• 제목/요약/키워드: Histogram of Gradient

검색결과 116건 처리시간 0.167초

Two Wheeler Recognition Using the Correlation Coefficient for Histogram of Oriented Gradients to Apply Intelligent Wheelchair (지능형 휠체어 적용을 위한 기울기 히스토그램의 상관계수를 이용한 도로위의 이륜차 인식)

  • Kim, Bum-Koog;Park, Sang-Hee;Lee, Yeung-Hak;Lee, Gang-Hwa
    • Journal of Biomedical Engineering Research
    • /
    • 제32권4호
    • /
    • pp.336-344
    • /
    • 2011
  • This article describes a new recognition algorithm using correlation coefficient for intelligent wheelchair to avoid collision for elderly or disabled people. The correlation coefficient can be used to represent the relationship of two different areas. The algorithm has three steps: Firstly, we extract an edge vector using the Histogram of Oriented Gradients(HOG) which includes gradient information and unique magnitude for each cell. From this result, the correlation coefficients are calculated between one cell and others. Secondly, correlation coefficients are used as the weighting factors for normalizing the HOG cell. And finally, these features are used to classify or detect variable and complicated shapes of two wheelers using Adaboost algorithm. In this paper, we propose a new feature vectors which is calculated by weighted cell unit to classify with multiple view-based shapes: frontal, rear and side views($60^{\circ}$, $90^{\circ}$ and mixed angle). Our experimental results show that two wheeler detection system based on a proposed approach leads to a higher detection accuracy than the method using traditional features in a similar detection time.

Comparison of plan dosimetry on multi-targeted lung radiotherapy: A phantom-based computational study using IMRT and VMAT

  • Khan, Muhammad Isa;Rehman, Jalil ur;Afzal, Muhammad;Chow, James C.L.
    • Nuclear Engineering and Technology
    • /
    • 제54권10호
    • /
    • pp.3816-3823
    • /
    • 2022
  • This work analyzed the dosimetric difference between the intensity modulated radiotherapy (IMRT), partial/single/double-arc volumetric modulated arc therapy (PA/SA/DA-VMAT) techniques in treatment planning for treating more than one target of lung cancer at different isocenters. IMRT and VMAT plans at different isocenters were created systematically using a Harold heterogeneous lung phantom. The conformity index (CI), homogeneity index (HI), gradient index (GI), dose-volume histogram and mean and maximum dose of the PTV were calculated and analyzed. Furthermore, the dose-volume histogram and mean and maximum doses of the OARs such as right lung, contralateral lung and non GTV were determined from the plans. The IMRT plans showed the superior target dose coverage, higher mean and maximum values than other VMAT techniques. PA-VMAT technique shows more lung sparing and DA-VMAT increases the V5/10/20 values of contralateral lung than other VMAT and IMRT techniques. The IMRT technique achieves highly conformal dose distribution to the target than other VMAT techniques. Comparing to the IMRT plans, the higher V5/10/20 and mean lung dose were observed in the contralateral lung in the DA-VMAT.

Two-wheeler Detection System using Histogram of Oriented Gradients based on Local Correlation Coefficients and Curvature

  • Lee, Yeunghak;Kim, Taesun;Shim, Jaechang
    • Journal of Multimedia Information System
    • /
    • 제2권4호
    • /
    • pp.303-310
    • /
    • 2015
  • Vulnerable road users such as bike, motorcycle, small automobiles, and etc. are easily attacked or threatened with bigger vehicles than them. So this paper suggests a new approach two-wheelers detection system riding on people based on modified histogram of oriented gradients (HOGs) which is weighted by curvature and local correlation coefficient. This correlation coefficient between two variables, in which one is the person riding a bike and other is its background, can represent correlation relation. First, we extract edge vectors using the curvature of Gaussian and Histogram of Oriented Gradients (HOG) which includes gradient information and differential magnitude as cell based. And then, the value, which is calculated by the correlation coefficient between the area of each cell and one of bike, can be used as the weighting factor in process for normalizing the HOG cell. This paper applied the Adaboost algorithm to make a strong classification from weak classification. The experimental results validate the effectiveness of our proposed algorithm show higher than that of the traditional method and under challenging, such as various two-wheeler postures, complex background, and even conclusion.

A Study on Edge Detection using Modified Histogram Equalization (변형된 히스토그램 평활화를 적용한 에지 검출에 관한 연구)

  • Lee, Chang-Young;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • 제19권5호
    • /
    • pp.1221-1227
    • /
    • 2015
  • Edge detection is one of the important technologies to simplify images in the text, lane and object recognition implementation process, and various studies are actively carried out at home and abroad. Existing edge detection methods include a method to detect edge by applying directional gradient masks in spatial space, and a mathematical morphology-based edge detection method. These existing detection methods show insufficient edge detection results in excessively dark or bright images. In this regard, to complement these drawbacks, we proposed an algorithm using the Sobel and histogram equalization among the existing methods.

Deskewing Document Image using the Gradient of the Spaces Between Sentences. (문장 사이의 공백 기울기를 이용한 문서 이미지 기울기 보정)

  • Heo, Woo-hyung;Gu, Eun-jin;Kim, Cheol-ki;Cha, Eui-young
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 한국정보통신학회 2013년도 춘계학술대회
    • /
    • pp.379-381
    • /
    • 2013
  • In this paper, we propose a method to detect the gradient of the spaces between sentences and to deskew in the document image. First, gradient is measured by pixels for spaces between sentences that has been done an edge extraction in document image and then skewed image is corrected by using the value of the gradient which has been measured. Since document image is divided into several areas, it shows a robust processing result by handling the margin, images, and multistage form in the document. Because the proposed method does not use pixel of the character region but use the blank area, degraded document image as well as vivid document image is effectively corrected than conventional method.

  • PDF

Object Cataloging Using Heterogeneous Local Features for Image Retrieval

  • Islam, Mohammad Khairul;Jahan, Farah;Baek, Joong Hwan
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제9권11호
    • /
    • pp.4534-4555
    • /
    • 2015
  • We propose a robust object cataloging method using multiple locally distinct heterogeneous features for aiding image retrieval. Due to challenges such as variations in object size, orientation, illumination etc. object recognition is extraordinarily challenging problem. In these circumstances, we adapt local interest point detection method which locates prototypical local components in object imageries. In each local component, we exploit heterogeneous features such as gradient-weighted orientation histogram, sum of wavelet responses, histograms using different color spaces etc. and combine these features together to describe each component divergently. A global signature is formed by adapting the concept of bag of feature model which counts frequencies of its local components with respect to words in a dictionary. The proposed method demonstrates its excellence in classifying objects in various complex backgrounds. Our proposed local feature shows classification accuracy of 98% while SURF,SIFT, BRISK and FREAK get 81%, 88%, 84% and 87% respectively.

Adaptive Thresholding Method for Edge Detection (윤곽선 검출을 위한 적응적 임계치 결정 방법)

  • 임강모;신창훈;조남형;이주신
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 한국해양정보통신학회 2000년도 춘계종합학술대회
    • /
    • pp.352-355
    • /
    • 2000
  • In this paper, we propose an adaptive thresholding for edge detection. first, we got histograms for background image and image with moving object, respectively. Then we make difference histogram between histograms of background and object image. A thresholding value is decided using gradient of peak to peak in the difference histogram. The experimentation is processed using a moving car in the road. The result is that edge is detected well regardless of the brightness.

  • PDF

Makeup transfer by applying a loss function based on facial segmentation combining edge with color information (에지와 컬러 정보를 결합한 안면 분할 기반의 손실 함수를 적용한 메이크업 변환)

  • Lim, So-hyun;Chun, Jun-chul
    • Journal of Internet Computing and Services
    • /
    • 제23권4호
    • /
    • pp.35-43
    • /
    • 2022
  • Makeup is the most common way to improve a person's appearance. However, since makeup styles are very diverse, there are many time and cost problems for an individual to apply makeup directly to himself/herself.. Accordingly, the need for makeup automation is increasing. Makeup transfer is being studied for makeup automation. Makeup transfer is a field of applying makeup style to a face image without makeup. Makeup transfer can be divided into a traditional image processing-based method and a deep learning-based method. In particular, in deep learning-based methods, many studies based on Generative Adversarial Networks have been performed. However, both methods have disadvantages in that the resulting image is unnatural, the result of makeup conversion is not clear, and it is smeared or heavily influenced by the makeup style face image. In order to express the clear boundary of makeup and to alleviate the influence of makeup style facial images, this study divides the makeup area and calculates the loss function using HoG (Histogram of Gradient). HoG is a method of extracting image features through the size and directionality of edges present in the image. Through this, we propose a makeup transfer network that performs robust learning on edges.By comparing the image generated through the proposed model with the image generated through BeautyGAN used as the base model, it was confirmed that the performance of the model proposed in this study was superior, and the method of using facial information that can be additionally presented as a future study.

Wavelet-Based Edge Detection Using Local Histogram Analysis in Images (영상에서 웨이블렛 기반 로컬 히스토그램 분석을 이용한 에지검출)

  • Park, Min-Joon;Kwon, Min-Jun;Kim, Gi-Hun;Shim, Han-Seul;Kim, Dong-Wook;Lim, Dong-Hoon
    • The Korean Journal of Applied Statistics
    • /
    • 제24권2호
    • /
    • pp.359-371
    • /
    • 2011
  • Edge detection in images is an important step in image segmentation and object recognition as preprocessing for image processing. This paper presents a new edge detection using local histogram analysis based on wavelet transform. In this work, the wavelet transform uses three components (horizontal, vertical and diagonal) to find the magnitude of the gradient vector, instead of the conventional approach in which tw components are used. We compare the magnitude of the gradient vector with the threshold that is obtained from a local histogram analysis to conclude that an edge is present or not. Some experimental results for our edge detector with a Sobel, Canny, Scale Multiplication, and Mallat edge detectors on sample images are given and the performances of these edge detectors are compared in terms of quantitative and qualitative measures. Our detector performs better than the other wavelet-based detectors such as Scale Multiplication and Mallat detectors. Our edge detector also preserves a good performance even if the Sobel and Canny detector are sharply low when the images are highly corrupted.

Card Recognition Using Hierarchical Tree Structure (계층적 트리 구조를 이용한 카드 인식 시스템)

  • Shim, Eun-Ji;Jeon, Moon-Gu
    • Proceedings of the Korean Information Science Society Conference
    • /
    • 한국정보과학회 2012년도 한국컴퓨터종합학술대회논문집 Vol.39 No.1(B)
    • /
    • pp.489-491
    • /
    • 2012
  • 본 논문은 교육용 서비스로 이용 가능한 카드 인식 시스템을 제안한다. 사용자는 자유자재로 카드 등록 및 삭제가 가능하며 카드의 회전 및 크기 변화에도 강건한 인식을 보인다. 본 논문에서는 카드 템플릿의 형태 정보와 Histogram of Oriented Gradients를 특징점으로 이용한다. 또한 최종 분류기에서 계층적인 구조를 적용하여 보다 정확한 카드 검출 및 인식을 제안한다.