• Title/Summary/Keyword: shadow feature extraction

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Improved Skin Color Extraction Based on Flood Fill for Face Detection (얼굴 검출을 위한 Flood Fill 기반의 개선된 피부색 추출기법)

  • Lee, Dong Woo;Lee, Sang Hun;Han, Hyun Ho;Chae, Gyoo Soo
    • Journal of the Korea Convergence Society
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    • v.10 no.6
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    • pp.7-14
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    • 2019
  • In this paper, we propose a Cascade Classifier face detection method using the Haar-like feature, which is complemented by the Flood Fill algorithm for lossy areas due to illumination and shadow in YCbCr color space extraction. The Cascade Classifier using Haar-like features can generate noise and loss regions due to lighting, shadow, etc. because skin color extraction using existing YCbCr color space in image only uses threshold value. In order to solve this problem, noise is removed by erosion and expansion calculation, and the loss region is estimated by using the Flood Fill algorithm to estimate the loss region. A threshold value of the YCbCr color space was further allowed for the estimated area. For the remaining loss area, the color was filled in as the average value of the additional allowed areas among the areas estimated above. We extracted faces using Haar-like Cascade Classifier. The accuracy of the proposed method is improved by about 4% and the detection rate of the proposed method is improved by about 2% than that of the Haar-like Cascade Classifier by using only the YCbCr color space.

Crane Monitoring System for Moving Objects in Safety Lines (크레인 안전선 접근 이동 물체 감시 시스템)

  • Chong, Ui-Pil
    • Journal of the Institute of Convergence Signal Processing
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    • v.12 no.4
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    • pp.237-241
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    • 2011
  • Stable operation of an industry crane becomes more important as current industry facilities become larger and operate at higher speeds. This paper proposes implementing a system for monitoring moving objects within safety lines of an industry crane by camera. The cost of implementing such a system is low, since it requires only a webcam and notebook computer. The detection algorithm of moving objects uses the feature extraction method by image differential histograms. The proposed system is robust to variations in the weather and environment. The area of the inside safety lines is considered and shadow removal algorithm is used for good performance of the system. The system is valuable for practical applications in the industry.

Efficient Color Feature Information Extraction Method for Color Histogram-based Image Retrieval (칼라 히스토그램 기반 영상 검색을 위한 효율적인 칼라 특징 정보 추출 기법)

  • 이호영;김영태;김희수;배태면;하영호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.8B
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    • pp.1413-1423
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    • 2000
  • Color distribution is changed according to the variation of illumination position and illumination color. Therefore, even if images are relevant each other, retrieval accuracy is degraded. In this paper, we propose the image retrieval method using color information excluded illumination component. The proposed dynamic range control method removes the shadow region generated by change of illumination position to increase the color discrimination power. To exclude the illuminant color, we use the diffuse reflection component of object and gray world assumption. The experimental results show that the color histogram method using color information excluded illuminant has higher retrieval accuracy than conventional color histogram using the color information of input image.

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A Study on the Improvement of Skin Loss Area in Skin Color Extraction for Face Detection (얼굴 검출을 위한 피부색 추출 과정에서 피부색 손실 영역 개선에 관한 연구)

  • Kim, Dong In;Lee, Gang Seong;Han, Kun Hee;Lee, Sang Hun
    • Journal of the Korea Convergence Society
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    • v.10 no.5
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    • pp.1-8
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    • 2019
  • In this paper, we propose an improved facial skin color extraction method to solve the problem that facial surface is lost due to shadow or illumination in skin color extraction process and skin color extraction is not possible. In the conventional HSV method, when facial surface is brightly illuminated by light, the skin color component is lost in the skin color extraction process, so that a loss area appears on the face surface. In order to solve these problems, we extract the skin color, determine the elements in the H channel value range of the skin color in the HSV color space among the lost skin elements, and combine the coordinates of the lost part with the coordinates of the original image, To minimize the number of In the face detection process, the face was detected using the LBP Cascade Classifier, which represents texture feature information in the extracted skin color image. Experimental results show that the proposed method improves the detection rate and accuracy by 5.8% and 9.6%, respectively, compared with conventional RGB and HSV skin color extraction and face detection using the LBP cascade classifier method.

Design and Implementation of the Stop line and Crosswalk Recognition Algorithm for Autonomous UGV (자율 주행 UGV를 위한 정지선과 횡단보도 인식 알고리즘 설계 및 구현)

  • Lee, Jae Hwan;Yoon, Heebyung
    • Journal of the Korean Institute of Intelligent Systems
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    • v.24 no.3
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    • pp.271-278
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    • 2014
  • In spite of that stop line and crosswalk should be aware of the most basic objects in transportation system, its features extracted are very limited. In addition to image-based recognition technology, laser and RF, GPS/INS recognition technology, it is difficult to recognize. For this reason, the limited research in this area has been done. In this paper, the algorithm to recognize the stop line and crosswalk is designed and implemented using image-based recognition technology with the images input through a vision sensor. This algorithm consists of three functions.; One is to select the area, in advance, needed for feature extraction in order to speed up the data processing, 'Region of Interest', another is to process the images only that white color is detected more than a certain proportion in order to remove the unnecessary operation, 'Color Pattern Inspection', the other is 'Feature Extraction and Recognition', which is to extract the edge features and compare this to the previously-modeled one to identify the stop line and crosswalk. For this, especially by using case based feature comparison algorithm, it can identify either both stop line and crosswalk exist or just one exists. Also the proposed algorithm is to develop existing researches by comparing and analysing effect of in-vehicle camera installation and changes in recognition rate of distance estimation and various constraints such as backlight and shadow.

Region-based Building Extraction of High Resolution Satellite Images Using Color Invariant Features (색상 불변 특징을 이용한 고해상도 위성영상의 영역기반 건물 추출)

  • Ko, A-Reum;Byun, Young-Gi;Park, Woo-Jin;Kim, Yong-Il
    • Korean Journal of Remote Sensing
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    • v.27 no.2
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    • pp.75-87
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    • 2011
  • This paper presents a method for region-based building extraction from high resolution satellite images(HRSI) using integrated information of spectral and color invariant features without user intervention such as selecting training data sets. The purpose of this study is also to evaluate the effectiveness of the proposed method by applying to IKONOS and QuickBird images. Firstly, the image is segmented by the MSRG method. The vegetation and shadow regions are automatically detected and masked to facilitate the building extraction. Secondly, the region merging is performed for the masked image, which the integrated information of the spectral and color invariant features is used. Finally, the building regions are extracted using the shape feature for the merged regions. The boundaries of the extracted buildings are simplified using the generalization techniques to improve the completeness of the building extraction. The experimental results showed more than 80% accuracy for two study areas and the visually satisfactory results obtained. In conclusion, the proposed method has shown great potential for the building extraction from HRSI.

Gait Recognition Using Multiple Feature detection (다중 특징점 검출을 이용한 보행인식)

  • Cho, Woon;Kim, Dong-Hyeon;Paik, Joon-Ki
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.44 no.6
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    • pp.84-92
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    • 2007
  • The gait recognition is presented for human identification from a sequence of noisy silhouettes segmented from video by capturing at a distance. The proposed gait recognition algorithm gives better performance than the baseline algorithm because of segmentation of the object by using multiple modules; i) motion detection, ii) object region detection, iii) head detection, and iv) active shape models, which solve the baseline algorithm#s problems to make background, to remove shadow, and to be better recognition rates. For the experiment, we used the HumanID Gait Challenge data set, which is the largest gait benchmarking data set with 122 objects, For realistic simulation we use various values for the following parameters; i) viewpoint, ii) shoe, iii) surface, iv) carrying condition, and v) time.

A Study on Recognition of Moving Object Crowdedness Based on Ensemble Classifiers in a Sequence (혼합분류기 기반 영상내 움직이는 객체의 혼잡도 인식에 관한 연구)

  • An, Tae-Ki;Ahn, Seong-Je;Park, Kwang-Young;Park, Goo-Man
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.2A
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    • pp.95-104
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    • 2012
  • Pattern recognition using ensemble classifiers is composed of strong classifier which consists of many weak classifiers. In this paper, we used feature extraction to organize strong classifier using static camera sequence. The strong classifier is made of weak classifiers which considers environmental factors. So the strong classifier overcomes environmental effect. Proposed method uses binary foreground image by frame difference method and the boosting is used to train crowdedness model and recognize crowdedness using features. Combination of weak classifiers makes strong ensemble classifier. The classifier could make use of potential features from the environment such as shadow and reflection. We tested the proposed system with road sequence and subway platform sequence which are included in "AVSS 2007" sequence. The result shows good accuracy and efficiency on complex environment.

Extraction of Pyrophyllite Mineralized Zone using Characteristics of Spectral Reflectance of Rock Samples (암석분광반사율 특성을 이용한 납석 광화대 추출)

  • Chi, Kwang-Hoon;Lee, Hong-Jin
    • Korean Journal of Remote Sensing
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    • v.23 no.6
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    • pp.493-500
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    • 2007
  • In general, it accomplished a spectral reflectance analysis to be, the measurement results appear differently by targets, methods and condition. This paper presents a standard methodology for preprocessing mineral/rock samples and setting the distance from a target to the sensor, and then examines closely the spectral features for pyrophyllite. The size of mineral/rock samples is various according to the condition and scale of outcrop, so it is important to maintain the distance between the sensor and the sample. Before standardization for preprocessing samples and the sensor and sample distance, we prepare various rock samples (Quartz Porphyry) such as natural rock, pebble, powder and cutting rock. For a qualitative analysis to minimize the effect of surface condition of the sample and shadow, we maintains the distance from the sample to the sensor at 30cm and measures three times repeatedly for cutting the sample at $1{\sim}2cm$ thickness. To illustrate the proposed methodology, a case study for pyrophyllite was carried out. In this study, pyrophyllite showed an absorption pattern at wave length of 1.406nm, 1,868nm, 2.180nm and 2.309nm, and a higher grade represented strong absorption at 1.406nm and 2.180 nm. These absorption feature corresponds the band 7 of LANDSAT TM and band 8 of ASTER imageries. So, using these results, pyrophyllite deposits were extracted from other features (such as barren area, concrete area, bed of river, stone pit area etc.).