• Title/Summary/Keyword: image feature point search

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A Robust Algorithm for Tracking Feature Points with Incomplete Trajectories (불완전한 궤적을 고려한 강건한 특징점 추적 알고리즘)

  • Jeong, Jong-Myeon;Moon, Young-Shik
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.37 no.6
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    • pp.25-37
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    • 2000
  • The trajectories of feature points can be defined by the correspondences between points in consecutive frames. The correspondence problem is known to be difficult to solve because false positives and false negatives almost always exist in real image sequences. In this paper, we propose a robust feature tracking algorithm considering incomplete trajectories such as entering and/or vanishing trajectories. The trajectories of feature points are determined by calculating the matching measure, which is defined as the minimum weighted Euclidean distance between two feature points. The weights are automatically updated in order to properly reflect the motion characteristics. We solve the correspondence problem as an optimal graph search problem, considering that the existence of false feature points may have serious effect on the correspondence search. The proposed algorithm finds a local optimal correspondence so that the effect of false feature point can be minimized in the decision process. The time complexity of the proposed graph search algorithm is given by O(mn) in the best case and O($m^2n$) in the worst case, where m and n arc the number of feature points in two consecutive frames. By considering false feature points and by properly reflecting motion characteristics, the proposed algorithm can find trajectories correctly and robustly, which has been shown by experimental results.

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Local Context based Feature Extraction for Efficient Face Detection (효율적인 얼굴 검출을 위한 지역적 켄텍스트 기반의 특징 추출)

  • Rhee, Phill-Kyu;Xu, Yong Zhe;Shin, Hak-Chul;Shen, Yan
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.11 no.1
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    • pp.185-191
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    • 2011
  • Recently, the surveillance system is highly being attention. Various Technologies as detecting object from image than determining and recognizing if the object are person are universally being used. Therefore, In this paper shows detecting on this kind of object and local context based facial feather detection algorithm is being advocated. Detect using Gabor Bunch in the same time Bayesian detection method for revision to find feather point is being described. The entire system to search for object area from image, context-based face detection, feature extraction methods applied to improve the performance of the system.

Enhancement on 3 DoF Image Stitching Using Inertia Sensor Data (관성 센서 데이터를 활용한 3 DoF 이미지 스티칭 향상)

  • Kim, Minwoo;Kim, Sang-Kyun
    • Journal of Broadcast Engineering
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    • v.22 no.1
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    • pp.51-61
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    • 2017
  • This paper proposes a method to generate panoramic images by combining conventional feature extraction algorithms (e.g., SIFT, SURF, MPEG-7 CDVS) with sensed data from an inertia sensor to enhance the stitching results. The challenge of image stitching increases when the images are taken from two different mobile phones with no posture calibration. Using inertia sensor data obtained by the mobile phone, images with different yaw angles, pitch angles, roll angles are preprocessed and adjusted before performing stitching process. Performance of stitching (e.g., feature extraction time, inlier point numbers, stitching accuracy) between conventional feature extraction algorithms is reported along with the stitching performance with/without using the inertia sensor data.

Image-based Image Retrieval System Using Duplicated Point of PCA-SIFT (PCA-SIFT의 차원 중복점을 이용한 이미지 기반 이미지 검색 시스템)

  • Choi, GiRyong;Jung, Hye-Wuk;Lee, Jee-Hyoung
    • Journal of the Korean Institute of Intelligent Systems
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    • v.23 no.3
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    • pp.275-279
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    • 2013
  • Recently, as multimedia information becomes popular, there are many studies to retrieve images based on images in the web. However, it is hard to find the matching images which users want to find because of various patterns in images. In this paper, we suggest an efficient images retrieval system based on images for finding products in internet shopping malls. We extract features for image retrieval by using SIFT (Scale Invariant Feature Transform) algorithm, repeat keypoint matching in various dimension by using PCA-SIFT, and find the image which users search for by combining them. To verify efficiency of the proposed method, we compare the performance of our approach with that of SIFT and PCA-SIFT by using images with various patterns. We verify that the proposed method shows the best distinction in the case that product labels are not included in images.

Mobile Camera-Based Positioning Method by Applying Landmark Corner Extraction (랜드마크 코너 추출을 적용한 모바일 카메라 기반 위치결정 기법)

  • Yoo Jin Lee;Wansang Yoon;Sooahm Rhee
    • Korean Journal of Remote Sensing
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    • v.39 no.6_1
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    • pp.1309-1320
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    • 2023
  • The technological development and popularization of mobile devices have developed so that users can check their location anywhere and use the Internet. However, in the case of indoors, the Internet can be used smoothly, but the global positioning system (GPS) function is difficult to use. There is an increasing need to provide real-time location information in shaded areas where GPS is not received, such as department stores, museums, conference halls, schools, and tunnels, which are indoor public places. Accordingly, research on the recent indoor positioning technology based on light detection and ranging (LiDAR) equipment is increasing to build a landmark database. Focusing on the accessibility of building a landmark database, this study attempted to develop a technique for estimating the user's location by using a single image taken of a landmark based on a mobile device and the landmark database information constructed in advance. First, a landmark database was constructed. In order to estimate the user's location only with the mobile image photographing the landmark, it is essential to detect the landmark from the mobile image, and to acquire the ground coordinates of the points with fixed characteristics from the detected landmark. In the second step, by applying the bag of words (BoW) image search technology, the landmark photographed by the mobile image among the landmark database was searched up to a similar 4th place. In the third step, one of the four candidate landmarks searched through the scale invariant feature transform (SIFT) feature point extraction technique and Homography random sample consensus(RANSAC) was selected, and at this time, filtering was performed once more based on the number of matching points through threshold setting. In the fourth step, the landmark image was projected onto the mobile image through the Homography matrix between the corresponding landmark and the mobile image to detect the area of the landmark and the corner. Finally, the user's location was estimated through the location estimation technique. As a result of analyzing the performance of the technology, the landmark search performance was measured to be about 86%. As a result of comparing the location estimation result with the user's actual ground coordinate, it was confirmed that it had a horizontal location accuracy of about 0.56 m, and it was confirmed that the user's location could be estimated with a mobile image by constructing a landmark database without separate expensive equipment.

Spatial Information Search Features Shown in Eye Fixations and Saccades (시선의 고정과 도약에 나타난 공간정보 탐색 특성)

  • Kim, Jong-Ha
    • Korean Institute of Interior Design Journal
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    • v.26 no.2
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    • pp.22-32
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    • 2017
  • This research is to analyze the spatial information search features which shown by Eye fixation and movement and conducted eye tracking experiment for targeting sports shop spatial images which it are same but looks different. This is able to find out the eye movement feature according to placement of goods from the eye movement and movement distance of spatial visitor, and the result can be defined as following. First, the whole original-reverse left / right images have a higher number of observations in the [IN] area than in the [OUT] area. This is because after eye taking high observations in LA area of [IN] have been jump-over [OUT], performed search activities in low eye fixation without high eye fixation. Second, there was a difference in the frequency of the observation data as the composition of the images changed. The original image has been often fixed the eyes in LA area, and the one that has been observed for a long time is reverse left / right image. Also, fixation point was shown higher at the reverse left / right image as jump-over from [OUT] area to [IN] area. If LA area seen as reverse left / right image, it is located in right-hand side. The case where the dominant area is on the right side has a characteristic that the eye fixation is longer. This can be understand that the arrangement of products for attract the customer's attention in the commercial space might be more effective when it is on the right side. Third, the moving distance(IN ${\rightarrow}$ OUT) of the sight pointed to external from LA area was long in the both original-reverse left / right images, but it is no relation with search direction([IN${\rightarrow}$OUT] [IN${\rightarrow}$OUT]) of the sight. In other words, the sight that entered in LA area can be seen as visual perception activity for re-searching after big jump-over, in the case go in to outward (OUT area) after searching for more than certain time. The fact that the moving distance of eye is relatively short in the [IN ${\rightarrow}$ OUT] process considered as that the gaze that stays outside the LA area naturally enters in to LA area.

Area based image matching with MOC-NA imagery (MOC-NA 영상의 영역기준 영상정합)

  • Youn, Jun-Hee;Park, Choung-Hwan
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.28 no.4
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    • pp.463-469
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    • 2010
  • Since MOLA(Mars Orbiter Laser Altimeter) data, which provides altimetry data for Mars, does not cover the whole Mars area, image matching with MOC imagery should be implemented for the generation of DEM. However, automatic image matching is difficult because of insufficient features and low contrast. In this paper, we present the area based semi-automatic image matching algorithm with MOC-NA(Mars Orbiter Camera ? Narrow Angle) imagery. To accomplish this, seed points describing conjugate points are manually added for the stereo imagery, and interesting points are automatically produced by using such seed points. Produced interesting points being used as initial conjugate points, area based image matching is implemented. For the points which fail to match, the locations of initial conjugate points are recalculated by using matched six points and image matching process is re-implemented. The quality assessment by reversing the role of target and search image shows 97.5 % of points were laid within one pixel absolute difference.

Keyword Spotting on Hangul Document Images Using Character Feature Models (문자 별 특징 모델을 이용한 한글 문서 영상에서 키워드 검색)

  • Park, Sang-Cheol;Kim, Soo-Hyung;Choi, Deok-Jai
    • The KIPS Transactions:PartB
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    • v.12B no.5 s.101
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    • pp.521-526
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    • 2005
  • In this Paper, we propose a keyword spotting system as an alternative to searching system for poor quality Korean document images and compare the Proposed system with an OCR-based document retrieval system. The system is composed of character segmentation, feature extraction for the query keyword, and word-to-word matching. In the character segmentation step, we propose an effective method to remove the connectivity between adjacent characters and a character segmentation method by making the variance of character widths minimum. In the query creation step, feature vector for the query is constructed by a combination of a character model by typeface. In the matching step, word-to-word matching is applied base on a character-to-character matching. We demonstrated that the proposed keyword spotting system is more efficient than the OCR-based one to search a keyword on the Korean document images, especially when the quality of documents is quite poor and point size is small.

Region Based Image Similarity Search using Multi-point Relevance Feedback (다중점 적합성 피드백방법을 이용한 영역기반 이미지 유사성 검색)

  • Kim, Deok-Hwan;Lee, Ju-Hong;Song, Jae-Won
    • The KIPS Transactions:PartD
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    • v.13D no.7 s.110
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    • pp.857-866
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    • 2006
  • Performance of an image retrieval system is usually very low because of the semantic gap between the low level feature and the high level concept in a query image. Semantically relevant images may exhibit very different visual characteristics, and may be scattered in several clusters. In this paper, we propose a content based image rertrieval approach which combines region based image retrieval and a new relevance feedback method using adaptive clustering together. Our main goal is finding semantically related clusters to narrow down the semantic gap. Our method consists of region based clustering processes and cluster-merging process. All segmented regions of relevant images are organized into semantically related hierarchical clusters, and clusters are merged by finding the number of the latent clusters. This method, in the cluster-merging process, applies r: using v principal components instead of classical Hotelling's $T_v^2$ [1] to find the unknown number of clusters and resolve the singularity problem in high dimensions and demonstrate that there is little difference between the performance of $T^2$ and that of $T_v^2$. Experiments have demonstrated that the proposed approach is effective in improving the performance of an image retrieval system.

An Analysis of Science Magazine in the View of Infographic (인포그래픽 관점을 이용한 과학 잡지 분석)

  • Jeon, Seongsoo;Jung, Jinkyu;Park, Jong-Ho
    • Journal of The Korean Association For Science Education
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    • v.34 no.6
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    • pp.601-611
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    • 2014
  • The purpose of this study is to analyze the Korean science magazine, Science Donga providing scientific facts, phenomenons, and issues with infographic for the readers by time series analysis and to search for the application of infographic on the science education. The criteria for the infographic analysis of Science Donga consisted of three categories such as storytelling type, visual perception, and framework level because infographic presents complex information quickly and clearly by integrating various images, words, and graphics. We found that the articles emphasized by including image about science issue have been published from 1986 to 2014. Particularly, after 2008, the articles including infographic sharply rose. So we set up 2008 as $T_c$(Critical time point). The articles including infographic after 2008 have been more variously distributed and frequently used in storytelling types category such as location, time, number, connection, function, and process based infographic, in visual perception of Gestalt Theory such as proximity, similarity, continuation, and closure than before 2008. Lastly, in framework level category, location, time, number, and process based infographic mainly had total range level but function and connection based infographic changed in the framework level. The three features about storytelling type, visual perception, framework level are important changes to influence $T_c$ in the infographic analysis about Science Donga. Through the results of this study, we analyzed the feature of change on infographic from 1986 to 2014. Thus, we hope that the results suggest a basic criteria for making materials including infographic in science education.