• Title/Summary/Keyword: Feature Region

Search Result 1,155, Processing Time 0.024 seconds

Robust Feature Extraction and Tracking Algorithm Using 2-dimensional Wavelet Transform (2차원 웨이브릿 변환을 이용한 강건한 특징점 추출 및 추적 알고리즘)

  • Jang, Sung-Kun;Suk, Jung-Youp
    • Proceedings of the IEEK Conference
    • /
    • 2007.07a
    • /
    • pp.405-406
    • /
    • 2007
  • In this paper, we propose feature extraction and tracking algorithm using multi resolution in 2-dimensional wavelet domain. Feature extraction selects feature points using 2-level wavelet transform in interested region. Feature tracking estimates displacement between current frame and next frame based on feature point which is selected feature extraction algorithm. Experimental results show that the proposed algorithm confirmed a better performance than the existing other algorithms.

  • PDF

MULTILAYER SPECTRAL INVERSION OF SOLAR Hα AND CA II 8542 LINE SPECTRA WITH HEIGHT-VARYING ABSORPTION PROFILES

  • Chae, Jongchul;Cho, Kyuhyoun;Kang, Juhyung;Lee, Kyoung-Sun;Kwak, Hannah;Lim, Eun-Kyung
    • Journal of The Korean Astronomical Society
    • /
    • v.54 no.5
    • /
    • pp.139-155
    • /
    • 2021
  • We present an updated version of the multilayer spectral inversion (MLSI) recently proposed as a technique to infer the physical parameters of plasmas in the solar chromosphere from a strong absorption line. In the original MLSI, the absorption profile was constant over each layer of the chromosphere, whereas the source function was allowed to vary with optical depth. In our updated MLSI, the absorption profile is allowed to vary with optical depth in each layer and kept continuous at the interface of two adjacent layers. We also propose a new set of physical requirements for the parameters useful in the constrained model fitting. We apply this updated MLSI to two sets of Hα and Ca II line spectral data taken by the Fast Imaging Solar Spectrograph (FISS) from a quiet region and an active region, respectively. We find that the new version of the MLSI satisfactorily fits most of the observed line profiles of various features, including a network feature, an internetwork feature, a mottle feature in a quiet region, and a plage feature, a superpenumbral fibril, an umbral feature, and a fast downflow feature in an active region. The MLSI can also yield physically reasonable estimates of hydrogen temperature and nonthermal speed as well as Doppler velocities at different atmospheric levels. We conclude that the MLSI is a very useful tool to analyze the Hα line and the Ca II 8542 line spectral daya, and will promote the investigation of physical processes occurring in the solar photosphere and chromosphere.

Spectral Pattern Based Robust Speech Endpoint Detection in Noisy Environments (스펙트럼 패턴 기반의 잡음 환경에 강인한 음성의 끝점 검출 기법)

  • Park, Jin-Soo;Lee, Yoon-Jae;Lee, In-Ho;Ko, Han-Seok
    • Phonetics and Speech Sciences
    • /
    • v.1 no.4
    • /
    • pp.111-117
    • /
    • 2009
  • In this paper, a new speech endpoint detector in noisy environment is proposed. According to the previous research, the energy feature in the speech region is easily distinguished from that in the speech absent region. In conventional method, the endpoint can be found by applying the edge detection filter that finds the abrupt changing point in feature domain. However, since the frame energy feature is unstable in noisy environment, the accurate edge detection is not possible. Therefore, in this paper, the novel feature extraction method based on spectrum envelop pattern is proposed. Then, the edge detection filter is applied to the proposed feature for detection of the endpoint. The experiments are performed in the car noise environment and a substantial improvement was obtained over the conventional method.

  • PDF

A Study on Segmentation of Uterine Cervical Pap-Smears Images Using Neural Networks (신경 회로망을 이용한 자궁 경부 세포진 영상의 영역 분할에 관한 연구)

  • 김선아;김백섭
    • Journal of Biomedical Engineering Research
    • /
    • v.22 no.3
    • /
    • pp.231-239
    • /
    • 2001
  • This paper proposes a region segmenting method for the Pap-smear image. The proposed method uses a pixel classifier based on neural network, which consists of four stages : preprocessing, feature extraction, region segmentation and postprocessing. In the preprocessing stage, brightness value is normalized by histogram stretching. In the feature extraction stage, total 36 features are extracted from $3{\times}3$ or $5{\times}5$ window. In the region segmentation stage, each pixel which is associated with 36 features, is classified into 3 groups : nucleus, cytoplasm and background. The backpropagation network is used for classification. In the postprocessing stage, the pixel, which have been rejected by the above classifier, are re-classified by the relaxation algorithm. It has been shown experimentally that the proposed method finds the nucleus region accurately and it can find the cytoplasm region too.

  • PDF

Real-time Pupil Detection Using Local Binarization (지역적 이진화를 이용한 실시간 눈동자 검출)

  • Kim, Min-ha;Yeo, Jae-Yun;Cha, Eui-young
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2012.10a
    • /
    • pp.75-77
    • /
    • 2012
  • In this paper, We proposed that real-time pupil detection using local binarization at each region of eyes in image. In image obtained a single low-resolution web-camera, we detect a region of face using haar-like feature and then detect each region of eyes depending upon the rate of width and height of region of face respectively. In each region of eyes, we detect the pupil after local preprocessing and binarizing. This pupil detection can be variously used for HCI(Human-Computer Interface) systems.

  • PDF

Region of Interest Detection Based on Visual Attention and Threshold Segmentation in High Spatial Resolution Remote Sensing Images

  • Zhang, Libao;Li, Hao
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.7 no.8
    • /
    • pp.1843-1859
    • /
    • 2013
  • The continuous increase of the spatial resolution of remote sensing images brings great challenge to image analysis and processing. Traditional prior knowledge-based region detection and target recognition algorithms for processing high resolution remote sensing images generally employ a global searching solution, which results in prohibitive computational complexity. In this paper, a more efficient region of interest (ROI) detection algorithm based on visual attention and threshold segmentation (VA-TS) is proposed, wherein a visual attention mechanism is used to eliminate image segmentation and feature detection to the entire image. The input image is subsampled to decrease the amount of data and the discrete moment transform (DMT) feature is extracted to provide a finer description of the edges. The feature maps are combined with weights according to the amount of the "strong points" and the "salient points". A threshold segmentation strategy is employed to obtain more accurate region of interest shape information with the very low computational complexity. Experimental statistics have shown that the proposed algorithm is computational efficient and provide more visually accurate detection results. The calculation time is only about 0.7% of the traditional Itti's model.

Method of Human Detection using Edge Symmetry and Feature Vector (에지 대칭과 특징 벡터를 이용한 사람 검출 방법)

  • Byun, Oh-Sung
    • Journal of the Korea Society of Computer and Information
    • /
    • v.16 no.8
    • /
    • pp.57-66
    • /
    • 2011
  • In this paper, it is proposed for algorithm to detect human efficiently using a edge symmetry and gradient directional characteristics in realtime by the feature extraction in a single input image. Proposed algorithm is composed of three stages, preprocessing, region partition of human candidates, verification of candidate regions. Here, preprocessing stage is strong the image regardless of the intensity and brightness of surrounding environment, also detects a contour with characteristics of human as considering the shape features size and the condition of human for characteristic of human. And stage for region partition of human candidates has separated the region with edge symmetry for human and size in the detected contour, also divided 1st candidates region with applying the adaboost algorithm. Finally, the candidate region verification stage makes excellent the performance for the false detection by verifying the candidate region using feature vector of a gradient for divided local area and classifier. The results of the simulations, which is applying the proposed algorithm, the processing speed of the proposed algorithms is improved approximately 1.7 times, also, the FNR(False Negative Rate) is confirmed to be better 3% than the conventional algorithm which is a single structure algorithm.

Classification of Feature Points Required for Multi-Frame Based Building Recognition (멀티 프레임 기반 건물 인식에 필요한 특징점 분류)

  • Park, Si-young;An, Ha-eun;Lee, Gyu-cheol;Yoo, Ji-sang
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.41 no.3
    • /
    • pp.317-327
    • /
    • 2016
  • The extraction of significant feature points from a video is directly associated with the suggested method's function. In particular, the occlusion regions in trees or people, or feature points extracted from the background and not from objects such as the sky or mountains are insignificant and can become the cause of undermined matching or recognition function. This paper classifies the feature points required for building recognition by using multi-frames in order to improve the recognition function(algorithm). First, through SIFT(scale invariant feature transform), the primary feature points are extracted and the mismatching feature points are removed. To categorize the feature points in occlusion regions, RANSAC(random sample consensus) is applied. Since the classified feature points were acquired through the matching method, for one feature point there are multiple descriptors and therefore a process that compiles all of them is also suggested. Experiments have verified that the suggested method is competent in its algorithm.

Feature Extraction on a Periocular Region and Person Authentication Using a ResNet Model (ResNet 모델을 이용한 눈 주변 영역의 특징 추출 및 개인 인증)

  • Kim, Min-Ki
    • Journal of Korea Multimedia Society
    • /
    • v.22 no.12
    • /
    • pp.1347-1355
    • /
    • 2019
  • Deep learning approach based on convolution neural network (CNN) has extensively studied in the field of computer vision. However, periocular feature extraction using CNN was not well studied because it is practically impossible to collect large volume of biometric data. This study uses the ResNet model which was trained with the ImageNet dataset. To overcome the problem of insufficient training data, we focused on the training of multi-layer perception (MLP) having simple structure rather than training the CNN having complex structure. It first extracts features using the pretrained ResNet model and reduces the feature dimension by principle component analysis (PCA), then trains a MLP classifier. Experimental results with the public periocular dataset UBIPr show that the proposed method is effective in person authentication using periocular region. Especially it has the advantage which can be directly applied for other biometric traits.

SIFT-based Stereo Matching to Compensate Occluded Regions and Remove False Matching for 3D Reconstruction

  • Shin, Do-Kyung;Lee, Jeong-Ho;Moon, Young-Shik
    • Proceedings of the Korean Society of Broadcast Engineers Conference
    • /
    • 2009.01a
    • /
    • pp.418-422
    • /
    • 2009
  • Generally, algorithms for generating disparity maps can be clssified into two categories: region-based method and feature-based method. The main focus of this research is to generate a disparity map with an accuracy depth information for 3-dimensional reconstructing. Basically, the region-based method and the feature-based method are simultaneously included in the proposed algorithm, so that the existing problems including false matching and occlusion can be effectively solved. As a region-based method, regions of false matching are extracted by the proposed MMAD(Modified Mean of Absolute Differences) algorithm which is a modification of the existing MAD(Mean of Absolute Differences) algorithm. As a feature-based method, the proposed method eliminates false matching errors by calculating the vector with SIFT and compensates the occluded regions by using a pair of adjacent SIFT matching points, so that the errors are reduced and the disparity map becomes more accurate.

  • PDF