• Title/Summary/Keyword: Blob

Search Result 146, Processing Time 0.024 seconds

Performance Improvement of Human Detection in Thermal Images using Principal Component Analysis and Blob Clustering (주성분 분석과 Blob 군집화를 이용한 열화상 사람 검출 시스템의 성능 향상)

  • Jo, Ahra;Park, Jeong-Sik;Seo, Yong-Ho;Jang, Gil-Jin
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.13 no.2
    • /
    • pp.157-163
    • /
    • 2013
  • In this paper, we propose a human detection technique using thermal imaging camera. The proposed method is useful at night or rainy weather where a visible light imaging cameras is not able to detect human activities. Under the observation that a human is usually brighter than the background in the thermal images, we estimate the preliminary human regions using the statistical confidence measures in the gray-level, brightness histogram. Afterwards, we applied Gaussian filtering and blob labeling techniques to remove the unwanted noise, and gather the scattered of the pixel distributions and the center of gravities of the blobs. In the final step, we exploit the aspect ratio and the area on the unified object region as well as a number of the principal components extracted from the object region images to determine if the detected object is a human. The experimental results show that the proposed method is effective in environments where visible light cameras are not applicable.

Analysis of Visible Light Communication Module Degraded by High Dose-Rate Gamma Irradiation using Thermal Infrared Image (적외선 열영상을 이용한 가시광 통신모듈의 고선량 감마선조사에 따른 열화 분석)

  • Cho, Jai-Wan;Hong, Seok-Boong;Koo, In-Soo
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.17 no.12
    • /
    • pp.1203-1209
    • /
    • 2011
  • In this paper, the degradation evaluation method of VLC (Visible Light Communication) wireless module after high dose rate gamma-ray irradiation using the thermal infrared camera is proposed. First, the heating characteristics of the active devices embedded in the VLC wireless module during the condition of normal operation is monitored by thermal infrared camera. By the image processing technique, the trends of the intensity of the heat emitted by the active devices are calculated and stored. The feature of the blob area including the area of the active devices in the thermal infrared image is extracted and stored. The feature used in this paper is the mean value of the gray levels in the blob area. The same VLC module has been gamma irradiated at the dose rate of about 4.0 kGy/h during 72 hours up to a total dose of 288 kGy. And then, the heating characteristics of the active devices embedded in the VLC wireless module after high dose gamma ray irradiation is observed by thermal infrared camera. The high dose gamma-ray induced degradation of the active devices embedded in the VLC module was evaluated by comparing the mean value of the blob area to the one of the same blob area of the VLC module before the gamma ray irradiation.

Keypoint-based Fast CU Depth Decision for HEVC Intra Coding (HEVC 인트라 부호화를 위한 특징점 기반의 고속 CU Depth 결정)

  • Kim, Namuk;Lim, Sung-Chang;Ko, Hyunsuk;Jeon, Byeungwoo
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.53 no.2
    • /
    • pp.89-96
    • /
    • 2016
  • The High Efficiency Video Coding (MPEG-H HEVC/ITU-T H.265) is the newest video coding standard which has the quadtree-structured coding unit (CU). The quadtree-structure splits a CU adaptively, and its optimum CU depth can be determined by rate-distortion optimization. Such HEVC encoding requires very high computational complexity for CU depth decision. Motivated that the blob detection, which is a well-known algorithm in computer vision, detects keypoints in pictures and decision of CU depth needs to consider high frequency energy distribution, in this paper, we propose to utilize these keypoints for fast CU depth decision. Experimental results show that 20% encoding time can be saved with only slightly increasing BDBR by 0.45% on all intra case.

Experimental investigation on effect of ion cyclotron resonance heating on density fluctuation in SOL at EAST

  • Li, Y.C.;Li, M.H.;Wang, M.;Liu, L.;Zhang, X.J.;Qin, C.M.;Wang, Y.F.;Wu, C.B.;Liu, L.N.;Xu, J.C.;Ding, B.J.;Lin, X.D.;Shan, J.F.;Liu, F.K.;Zhao, Y.P.;Zhang, T.;Gao, X.
    • Nuclear Engineering and Technology
    • /
    • v.54 no.1
    • /
    • pp.207-219
    • /
    • 2022
  • The suppression of high-intensity blob structures in the scrape-off layer (SOL) by ion-cyclotron range of frequencies (ICRF) power, leading to a decrease in the turbulent fluctuation level, is observed first in the Experimental Advanced Superconducting Tokamak (EAST) experiment. This suppression effect from ICRF power injection is global in the whole SOL at EAST, i.e. blob structures both in the regions that are magnetically connected to the active ICRF launcher and in the regions that are not connected to the active ICRF launcher could be suppressed by ICRF power. However, more ICRF power is required to reach the full blob structure suppression effect in the regions that are magnetically unconnected to the active launcher than in the regions that are magnetically connected to the active launcher. Studies show that a possible reason for the blob suppression could be the enhanced Er × B shear flow in the SOL, which is supported by the shaper radial gradient in the floating potential profiles sensed by the divertor probe arrays with increasing ICRF power. The local RF wave power unabsorbed by the core plasma is responsible for the modification of potential profiles in the SOL regions.

The Development of Vehicle Counting System at Intersection Using Mean Shift (Mean Shift를 이용한 교차로 교통량 측정 시스템 개발)

  • Chun, In-Gook
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.7 no.3
    • /
    • pp.38-47
    • /
    • 2008
  • A vehicle counting system at intersection is designed and implemented using analyzing a video stream from a camera. To separate foreground image from background, we compare three different methods, among which Li's method is chosen. Blobs are extracted from the foreground image using connected component analysis and the blobs are tracked by a blob tracker, frame by frame. The primary tracker use only the size and location of blob in foreground image. If there is a collision between blobs, the mean-shift tracking algorithm based on color distribution of blob is used. The proposed system is tested using real video data at intersection. If some huristics is applied, the system shows a good detection rate and a low error rate.

  • PDF

TFT-LCD Defect Blob Detection based on Sequential Defect Detection Method (순차적 결함 검출 방법에 기반한 TFT-LCD 결함 영역 검출)

  • Lee, Eunyoung;Park, Kil-Houm
    • Journal of Korea Society of Industrial Information Systems
    • /
    • v.20 no.2
    • /
    • pp.73-83
    • /
    • 2015
  • This paper proposes a TFT-LCD defect blob detection algorithm using the sequential defect detection method. First, for every pixel, a defect possibility is determined by the intensity difference and the defect candidates are detected according to the sequential defect detection method. For detected candidate pixels, the defect probability that indicates a potential included in the defect according to the each step. By applying the morphological operation, blobs are comprised of the detected candidates and the defect blobs are detected using the defect possibility of blobs. The validity of the proposed method was demonstrated a simulated image and also then it was tested a real TFT-LCD image. By the experimental results, the proposed method is very effective in TFT-LCD detect detection.

An Improved Cast Shadow Removal in Object Detection (객체검출에서의 개선된 투영 그림자 제거)

  • Nguyen, Thanh Binh;Chung, Sun-Tae;Kim, Yu-Sung;Kim, Jae-Min
    • Proceedings of the Korea Contents Association Conference
    • /
    • 2009.05a
    • /
    • pp.889-894
    • /
    • 2009
  • Accompanied by the rapid development of Computer Vision, Visual surveillance has achieved great evolution with more and more complicated processing. However there are still many problems to be resolved for robust and reliable visual surveillance, and the cast shadow occurring in motion detection process is one of them. Shadow pixels are often misclassified as object pixels so that they cause errors in localization, segmentation, tracking and classification of objects. This paper proposes a novel cast shadow removal method. As opposed to previous conventional methods, which considers pixel properties like intensity properties, color distortion, HSV color system, and etc., the proposed method utilizes observations about edge patterns in the shadow region in the current frame and the corresponding region in the background scene, and applies Laplacian edge detector to the blob regions in the current frame and the background scene. Then, the product of the outcomes of application determines whether the blob pixels in the foreground mask comes from object blob regions or shadow regions. The proposed method is simple but turns out practically very effective for Gaussian Mixture Model, which is verified through experiments.

  • PDF

Digit Segmentation in Digit String Image Using CPgraph (CPgraph를 이용한 숫자열 영상에서 숫자 분할)

  • Oh, Jeong-su
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.23 no.9
    • /
    • pp.1070-1075
    • /
    • 2019
  • In this paper, I propose an algorithm to generate an input digit image for a digit recognition system by detecting a digit string in an image and segmenting the digits constituting the digit string. The proposed algorithm detects blobbed digit string through blob detection, designates a digit string area and corrects digit string skew using the detected blob information. And the proposed algorithm corrects the digit skew and determines the boundary points for the digit segmentation in the corrected digit sequence using three CPgraphs newly defined in this paper. In digit segmentation experiments using the image group including digit strings printed with a range of the font sizes and the image group including handwritten digit strings, the proposed algorithm successfully segments 100% and 90% of the digits in each image group.

Line feature extraction in a noisy image

  • Lee, Joon-Woong;Oh, Hak-Seo;Kweon, In-So
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1996.10a
    • /
    • pp.137-140
    • /
    • 1996
  • Finding line segments in an intensity image has been one of the most fundamental issues in computer vision. In complex scenes, it is hard to detect the locations of point features. Line features are more robust in providing greater positional accuracy. In this paper we present a robust "line features extraction" algorithm which extracts line feature in a single pass without using any assumptions and constraints. Our algorithm consists of five steps: (1) edge scanning, (2) edge normalization, (3) line-blob extraction, (4) line-feature computation, and (5) line linking. By using edge scanning, the computational complexity due to too many edge pixels is drastically reduced. Edge normalization improves the local quantization error induced from the gradient space partitioning and minimizes perturbations on edge orientation. We also analyze the effects of edge processing, and the least squares-based method and the principal axis-based method on the computation of line orientation. We show its efficiency with some real images.al images.

  • PDF

Shape and Motion Visualization of the Left Ventricle using a Dynamic Gaussian Blob Model (동적 가우시안 블럽 모델을 이용한 좌심실의 형태 및 운동 가시화)

  • Choi, Soo-Mi;Kim, Myoung-Hee
    • Journal of KIISE:Computer Systems and Theory
    • /
    • v.27 no.9
    • /
    • pp.768-776
    • /
    • 2000
  • 본 논문에서는 심혈관 조영영상으로부터 좌심실의 형태 및 운동을 가시화하기 위해 기하학적 정보와 물리적 정보를 통합한 동적 가우시안 블럽(dynamic gaussian blob)모델을 개발하였다. 동적 가우시안 블럽 모델은 superellipsoid에 3차원 가우시안 형태함수를 갖는 단일 유한요소를 통합한 것으로, 좌심실에 작용되는 가상적인 힘에 의해 형태를 적하하고, 심박동 전 주기에서의 운동을 추적한다. 또한 벽 운동 정도에 따라 다른 색을 지정하여 볼 수 있도록 함으로써 벽 운동에 이상이 있는 부위를 육안으로 쉽게 판별할 수 있도록 하였다. 이와 같은 좌심실의 동적.색체 가시화는 형태가 변황되는 심장질환이나 허혈이나 심근경색증처럼 심실벽 운동에 이상이 있는 질환의 진단을 도울 수 있다.

  • PDF