• 제목/요약/키워드: Feature representation

검색결과 410건 처리시간 0.027초

특징점 기반의 적응적 얼굴 움직임 분석을 통한 표정 인식 (Feature-Oriented Adaptive Motion Analysis For Recognizing Facial Expression)

  • 노성규;박한훈;신홍창;진윤종;박종일
    • 한국HCI학회:학술대회논문집
    • /
    • 한국HCI학회 2007년도 학술대회 1부
    • /
    • pp.667-674
    • /
    • 2007
  • Facial expressions provide significant clues about one's emotional state; however, it always has been a great challenge for machine to recognize facial expressions effectively and reliably. In this paper, we report a method of feature-based adaptive motion energy analysis for recognizing facial expression. Our method optimizes the information gain heuristics of ID3 tree and introduces new approaches on (1) facial feature representation, (2) facial feature extraction, and (3) facial feature classification. We use minimal reasonable facial features, suggested by the information gain heuristics of ID3 tree, to represent the geometric face model. For the feature extraction, our method proceeds as follows. Features are first detected and then carefully "selected." Feature "selection" is finding the features with high variability for differentiating features with high variability from the ones with low variability, to effectively estimate the feature's motion pattern. For each facial feature, motion analysis is performed adaptively. That is, each facial feature's motion pattern (from the neutral face to the expressed face) is estimated based on its variability. After the feature extraction is done, the facial expression is classified using the ID3 tree (which is built from the 1728 possible facial expressions) and the test images from the JAFFE database. The proposed method excels and overcomes the problems aroused by previous methods. First of all, it is simple but effective. Our method effectively and reliably estimates the expressive facial features by differentiating features with high variability from the ones with low variability. Second, it is fast by avoiding complicated or time-consuming computations. Rather, it exploits few selected expressive features' motion energy values (acquired from intensity-based threshold). Lastly, our method gives reliable recognition rates with overall recognition rate of 77%. The effectiveness of the proposed method will be demonstrated from the experimental results.

  • PDF

지도 일반화에 따른 단순화 알고리즘의 평가에 관한 연구 (A Study on the Evaluation of Simplification Algorithms Based on Map Generalization)

  • 김감래;이호남;박인해
    • 한국측량학회지
    • /
    • 제10권2호
    • /
    • pp.63-71
    • /
    • 1992
  • 디지탈 지도 데이타베이스는 다중 축적의 개념을 포함하여 여러 가지 목적을 두고 제작되며 단일 축적으로만 사용하기 위해 Base Map을 구축하는 사례는 극히 보기 드믄 현상이라고 할 수 있다. 따라서 지도의 일반화와 다중표현에 대한 Line의 단순화 처리에 있어서 가장 중요한 문제는 일반화된 그래픽 데이타의 정확도와 인식도를 모두 부여하기 위해 Base Map 상의 정보를 단순화하기 위해 설정하는 허용범위를 디지틸 화일내에서 Feature의 형태에 따라 수정이 가능하도록 하는 것이다. 본 연구에서는 하나의 디지털 화일내에서 다양한 축척상으로 수행되는 Line의 단순화에 대한 여러가지 알고리즘을 고찰하였으며, 지도의 표현상에 변화를 줄 수 있는 선형성 Feature 별로 축척에 따른 규칙을 설정하였다. 수치화된 line 데이타 사이의 상관성을 분석하기 위하여 2가지 변형량을 측정하여 5가지 알고리즘에 대한 평가를 시도하였다. 데이타의 분석결과 Douglas-Peucker 알고리즘이 단순화 후의 변형량에 있어 가장 작은 영향을 받음을 알 수 있었다. 이러한 연구 결과로부터 디지탈 화일을 소축척으로 표현하기 위해 단순화를 실시할 경우 내부적으로 지니고 있어야 하는 기하학적인 항목으로서 그 크기와 변동량에 대한 수치적인 안을 제시함에 따라 지도의 단순화에 대한 가능성을 입증하였다.

  • PDF

Siamese Network for Learning Robust Feature of Hippocampi

  • Ahmed, Samsuddin;Jung, Ho Yub
    • 스마트미디어저널
    • /
    • 제9권3호
    • /
    • pp.9-17
    • /
    • 2020
  • Hippocampus is a complex brain structure embedded deep into the temporal lobe. Studies have shown that this structure gets affected by neurological and psychiatric disorders and it is a significant landmark for diagnosing neurodegenerative diseases. Hippocampus features play very significant roles in region-of-interest based analysis for disease diagnosis and prognosis. In this study, we have attempted to learn the embeddings of this important biomarker. As conventional metric learning methods for feature embedding is known to lacking in capturing semantic similarity among the data under study, we have trained deep Siamese convolutional neural network for learning metric of the hippocampus. We have exploited Gwangju Alzheimer's and Related Dementia cohort data set in our study. The input to the network was pairs of three-view patches (TVPs) of size 32 × 32 × 3. The positive samples were taken from the vicinity of a specified landmark for the hippocampus and negative samples were taken from random locations of the brain excluding hippocampi regions. We have achieved 98.72% accuracy in verifying hippocampus TVPs.

Chaotic Features for Dynamic Textures Recognition with Group Sparsity Representation

  • Luo, Xinbin;Fu, Shan;Wang, Yong
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제9권11호
    • /
    • pp.4556-4572
    • /
    • 2015
  • Dynamic texture (DT) recognition is a challenging problem in numerous applications. In this study, we propose a new algorithm for DT recognition based on group sparsity structure in conjunction with chaotic feature vector. Bag-of-words model is used to represent each video as a histogram of the chaotic feature vector, which is proposed to capture self-similarity property of the pixel intensity series. The recognition problem is then cast to a group sparsity model, which can be efficiently optimized through alternating direction method of multiplier algorithm. Experimental results show that the proposed method exhibited the best performance among several well-known DT modeling techniques.

SEMANTIC FEATURE DETECTION FOR REAL-TIME IMAGE TRANSMISSION OF SIGN LANGUAGE AND FINGER SPELLING

  • Hou, Jin;Aoki, Yoshinao
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2002년도 ITC-CSCC -3
    • /
    • pp.1662-1665
    • /
    • 2002
  • This paper proposes a novel semantic feature detection (SFD) method for real-time image transmission of sign language and finger spelling. We extract semantic information as an interlingua from input text by natural language processing, and then transmit the semantic feature detection, which actually is a parameterized action representation, to the 3-D articulated humanoid models prepared in each client in remote locations. Once the SFD is received, the virtual human will be animated by the synthesized SFD. The experimental results based on Japanese sign langauge and Chinese sign langauge demonstrate that this algorithm is effective in real-time image delivery of sign language and finger spelling.

  • PDF

CT영상의 3차원 재구성 및 표현에 관한 연구 (A Study on the 3D Reconstruction and Representation of CT Images)

  • 한영환;이응혁
    • 대한의용생체공학회:의공학회지
    • /
    • 제15권2호
    • /
    • pp.201-208
    • /
    • 1994
  • Many three-dimensional object modeling and display methods for computer graphics and computer vision have been developed. Recently, with the help of medical imaging devices such as computerized tomography, magnetic resonance image, etc., some of those object modeling and display methods have been widely used for capturing the shape, structure and other properties of real objects in many medical applications. In this paper, we propose the reconstruction and display method of the three-dimensional object from a series of the cross sectonal image. It is implemented by using the automatic threshold selection method and the contour following algorithm. The combination of curvature and distance, we select feature points. Those feature points are the candidates for the tiling method. As a results, it is proven that this proposed method is very effective and useful in the comprehension of the object's structure. Without the technician's responce, it can be automated.

  • PDF

Deep Convolutional Auto-encoder를 이용한 환경 변화에 강인한 장소 인식 (Condition-invariant Place Recognition Using Deep Convolutional Auto-encoder)

  • 오정현;이범희
    • 로봇학회논문지
    • /
    • 제14권1호
    • /
    • pp.8-13
    • /
    • 2019
  • Visual place recognition is widely researched area in robotics, as it is one of the elemental requirements for autonomous navigation, simultaneous localization and mapping for mobile robots. However, place recognition in changing environment is a challenging problem since a same place look different according to the time, weather, and seasons. This paper presents a feature extraction method using a deep convolutional auto-encoder to recognize places under severe appearance changes. Given database and query image sequences from different environments, the convolutional auto-encoder is trained to predict the images of the desired environment. The training process is performed by minimizing the loss function between the predicted image and the desired image. After finishing the training process, the encoding part of the structure transforms an input image to a low dimensional latent representation, and it can be used as a condition-invariant feature for recognizing places in changing environment. Experiments were conducted to prove the effective of the proposed method, and the results showed that our method outperformed than existing methods.

다성음원 기반 QbSH 시스템을 위한 매칭엔진의 설계 및 구현 (Design and Implementation of Matching Engine for QbSH System Based on Polyphonic Music)

  • 박성주;정광수
    • 한국멀티미디어학회논문지
    • /
    • 제15권1호
    • /
    • pp.18-31
    • /
    • 2012
  • 본 논문은 다성음원에서 추출된 특성정보 기반 QbSH (Query-by-Singing/ Humming) 시스템의 매칭엔진에 대해 제안하였다. 다성음원 기반 QbSH 시스템은 사람의 노래나 허밍에서 추출된 특성정보와 MP3 파일과 같은 다성음원에서 추출된 특성정보를 비교하여, 가장 유사한 음원을 검색하는 시스템이다. 제안된 매칭엔진에는 다성음원에서 특성 추출시 발생하는 오류를 줄이고, 매칭성능을 향상시키기 위해 크로마-스케일 표현기법 (Chroma-Scale Representation), 보상기법 (Compensation) 및 비대칭적 DTW (Asymmetric Dynamic Time Warping) 알고리즘을 적용하였다. 또한 다양한 거리 함수 (Distance Metric)를 적용하여 매칭엔진의 성능향상을 확인하였다. 1,000개의 허밍 질의와 450곡의 다성음원 데이터베이스를 기반으로 제안한 QbSH 시스템의 성능 실험을 수행하다. 성능 평가를 통해 제안한 QbSH 시스템이 MRR (Mean Reciprocal Rank) 0.718의 정확도를 가지는 것으로 확인되었다.

단어 의미와 자질 거울 모델을 이용한 단어 임베딩 (A Word Embedding used Word Sense and Feature Mirror Model)

  • 이주상;신준철;옥철영
    • 정보과학회 컴퓨팅의 실제 논문지
    • /
    • 제23권4호
    • /
    • pp.226-231
    • /
    • 2017
  • 단어 표현은 기계학습을 사용하는 자연어 처리 분야에서 중요하다. 단어 표현은 단어를 텍스트가 아닌 컴퓨터가 분별할 수 있는 심볼로 표현하는 방법이다. 기존 단어 임베딩은 대량의 말뭉치를 이용하여 문장에서 학습할 단어의 주변 단어를 이용하여 학습한다. 하지만 말뭉치 기반의 단어 임베딩은 단어의 등장 빈도수나 학습할 단어의 수를 늘리기 위해서는 많은 양의 말뭉치를 필요로 한다. 본 논문에서는 말뭉치 기반이 아닌 단어의 뜻풀이와 단어의 의미 관계(상위어, 반의어)를 이용하며 기존 Word2Vec의 Skip-Gram을 변형한 자질거울모델을 사용하여 단어를 벡터로 표현하는 방법을 제시한다. 기존 Word2Vec에 비해 적은 데이터로 많은 단어들을 벡터로 표현 가능하였으며 의미적으로 유사한 단어들이 비슷한 벡터를 형성하는 것을 확인할 수 있다. 그리고 반의어 관계에 있는 두 단어의 벡터가 구분되는 것을 확인할 수 있다.

뉴럴 네트워크 알고리즘을 이용한 비드 가시화 (Using Neural Network Algorithm for Bead Visualization)

  • 구창대;양형석;김중영;신상호
    • Journal of Welding and Joining
    • /
    • 제31권5호
    • /
    • pp.35-40
    • /
    • 2013
  • In this paper, we propose the Tangible Virtual Reality Representation Method to using haptic device and feature to morphology of created bead from Flux Cored Arc Welding. The virtual reality was started to rising for reduce to consumable materials and welding training risk. And, we will expected maximize virtual reality from virtual welding training. In this paper proposed method is get the database to changing the input factor such as work angle, travelling angle, speed, CTWD. And, it is visualization to bead from extract to optimal morphological feature information to using the Neural Network algorithm. The database was building without error to extract data from automatic robot welder. Also, the Neural Network algorithm was set a dataset of the highest accuracy from verification process in many times. The bead was created in virtual reality from extract to morphological feature information. We were implementation to final shape of bead and overlapped in process by time to using bead generation algorithm and calibration algorithm for generate to same bead shape to real database in process of generating bead. The best advantage of virtual welding training, it can be get the many data to training evaluation. In this paper, we were representation bead to similar shape from generated bead to Flux Cored Arc Welding. Therefore, we were reduce the gap to virtual welding training and real welding training. In addition, we were confirmed be able to maximize the performance of education from more effective evaluation system.