• Title/Summary/Keyword: Histograms

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Image Retrieval Using Entropy-Based Image Segmentation (엔트로피에 기반한 영상분할을 이용한 영상검색)

  • Jang, Dong-Sik;Yoo, Hun-Woo;Kang, Ho-Jueng
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.4
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    • pp.333-337
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    • 2002
  • A content-based image retrieval method using color, texture, and shape features is proposed in this paper. A region segmentation technique using PIM(Picture Information Measure) entropy is used for similarity indexing. For segmentation, a color image is first transformed to a gray image and it is divided into n$\times$n non-overlapping blocks. Entropy using PIM is obtained from each block. Adequate variance to perform good segmentation of images in the database is obtained heuristically. As variance increases up to some bound, objects within the image can be easily segmented from the background. Therefore, variance is a good indication for adequate image segmentation. For high variance image, the image is segmented into two regions-high and low entropy regions. In high entropy region, hue-saturation-intensity and canny edge histograms are used for image similarity calculation. For image having lower variance is well represented by global texture information. Experiments show that the proposed method displayed similar images at the average of 4th rank for top-10 retrieval case.

A Content-Based Image Retrieval Technique Using the Shape and Color Features of Objects (객체의 모양과 색상특징을 이용한 내용기반 영상검색 기법)

  • 박종현;박순영;오일환
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.10B
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    • pp.1902-1911
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    • 1999
  • In this paper we present a content-based image retrieval algorithm using the visual feature vectors which describe the spatial characteristics of objects. The proposed technique uses the Gaussian mixture model(GMM) to represent multi-colored objects and the expectation maximization(EM) algorithm is employed to estimate the maximum likelihood(ML) parameters of the model. After image segmentation is performed based on GMM, the shape and color features are extracted from each object using Fourier descriptors and color histograms, respectively. Image retrieval consists of two steps: first, the shape-based query is carried out to find the candidate images whose objects have the similar shapes with the query image and second, the color-based query is followed. The experimental results show that the proposed algorithm is effective in image retrieving by using the spatial and visual features of segmented objects.

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Region-Based Facial Expression Recognition in Still Images

  • Nagi, Gawed M.;Rahmat, Rahmita O.K.;Khalid, Fatimah;Taufik, Muhamad
    • Journal of Information Processing Systems
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    • v.9 no.1
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    • pp.173-188
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    • 2013
  • In Facial Expression Recognition Systems (FERS), only particular regions of the face are utilized for discrimination. The areas of the eyes, eyebrows, nose, and mouth are the most important features in any FERS. Applying facial features descriptors such as the local binary pattern (LBP) on such areas results in an effective and efficient FERS. In this paper, we propose an automatic facial expression recognition system. Unlike other systems, it detects and extracts the informative and discriminant regions of the face (i.e., eyes, nose, and mouth areas) using Haar-feature based cascade classifiers and these region-based features are stored into separate image files as a preprocessing step. Then, LBP is applied to these image files for facial texture representation and a feature-vector per subject is obtained by concatenating the resulting LBP histograms of the decomposed region-based features. The one-vs.-rest SVM, which is a popular multi-classification method, is employed with the Radial Basis Function (RBF) for facial expression classification. Experimental results show that this approach yields good performance for both frontal and near-frontal facial images in terms of accuracy and time complexity. Cohn-Kanade and JAFFE, which are benchmark facial expression datasets, are used to evaluate this approach.

Moving Picture Compression using Frame Classification by Luminance Characteristics (명암특성에 따른 프레임 분류를 이용한 동영상 압축기법)

  • Kim, Sang-Hyun
    • The Journal of the Korea Contents Association
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    • v.11 no.4
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    • pp.51-56
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    • 2011
  • This paper proposes an efficient moving picture compression for video sequences with luminance variations. In the proposed algorithm, the luminance variation parameters are estimated and local motions are compensated. To detect the frame required luminance compensation, we employ the frame classification based on the cross entropy between histograms of two successive frames, which can reduce the computational redundancy. Simulation results show that the proposed method yields a higher peak signal to noise ratio (PSNR) than that of the conventional methods, with a low computational load, when the video scene contains large luminance variations.

A Divisive Clustering for Mixed Feature-Type Symbolic Data (혼합형태 심볼릭 데이터의 군집분석방법)

  • Kim, Jaejik
    • The Korean Journal of Applied Statistics
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    • v.28 no.6
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    • pp.1147-1161
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    • 2015
  • Nowadays we are considering and analyzing not only classical data expressed by points in the p-dimensional Euclidean space but also new types of data such as signals, functions, images, and shapes, etc. Symbolic data also can be considered as one of those new types of data. Symbolic data can have various formats such as intervals, histograms, lists, tables, distributions, models, and the like. Up to date, symbolic data studies have mainly focused on individual formats of symbolic data. In this study, it is extended into datasets with both histogram and multimodal-valued data and a divisive clustering method for the mixed feature-type symbolic data is introduced and it is applied to the analysis of industrial accident data.

Retrieval of Identical Clothing Images Based on Non-Static Color Histogram Analysis

  • Choi, Yoo-Joo;Moon, Nam-Mee;Kim, Ku-Jin
    • Journal of Broadcast Engineering
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    • v.14 no.4
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    • pp.397-408
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    • 2009
  • In this paper, we present a non-static color histogram method to retrieve clothing images that are similar to a query clothing. Given clothing area, our method automatically extracts major colors by using the octree-based quantization approach[16]. Then, a color palette that is composed of the major colors is generated. The feature of each clothing, which can be either a query or a database clothing image, is represented as a color histogram based on its color palette. We define the match color bins between two possibly different color palettes, and unify the color palettes by merging or deleting some color bins if necessary. The similarity between two histograms is measured by using the weighted Euclidean distance between the match color bins, where the weight is derived from the frequency of each bin. We compare our method with previous histogram matching methods through experiments. Compared to HSV cumulative histogram-based approach, our method improves the retrieval precision by 13.7 % with less number of color bins.

DWTHE: Decomposable Weighted and Thresholded Histogram Equalization (DWTHE: 분할 기반의 히스토그램 평활화)

  • Kim, Mary;Chung, Min-Gyo
    • Journal of KIISE:Computing Practices and Letters
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    • v.15 no.11
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    • pp.856-860
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    • 2009
  • Wang and Ward developed an image contrast enhancement method called WTHE (Weighted and Thresholded Histogram Equalization). In this paper, we propose an improved variant of WTHE called DWTHE(Decomposable WTHE) that enhances WTHE through the use of histogram decomposition. Specifically, DWTHE divides an input histogram by using image's mean brightness or equally-spaced brightness points, computes a probability value for each sub-histogram, modifies the sub-histograms by using those probability values as weights, and then performs histogram equalization on the modified input histogram. As opposed to WTHE that uses a single weight, DWTHE uses multiple weights derived from histogram decomposition. Experimental results show that the proposed method outperforms the previous histogram equalization based methods.

EVALUATION OF MARINE SURFACE WINDS OBSERVED BY ACTIVE AND PASSIVE MICROWAVE SENSORS ON ADEOS-II

  • Ebuchi, Naoto
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.146-149
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    • 2006
  • Marine surface winds observed by two microwave sensors, SeaWinds and Advanced Microwave Scanning Radiometer (AMSR), on the Advanced Earth Observing Satellite-II (ADEOS-II) are evaluated by comparison with off-shore moored buoy observations. The wind speed and direction observed by SeaWinds are in good agreement with buoy data with root-mean-squared (rms) differences of approximately 1 m $s^{-1}$ and $20^{\circ}$, respectively. No systematic biases depending on wind speed or cross-track wind vector cell location are discernible. The effects of oceanographic and atmospheric environments on the scatterometry are negligible. The wind speed observed by AMSR also exhibited reasonable agreement with the buoy data in general with rms difference of 1.2 m $s^{-1}$. Systematic bias which was observed in earlier versions of the AMSR winds has been removed by algorithm refinements. Intercomparison of wind speeds globally observed by SeaWinds and AMSR on the same orbits also shows good agreements. Global wind speed histograms of the SeaWinds data and European Centre for Medium-range Weather Forecasts (ECMWF) analyses agree precisely with each other, while that of the AMSR wind shows slight deviation from them.

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In-Vehicle AR-HUD System to Provide Driving-Safety Information

  • Park, Hye Sun;Park, Min Woo;Won, Kwang Hee;Kim, Kyong-Ho;Jung, Soon Ki
    • ETRI Journal
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    • v.35 no.6
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    • pp.1038-1047
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    • 2013
  • Augmented reality (AR) is currently being applied actively to commercial products, and various types of intelligent AR systems combining both the Global Positioning System and computer-vision technologies are being developed and commercialized. This paper suggests an in-vehicle head-up display (HUD) system that is combined with AR technology. The proposed system recognizes driving-safety information and offers it to the driver. Unlike existing HUD systems, the system displays information registered to the driver's view and is developed for the robust recognition of obstacles under bad weather conditions. The system is composed of four modules: a ground obstacle detection module, an object decision module, an object recognition module, and a display module. The recognition ratio of the driving-safety information obtained by the proposed AR-HUD system is about 73%, and the system has a recognition speed of about 15 fps for both vehicles and pedestrians.

A Speed-up Method of HOG Pedestrian Detector in Advanced SIMD Architecture (Advanced SIMD 아키텍처에서의 HOG 보행자 검출기 고속화 방법)

  • Kwon, Ki-Pyo;Lee, Jae-Heung
    • Journal of IKEEE
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    • v.18 no.1
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    • pp.106-113
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    • 2014
  • A pedestrian detector can be applied for various purposes such as monitoring or counting the number of people in some place, or detecting the people plunging in the driveway. There was a lot of related research. But, the detection speed is slow in embedded system because of the limited computing power. An algorithm for fast pedestrian detector using HOG in ARM SIMD architecture is presented in this paper. There is a way to quickly remove the background of image and to improve the detection speed using NEON parallel technique. When we tested with INRIA Person Dataset, the proposed pedestrian detector improves the speed by 3.01 times than previous one.