• Title/Summary/Keyword: Corner feature

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Object Retrieval Using the Corners Area Variability Based on Correlogram (코너영역 분산치 기반 코렐로그램을 이용한 형태검출)

  • An, Young-Eun;Lee, Ji-Min;Yang, Won-Ii;Choi, Young-Il;Chang, Min-Hyuk
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.11 no.6
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    • pp.283-288
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    • 2011
  • This paper have proposed an object retrieval using the corners area variability based on correlogram. The proposed algorithm is processed as follows. First, the corner points of the object in an image are extracted and then the feature vectors are obtained. It are rearranged according to the number dimension and consist of sequence vectors. And the similarity based on the maximum of sequence vectors is measured. The proposed technique is invariant to the rotation or the transfer of the objects and more efficient in case that the objects present simple structure. In simulation that use Wang's database, the method presents that the recall property is improved by 0.03% and more than the standard corner patch histogram.

Video Scene Detection using Shot Clustering based on Visual Features (시각적 특징을 기반한 샷 클러스터링을 통한 비디오 씬 탐지 기법)

  • Shin, Dong-Wook;Kim, Tae-Hwan;Choi, Joong-Min
    • Journal of Intelligence and Information Systems
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    • v.18 no.2
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    • pp.47-60
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    • 2012
  • Video data comes in the form of the unstructured and the complex structure. As the importance of efficient management and retrieval for video data increases, studies on the video parsing based on the visual features contained in the video contents are researched to reconstruct video data as the meaningful structure. The early studies on video parsing are focused on splitting video data into shots, but detecting the shot boundary defined with the physical boundary does not cosider the semantic association of video data. Recently, studies on structuralizing video shots having the semantic association to the video scene defined with the semantic boundary by utilizing clustering methods are actively progressed. Previous studies on detecting the video scene try to detect video scenes by utilizing clustering algorithms based on the similarity measure between video shots mainly depended on color features. However, the correct identification of a video shot or scene and the detection of the gradual transitions such as dissolve, fade and wipe are difficult because color features of video data contain a noise and are abruptly changed due to the intervention of an unexpected object. In this paper, to solve these problems, we propose the Scene Detector by using Color histogram, corner Edge and Object color histogram (SDCEO) that clusters similar shots organizing same event based on visual features including the color histogram, the corner edge and the object color histogram to detect video scenes. The SDCEO is worthy of notice in a sense that it uses the edge feature with the color feature, and as a result, it effectively detects the gradual transitions as well as the abrupt transitions. The SDCEO consists of the Shot Bound Identifier and the Video Scene Detector. The Shot Bound Identifier is comprised of the Color Histogram Analysis step and the Corner Edge Analysis step. In the Color Histogram Analysis step, SDCEO uses the color histogram feature to organizing shot boundaries. The color histogram, recording the percentage of each quantized color among all pixels in a frame, are chosen for their good performance, as also reported in other work of content-based image and video analysis. To organize shot boundaries, SDCEO joins associated sequential frames into shot boundaries by measuring the similarity of the color histogram between frames. In the Corner Edge Analysis step, SDCEO identifies the final shot boundaries by using the corner edge feature. SDCEO detect associated shot boundaries comparing the corner edge feature between the last frame of previous shot boundary and the first frame of next shot boundary. In the Key-frame Extraction step, SDCEO compares each frame with all frames and measures the similarity by using histogram euclidean distance, and then select the frame the most similar with all frames contained in same shot boundary as the key-frame. Video Scene Detector clusters associated shots organizing same event by utilizing the hierarchical agglomerative clustering method based on the visual features including the color histogram and the object color histogram. After detecting video scenes, SDCEO organizes final video scene by repetitive clustering until the simiarity distance between shot boundaries less than the threshold h. In this paper, we construct the prototype of SDCEO and experiments are carried out with the baseline data that are manually constructed, and the experimental results that the precision of shot boundary detection is 93.3% and the precision of video scene detection is 83.3% are satisfactory.

Robust Extraction of Facial Features under Illumination Variations (조명 변화에 견고한 얼굴 특징 추출)

  • Jung Sung-Tae
    • Journal of the Korea Society of Computer and Information
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    • v.10 no.6 s.38
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    • pp.1-8
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    • 2005
  • Facial analysis is used in many applications like face recognition systems, human-computer interface through head movements or facial expressions, model based coding, or virtual reality. In all these applications a very precise extraction of facial feature points are necessary. In this paper we presents a method for automatic extraction of the facial features Points such as mouth corners, eye corners, eyebrow corners. First, face region is detected by AdaBoost-based object detection algorithm. Then a combination of three kinds of feature energy for facial features are computed; valley energy, intensity energy and edge energy. After feature area are detected by searching horizontal rectangles which has high feature energy. Finally, a corner detection algorithm is applied on the end region of each feature area. Because we integrate three feature energy and the suggested estimation method for valley energy and intensity energy are adaptive to the illumination change, the proposed feature extraction method is robust under various conditions.

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Multi-resolution Corner Detection for Stereo Computer Vision (스테레오 비젼을 위한 다해상도 코너 검출)

  • 정정훈;정윤용;홍현기;조청운;백준기;최종수
    • Proceedings of the IEEK Conference
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    • 2002.06d
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    • pp.339-342
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    • 2002
  • The feature points in the uncalibrated stereo vision should represent all the characteristics of an image in multiple resolution, have high precision, and have the robustness against mismatching. This paper proposed an algorithm which detects the corner points in multi-resolution for stereo computer vision. The algorithm has sub-pixel precision, rejects the mismatched points, and corrects the lens distortion. We show the performance of the algorithm by estimating the homography with it.

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Effect of Calcium Carbonate on Properties of Paper in Alkali Paper Masking (중성초지에서 탄산칼슘의 성질이 종이의 물성에 미치는 영향)

  • 신종순
    • Journal of the Korean Graphic Arts Communication Society
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    • v.8 no.1
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    • pp.71-87
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    • 1990
  • This paper presents a simple algorithm to obtain three dimensional information of an object. In the preprocessing of the stereo matching,feature point informations of stero image must be less sensitive to noise and well liked the correspondance problem. This paper described a simple technique of struture feature extraction of 3-D object and used edge-end point expanding method for unconnected line instade of Hough transform. The feature such as corner point and their angles are used for matching problem. The experimental results show that the described algorithm is a useful method for stereo correspondence problem.

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Extraction of kidney's feature points by SIFT algorithm in ultrasound image (SIFT 알고리즘으로 kidney 특징점 검출)

  • Kim, Sung-Jung;Yoo, JaeChern
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2019.07a
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    • pp.313-314
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    • 2019
  • 본 논문에서는 특징점 검출 알고리즘을 적용하여 ultrasound image에서 특징점을 검출하는 것과 object dectection을 위한 keypoints가 object에 올바르게 위치하는지를 검증하는 실험을 진행한다. 특징점 검출을 위한 알고리즘으로는 Scale Invariant Feature Transform(SIFT)과 Harris corner detection 을 적용하여 검증한다.

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Hierarchical Feature Based Block Motion Estimation for Ultrasound Image Sequences (초음파 영상을 위한 계층적 특징점 기반 블록 움직임 추출)

  • Kim, Baek-Sop;Shin, Seong-Chul
    • Journal of KIISE:Software and Applications
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    • v.33 no.4
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    • pp.402-410
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    • 2006
  • This paper presents a method for feature based block motion estimation that uses multi -resolution image sequences to obtain the panoramic images in the continuous ultrasound image sequences. In the conventional block motion estimation method, the centers of motion estimation blocks are set at the predetermined and equally spaced locations. This requires the large blocks to include at least one feature, which inevitably requires long estimation time. In this paper, we propose an adaptive method which locates the center of the motion estimation blocks at the feature points. This make it possible to reduce the block size while keeping the motion estimation accuracy The Harris-Stephen corner detector is used to get the feature points. The comer points tend to group together, which cause the error in the global motion estimation. In order to distribute the feature points as evenly as Possible, the image is firstly divided into regular subregions, and a strongest corner point is selected as a feature in each subregion. The ultrasound Images contain speckle patterns and noise. In order to reduce the noise artifact and reduce the computational time, the proposed method use the multi-resolution image sequences. The first algorithm estimates the motion in the smoothed low resolution image, and the estimated motion is prolongated to the next higher resolution image. By this way the size of search region can be reduced in the higher resolution image. Experiments were performed on three types of ultrasound image sequences. These were shown that the proposed method reduces both the computational time (from 77ms to 44ms) and the displaced frame difference (from 66.02 to 58.08).

Descended Mouth Corner: An Ignored but Needed Feature of Facial Rejuvenation

  • Vidal, Pedro;Berner, Juan Enrique;Castillo, Pablo;Rochefort, Gunther;Loubies, Rodrigo
    • Archives of Plastic Surgery
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    • v.40 no.6
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    • pp.783-786
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    • 2013
  • For years, the gold standard in facial rejuvenation has been the face lift. However, exploring new, less complex procedures for achieving the same goal is currently drawing interest. Rejuvenation of the perioral area is a difficult task for plastic surgeons because of the minimal effect that face lift procedures have over this region and the lack of published material on the subject. In this article, the descended mouth corner anguloplasty technique is presented. It is a 20-minutes lift technique that can correct this typical feature of the ageing mouth. The authors have treated 71 patients using the technique with consistently good results, with just one requiring revision. They conclude that this procedure by itself and in combination with other small operations or even a full face lift can rejuvenate the ageing face.

Extracting the K-most Critical Paths in Multi-corner Multi-mode for Fast Static Timing Analysis

  • Oh, Deok-Keun;Jin, Myeoung-Woo;Kim, Ju-Ho
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.6
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    • pp.771-780
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    • 2016
  • Detecting a set of longest paths is one of the crucial steps in static timing analysis and optimization. Recently, the process variation during manufacturing affects performance of the circuit design due to nanometer feature size. Measuring the performance of a circuit prior to its fabrication requires a considerable amount of computation time because it requires multi-corner and multi-mode analysis with process variations. An efficient algorithm of detecting the K-most critical paths in multi-corner multi-mode static timing analysis (MCMM STA) is proposed in this paper. The ISCAS'85 benchmark suite using a 32 nm technology is applied to verify the proposed method. The proposed K-most critical paths detection method reduces about 25% of computation time on average.

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.