• Title/Summary/Keyword: Feature-based image matching

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Improved Vapor Recognition in Electronic Nose (E-Nose) System by Using the Time-Profile of Sensor Array Response (센서 응답의 Time-Profile 을 이용한 전자 후각 (E-Nose) 시스템의 Vapor 인식 성능 향상)

  • Yoon Seok, Yang
    • Journal of Biomedical Engineering Research
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    • v.25 no.5
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    • pp.329-334
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    • 2004
  • The electronic nose (E-nose) recently finds its applications in medical diagnosis, specifically on detection of diabetes, pulmonary or gastrointestinal problem, or infections by examining odors in the breath or tissues with its odor characterizing ability. The odor recognition performance of E-nose can be improved by manipulating the sensor array responses of vapors in time-profile forms. The different chemical interactions between the sensor materials and the volatile organic compounds (VOC's) leave unique marks in the signal profiles giving more information than collection of the conventional piecemal features, i.e., maximum sensitivity, signal slopes, rising time. In this study, to use them in vapor recognition task conveniently, a novel time-profile method was proposed, which is adopted from digital image pattern matching. The degrees of matching between 8 different vapors were evaluated by using the proposed method. The test vapors are measured by the silicon-based gas sensor array with 16 CB-polymer composites installed in membrane structure. The results by the proposed method showed clear discrimination of vapor species than by the conventional method.

Efficient Representation and Matching of Object Movement using Shape Sequence Descriptor (모양 시퀀스 기술자를 이용한 효과적인 동작 표현 및 검색 방법)

  • Choi, Min-Seok
    • The KIPS Transactions:PartB
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    • v.15B no.5
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    • pp.391-396
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    • 2008
  • Motion of object in a video clip often plays an important role in characterizing the content of the clip. A number of methods have been developed to analyze and retrieve video contents using motion information. However, most of these methods focused more on the analysis of direction or trajectory of motion but less on the analysis of the movement of an object itself. In this paper, we propose the shape sequence descriptor to describe and compare the movement based on the shape deformation caused by object motion along the time. A movement information is first represented a sequence of 2D shape of object extracted from input image sequence, and then 2D shape information is converted 1D shape feature using the shape descriptor. The shape sequence descriptor is obtained from the shape descriptor sequence by frequency transform along the time. Our experiment results show that the proposed method can be very simple and effective to describe the object movement and can be applicable to semantic applications such as content-based video retrieval and human movement recognition.

Geometrical Feature-Based Detection of Pure Facial Regions (기하학적 특징에 기반한 순수 얼굴영역 검출기법)

  • 이대호;박영태
    • Journal of KIISE:Software and Applications
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    • v.30 no.7_8
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    • pp.773-779
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    • 2003
  • Locating exact position of facial components is a key preprocessing for realizing highly accurate and reliable face recognition schemes. In this paper, we propose a simple but powerful method for detecting isolated facial components such as eyebrows, eyes, and a mouth, which are horizontally oriented and have relatively dark gray levels. The method is based on the shape-resolving locally optimum thresholding that may guarantee isolated detection of each component. We show that pure facial regions can be determined by grouping facial features satisfying simple geometric constraints on unique facial structure. In the test for over 1000 images in the AR -face database, pure facial regions were detected correctly for each face image without wearing glasses. Very few errors occurred in the face images wearing glasses with a thick frame because of the occluded eyebrow -pairs. The proposed scheme may be best suited for the later stage of classification using either the mappings or a template matching, because of its capability of handling rotational and translational variations.

Fixed-Point Modeling and Performance Analysis of a SIFT Keypoints Localization Algorithm for SoC Hardware Design (SoC 하드웨어 설계를 위한 SIFT 특징점 위치 결정 알고리즘의 고정 소수점 모델링 및 성능 분석)

  • Park, Chan-Ill;Lee, Su-Hyun;Jeong, Yong-Jin
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.6
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    • pp.49-59
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    • 2008
  • SIFT(Scale Invariant Feature Transform) is an algorithm to extract vectors at pixels around keypoints, in which the pixel colors are very different from neighbors, such as vortices and edges of an object. The SIFT algorithm is being actively researched for various image processing applications including 3-D image constructions, and its most computation-intensive stage is a keypoint localization. In this paper, we develope a fixed-point model of the keypoint localization and propose its efficient hardware architecture for embedded applications. The bit-length of key variables are determined based on two performance measures: localization accuracy and error rate. Comparing with the original algorithm (implemented in Matlab), the accuracy and error rate of the proposed fixed point model are 93.57% and 2.72% respectively. In addition, we found that most of missing keypoints appeared at the edges of an object which are not very important in the case of keypoints matching. We estimate that the hardware implementation will give processing speed of $10{\sim}15\;frame/sec$, while its fixed point implementation on Pentium Core2Duo (2.13 GHz) and ARM9 (400 MHz) takes 10 seconds and one hour each to process a frame.

Measurement Technique of Indoor location Based on Markerless applicable to AR (AR에 적용 가능한 마커리스 기반의 실내 위치 측정 기법)

  • Kim, Jae-Hyeong;Lee, Seung-Ho
    • Journal of IKEEE
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    • v.25 no.2
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    • pp.243-251
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    • 2021
  • In this paper, we propose a measurement technique of indoor location based on markerless applicable to AR. The proposed technique has the following originality. The first is to extract feature points and use them to generate local patches to enable faster computation by learning and using only local patches that are more useful than the surroundings without learning the entire image. Second, learning is performed through deep learning using the convolution neural network structure to improve accuracy by reducing the error rate. Third, unlike the existing feature point matching technique, it enables indoor location measurement including left and right movement. Fourth, since the indoor location is newly measured every frame, errors occurring in the front side during movement are prevented from accumulating. Therefore, it has the advantage that the error between the final arrival point and the predicted indoor location does not increase even if the moving distance increases. As a result of the experiment conducted to evaluate the time required and accuracy of the measurement technique of indoor location based on markerless applicable to AR proposed in this paper, the difference between the actual indoor location and the measured indoor location is an average of 12.8cm and a maximum of 21.2cm. As measured, the indoor location measurement accuracy was better than that of the existing IEEE paper. In addition, it was determined that it was possible to measure the user's indoor location in real time by displaying the measured result at 20 frames per second.

Lane Detection in Complex Environment Using Grid-Based Morphology and Directional Edge-link Pairs (복잡한 환경에서 Grid기반 모폴리지와 방향성 에지 연결을 이용한 차선 검출 기법)

  • Lin, Qing;Han, Young-Joon;Hahn, Hern-Soo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.20 no.6
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    • pp.786-792
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    • 2010
  • This paper presents a real-time lane detection method which can accurately find the lane-mark boundaries in complex road environment. Unlike many existing methods that pay much attention on the post-processing stage to fit lane-mark position among a great deal of outliers, the proposed method aims at removing those outliers as much as possible at feature extraction stage, so that the searching space at post-processing stage can be greatly reduced. To achieve this goal, a grid-based morphology operation is firstly used to generate the regions of interest (ROI) dynamically, in which a directional edge-linking algorithm with directional edge-gap closing is proposed to link edge-pixels into edge-links which lie in the valid directions, these directional edge-links are then grouped into pairs by checking the valid lane-mark width at certain height of the image. Finally, lane-mark colors are checked inside edge-link pairs in the YUV color space, and lane-mark types are estimated employing a Bayesian probability model. Experimental results show that the proposed method is effective in identifying lane-mark edges among heavy clutter edges in complex road environment, and the whole algorithm can achieve an accuracy rate around 92% at an average speed of 10ms/frame at the image size of $320{\times}240$.

Descent Dataset Generation and Landmark Extraction for Terrain Relative Navigation on Mars (화성 지형상대항법을 위한 하강 데이터셋 생성과 랜드마크 추출 방법)

  • Kim, Jae-In
    • Korean Journal of Remote Sensing
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    • v.38 no.6_1
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    • pp.1015-1023
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    • 2022
  • The Entry-Descent-Landing process of a lander involves many environmental and technical challenges. To solve these problems, recently, terrestrial relative navigation (TRN) technology has been essential for landers. TRN is a technology for estimating the position and attitude of a lander by comparing Inertial Measurement Unit (IMU) data and image data collected from a descending lander with pre-built reference data. In this paper, we present a method for generating descent dataset and extracting landmarks, which are key elements for developing TRN technologies to be used on Mars. The proposed method generates IMU data of a descending lander using a simulated Mars landing trajectory and generates descent images from high-resolution ortho-map and digital elevation map through a ray tracing technique. Landmark extraction is performed by an area-based extraction method due to the low-textured surfaces on Mars. In addition, search area reduction is carried out to improve matching accuracy and speed. The performance evaluation result for the descent dataset generation method showed that the proposed method can generate images that satisfy the imaging geometry. The performance evaluation result for the landmark extraction method showed that the proposed method ensures several meters of positioning accuracy while ensuring processing speed as fast as the feature-based methods.

Virtual core point detection and ROI extraction for finger vein recognition (지정맥 인식을 위한 가상 코어점 검출 및 ROI 추출)

  • Lee, Ju-Won;Lee, Byeong-Ro
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.10 no.3
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    • pp.249-255
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    • 2017
  • The finger vein recognition technology is a method to acquire a finger vein image by illuminating infrared light to the finger and to authenticate a person through processes such as feature extraction and matching. In order to recognize a finger vein, a 2D mask-based two-dimensional convolution method can be used to detect a finger edge but it takes too much computation time when it is applied to a low cost micro-processor or micro-controller. To solve this problem and improve the recognition rate, this study proposed an extraction method for the region of interest based on virtual core points and moving average filtering based on the threshold and absolute value of difference between pixels without using 2D convolution and 2D masks. To evaluate the performance of the proposed method, 600 finger vein images were used to compare the edge extraction speed and accuracy of ROI extraction between the proposed method and existing methods. The comparison result showed that a processing speed of the proposed method was at least twice faster than those of the existing methods and the accuracy of ROI extraction was 6% higher than those of the existing methods. From the results, the proposed method is expected to have high processing speed and high recognition rate when it is applied to inexpensive microprocessors.

Study for making movie poster applied Augmented Reality (증강현실 영화포스터 제작연구)

  • Lee, Ki Ho
    • Cartoon and Animation Studies
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    • s.48
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    • pp.359-383
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    • 2017
  • 3,000 years ago, since the first poster of humanity appeared in Egypt, the invention of printing technique and the development of civilization have accelerated the poster production technology. In keeping with this, the expression of poster has also been developed as an attempt to express artistic sensibility in a simple arrangement of characters, and now it has become an art form that has become a domain of professional designers. However, the technological development in the expression of poster is keep staying in two-dimensional, and is dependent on printing only that it is irrelevant to the change of ICT environment based on modern multimedia. Especially, among the many kinds of posters, the style of movie posters, which are the only objects for video, are still printed on paper, and many attempts have been made so far, but the movie industry still does not consider ICT integration at all. This study started with the feature that the object of the movie poster dealt with the video and attempted to introduce the augmented reality to apply the dynamic image of the movie to the static poster. In the graduation work of the media design major of a university in Korea, the poster of each works for promoting the visual work of the students was designed and printed in the form of a commercial film poster. Among them, 6 artworks that are considered to be suitable for augmented reality were selected and augmented reality was introduced and exhibited. Content that appears matched to the poster through the mobile device is reproduced on a poster of a scene of the video, but the text informations of the original poster are kept as they are, so that is able to build a moving poster looked like a wanted from the movie "Harry Potter". In order to produce this augmented reality poster, we applied augmented reality to posters of existing commercial films produced in two different formats, and found a way to increase the characteristics of AR contents. Through this, we were able to understand poster design suitable for AR representation, and technical expression for stable operation of augmented reality can be summarized in the matching process of augmented reality contents production.