed algorithm can be highly recognized for using local depth information and less feature vectors or the face.