• 한국멀티미디어학회논문지
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• 제18권5호
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• pp.610-619
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• 2015

*In this paper, we propose a real-time face tracking system using an adaptive face detector and a tracking algorithm. An image is divided into the regions of background and face candidate by a real-time updated skin color identifying system in order to accurately detect facial features. The facial characteristics are extracted using the five types of simple Haar-like features. The extracted features are reinterpreted by Principal Component Analysis (PCA), and the interpreted principal components are processed by Support Vector Machine (SVM) that classifies into facial and non-facial areas. The movement of the face is traced by Kalman filter and Mean shift, which use the static information of the detected faces and the differences between previous and current frames. The proposed system identifies the initial skin color and updates it through a real-time color detecting system. A similar background color can be removed by updating the skin color. Also, the performance increases up to 20% when the background color is reduced in comparison to extracting features from the entire region. The increased detection rate and speed are acquired by the usage of Kalman filter and Mean shift.

• 인지과학
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• 제11권2호
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• pp.53-58
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• 2000

본 논문은 FCM 군집화 알고리즘을 사용하여 표정영상에서 특징점들을 추출한 후 추출된 특징점으로부터 Gabor 웨이브렛들을 이용하여 표정영상의 국소영역을 복원한다. 얼굴의 특징점 추출은 두단계로 이루어진다. 1단계는 이차원 Gabor 웨이브렛 계수 히스토그램의 평균값을 적용하여 얼굴의 주요 요소성분들의 경계선을 추출한 후, 2단계에서는 추출된 경계선 정보로부터 FCM 군집화 알고리즘을 사용하여 얼굴의 주요 요소성분들의 최종적인 특징점들을 추출한다. 본 연구에서는 FCM 군집화 알고리즘을 이용하여 추출된 적은 수의 특징점들 만으로도 표정영상의 주요 요소들을 복원할 수 있음을 제시한다. 이것은 인간의 얼굴 표정인식 뿐만아니라 물체인식에도 적용되어질 수 있다.

• 한국인터넷방송통신학회논문지
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• 제8권1호
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• pp.25-30
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• 2008

본 논문에서는 인물 이미지를 GIF로 변환 할 시에 색상의 손실을 최대한 줄이기 위한 알고리듬을 제안한다. 손실을 줄이는 방법으로는 Octree Quantization과 살색 검출 mask를 이용한다. 인물이미지의 경우, 살색정보가 이미지의 중요한 부분을 차지하고 있으므로, 살색 영역을 검출 할 수 있는 mask를 생성하여 살색영역과 그 밖의 영역을 분리하고, 분리된 영역별로 Color Quantization을 한다. 제안된 알고리듬을 통하여 24비트 이미지를 GIF로 변환한 결과, 일반적으로 많이 사용하는 이미지 포맷변환 툴을 사용하여 변환한 영상보다 살색 정보의 손실이 최소화됨으로써, 인물이미지의 GIF 변환에 있어 좋은 성능을 보여 준다는 것을 확인할 수 있다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제34권6호
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• pp.494-497
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• 2012

Traumatic lacerations are common in the orofacial region as a result of accidents. Due to the frequent movement of the skin around the mandible, scars in that area are more likely to widen or become hypertrophic. Treatment of facial laceration was performed on three patients and followed by regular check-up. It was discovered that the scars have become hypertrophic, so steroid injections were used. The results were satisfactory with the decrease in sizes and hardnes of the scar. Facial scarring is a particularly distressing phenomenon and has always been a challenge to treat as the scars are more likely to widen or become hyphertrophied due to the frequent movement of the muscle in the facial area. We confirmed that the positive effect of steroid on hypertrophic scars. So, we suggest that proper treatment and periodic follow-up, adjuvant treatments especially steroid injection is necessary in patients with lacerations.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(4)
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• pp.41-44
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• 2000

In this paper, we present an efficient face detection algorithm for locating vertical views of human faces in complex scenes. The algorithm models the distribution of human skin color in YCbCr color space and find various ace candidate regions. Face candidate regions are found by thresholding with predetermined thresholds. For each of these face candidate regions, The sobel edge operator is used to find edge regions. For each edge region, we used an ellipse detection algorithm which is similar to hough transform to refine the candidate region. Finally if a substantial number of he facial features (eye, mouth) are found successfully in the candidate region, we determine he ace candidate region as a face region. e show empirically that the presented algorithm an find the face region very well in the complex scenes.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제35권6호
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• pp.360-367
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• 2013

Purpose: The purpose of this study was to perform three-dimensional (3D) assessment of facial soft tissue in patients with skeletal Class III and mandibular asymmetry after orthognathic surgery. Methods: Samples consisted of 3D facial images obtained from five patients with A point-nasion-B point angle less than 2 degrees, and more than 5 mm of menton deviation. All patients had been treated at Gangneung-Wonju National University Dental Hospital from 2009 to 2012. They had undergone orthognathic surgery of Lefort I, and sagittal split osteotomy for correction of skeletal deformity, and orthodontic treatment. Facial scanning was performed before treatment (T1) and post-surgical orthodontic treatment (T2). Linear and angle variables of soft tissue landmarks, antero-posterior facial depth, and facial volume were measured. Results: No significant differences in width of the alar base, mouth width, and nasal canting were observed between T1 and T2. However, lip deviation, menton deviation, alar canting, lip canting, and menton deviation angle were significantly reduced at T2. Antero-posterior facial depth on the axial plane parallel to the left cheilion was significantly reduced on the deviated side and significantly increased on the non-deviated side at T2. Volume of the lower lateral and lower medial parts of the face was reduced on the deviated side, and volume of upper lateral and lower lateral parts on the non-deviated side was significantly increased at T2. Conclusion: After orthognathic surgery, facial asymmetry of soft tissue was improved following skeletal changes, especially the mandibular region. Although the length of the alar base and mouth width did not change, lip and soft tissue menton were displaced to the medial side after treatment. Facial depth also became symmetric after treatment. Facial volume showed a decrease on the lower part of the deviated side and that on lateral parts of the non-deviated side showed an increase after treatment.

• 한국정보과학회논문지:소프트웨어및응용
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• 제36권2호
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• pp.161-168
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• 2009

본 논문에서는 다양한 장애를 가진 사용자들을 위한 지능형 휠체어의 인터페이스를 제안한다. 제안된 시스템의 주된 목적은 전동휠체어의 조이스틱을 사용하기 힘든 장애인들에게 효율적인 인터페이스를 제공함으로써 그들의 안전한 이동성을 보장하여 독립적인 삶을 이끌어 나갈 수 있도록 하는 것이다. 이를 위해 제안된 시스템은 사용자의 얼굴 기울기를 인식하여 휠체어의 회전을 수행하고 입 모양을 인식하여 휠체어의 전진과 정지를 수행 한다. 이러한 얼굴 특징을 인식하기 위해 제안된 시스템은 얼굴 특징 검출기, 얼굴 특징 인식기, 전환기로 구성된다. 얼굴 특징 검출기는 Adaboost를 이용하여 얼굴 영역을 먼저 검출한 후 에지 정보를 이용하여 입 영역을 검출한다. 검출된 결과들은 얼굴 특징 인식기에저 statistical analysis와 K-means clustering을 이용하여 얼굴 각도와 입 모양을 인식한다. 전환기는 인식된 결과들을 휠체어의 모터를 제어하기 위한 명령어로 변환하여 사용자의 얼굴 및 입의 움직임으로 휠체어를 제어할 수 있도록 한다. 제안된 지능형 휠체어의 효율성을 증명하기 위하여 34명의 사용자를 대상으로 다양한 환경에서 실험한 결과 제안된 시스템은 전동 휠체어의 조이스틱을 사용 할 수 없는 장애인들에게 편리한 이동성을 제공하며, 보다 편리하고 친숙한 인터페이스로 사용 될 수 있음을 보여 주었다.

• Korean Journal of Acupuncture
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• 제19권2호
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• pp.13-33
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• 2002

This study was examined for effects of acupuncture of Zusanli (ST36) on the facial thermography in health subjects. The volunteers who participating in this study had taken rest for 20 - 30 mins in room temperature (23-$25^{\circ}C$) before the examination and informed them what to prohibit smoking, drinking and administration of drug for the previous day. The thermography of face was taken using Infra-Red Imaging System (IR 2000, MEDI-CORE Co., Korea) by time interval of 15 minutes at 15 min before, just before and 15 min after, 30 min after and 45 min after acupuncture stimulation. Acupuncture was applied to the left ST36 for 30 mins. The results showed that acupuncture of ST36 significantly decreased the temperature of all the areas of facial surface comparing to those of control group. Also, it was observed that the quantities of thermal changes following acupuncture of ST36 been increased significantly at the A1, A4, A6, A7 and A9 ROIs (region of interest) comparing that of control group. Observed the thermography classified by ROI, it was clear the fact that acupuncture of ST36 could modulate the specific areas concerning to the facial pathway of Stomach Meridian, because the thermal responses following acupuncture of ST36 were specific at the A1, A2, A5 and A9 ROIs, relatively. These results suggest that acupuncture of ST36 may modulate thermal distributions and changes of facial areas concerned with Stomach Meridian.

• 정보처리학회논문지B
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• 제9B권5호
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• pp.563-570
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• 2002

본 논문은 MPEG4 SNHC의 얼굴 모델 인코딩을 구현하기 위하여 연속된 2차원 영상으로부터 얼굴영역을 검출하고, 얼굴의 특징데이터들을 추출한 후, 얼굴의 3차원 모양 및 움직임 정보를 복원하는 알고리즘과 결과를 제시한다. 얼굴 영역 검출을 위해서 영상의 거리, 피부색상, 움직임 색상정보등을 융합시킨 멀티모달합성의 방법이 사용되었다. 결정된 얼굴영역에서는 MPEG4의 FDP(Face Definition Parameter) 에서 제시된 특징점 위치중 23개의 주요 얼굴 특징점을 추출하며 추출성능을 향상시키기 위하여 GSCD(Generalized Skin Color Distribution), BWCD(Black and White Color Distribution)등의 움직임색상 변환기법과 형태연산 방법이 제시되었다. 추출된 2차원 얼팔 특징점들로부터 얼굴의 3차원 모양, 움직임 정보를 복원하기 위하여 준원근 카메라 모델을 적용하여 SVD(Singular Value Decomposition)에 의한 인수분해연산을 수행하였다. 본 논문에서 제시된 방법들의 성능을 객관적으로 평가하기 위하여 크기와 위치가 알려진 3차원 물체에 대해 실험을 행하였으며, 복원된 얼굴의 움직임 정보는 MPEG4 FAP(Face Animation Parameter)로 변환된 후, 인터넷상에서 확인이 가능한 가상얼굴모델에 인코딩되어 실제 얼굴파 일치하는 모습을 확인하였다.

• Imaging Science in Dentistry
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• 제51권3호
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• pp.279-290
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• 2021

Purpose: Using images in the facial image comparison process poses a challenge for forensic experts due to limitations such as the presence of facial expressions. The aims of this study were to analyze how morphometric changes in the face during a spontaneous smile influence the facial image comparison process and to evaluate the reproducibility of measurements obtained by digital stereophotogrammetry in these situations. Materials and Methods: Three examiners used digital stereophotogrammetry to obtain 3-dimensional images of the faces of 10 female participants(aged between 23 and 45 years). Photographs of the participants' faces were captured with their faces at rest (group 1) and with a spontaneous smile (group 2), resulting in a total of 60 3-dimensional images. The digital stereophotogrammetry device obtained the images with a 3.5-ms capture time, which prevented undesirable movements of the participants. Linear measurements between facial landmarks were made, in units of millimeters, and the data were subjected to multivariate and univariate statistical analyses using Pirouette^® version 4.5 (InfoMetrix Inc., Woodinville, WA, USA) and Microsoft Excel^® (Microsoft Corp., Redmond, WA, USA), respectively. Results: The measurements that most strongly influenced the separation of the groups were related to the labial/buccal region. In general, the data showed low standard deviations, which differed by less than 10% from the measured mean values, demonstrating that the digital stereophotogrammetry technique was reproducible. Conclusion: The impact of spontaneous smiles on the facial image comparison process should be considered, and digital stereophotogrammetry provided good reproducibility.