• Title/Summary/Keyword: image pre-processing

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A Study on Detection and Recognition of Facial Area Using Linear Discriminant Analysis

  • Kim, Seung-Jae
    • International journal of advanced smart convergence
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    • v.7 no.4
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    • pp.40-49
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    • 2018
  • We propose a more stable robust recognition algorithm which detects faces reliably even in cases where there are changes in lighting and angle of view, as well it satisfies efficiency in calculation and detection performance. We propose detects the face area alone after normalization through pre-processing and obtains a feature vector using (PCA). The feature vector is applied to LDA and using Euclidean distance of intra-class variance and inter class variance in the 2nd dimension, the final analysis and matching is performed. Experimental results show that the proposed method has a wider distribution when the input image is rotated $45^{\circ}$ left / right. We can improve the recognition rate by applying this feature value to a single algorithm and complex algorithm, and it is possible to recognize in real time because it does not require much calculation amount due to dimensional reduction.

Optimised ML-based System Model for Adult-Child Actions Recognition

  • Alhammami, Muhammad;Hammami, Samir Marwan;Ooi, Chee-Pun;Tan, Wooi-Haw
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.2
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    • pp.929-944
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    • 2019
  • Many critical applications require accurate real-time human action recognition. However, there are many hurdles associated with capturing and pre-processing image data, calculating features, and classification because they consume significant resources for both storage and computation. To circumvent these hurdles, this paper presents a recognition machine learning (ML) based system model which uses reduced data structure features by projecting real 3D skeleton modality on virtual 2D space. The MMU VAAC dataset is used to test the proposed ML model. The results show a high accuracy rate of 97.88% which is only slightly lower than the accuracy when using the original 3D modality-based features but with a 75% reduction ratio from using RGB modality. These results motivate implementing the proposed recognition model on an embedded system platform in the future.

Transfer learning for crack detection in concrete structures: Evaluation of four models

  • Ali Bagheri;Mohammadreza Mosalmanyazdi;Hasanali Mosalmanyazdi
    • Structural Engineering and Mechanics
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    • v.91 no.2
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    • pp.163-175
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    • 2024
  • The objective of this research is to improve public safety in civil engineering by recognizing fractures in concrete structures quickly and correctly. The study offers a new crack detection method based on advanced image processing and machine learning techniques, specifically transfer learning with convolutional neural networks (CNNs). Four pre-trained models (VGG16, AlexNet, ResNet18, and DenseNet161) were fine-tuned to detect fractures in concrete surfaces. These models constantly produced accuracy rates greater than 80%, showing their ability to automate fracture identification and potentially reduce structural failure costs. Furthermore, the study expands its scope beyond crack detection to identify concrete health, using a dataset with a wide range of surface defects and anomalies including cracks. Notably, using VGG16, which was chosen as the most effective network architecture from the first phase, the study achieves excellent accuracy in classifying concrete health, demonstrating the model's satisfactorily performance even in more complex scenarios.

Segmentation and Contents Classification of Document Images Using Local Entropy and Texture-based PCA Algorithm (지역적 엔트로피와 텍스처의 주성분 분석을 이용한 문서영상의 분할 및 구성요소 분류)

  • Kim, Bo-Ram;Oh, Jun-Taek;Kim, Wook-Hyun
    • The KIPS Transactions:PartB
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    • v.16B no.5
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    • pp.377-384
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    • 2009
  • A new algorithm in order to classify various contents in the image documents, such as text, figure, graph, table, etc. is proposed in this paper by classifying contents using texture-based PCA, and by segmenting document images using local entropy-based histogram. Local entropy and histogram made the binarization of image document not only robust to various transformation and noise, but also easy and less time-consuming. And texture-based PCA algorithm for each segmented region was taken notice of each content in the image documents having different texture information. Through this, it was not necessary to establish any pre-defined structural information, and advantages were found from the fact of fast and efficient classification. The result demonstrated that the proposed method had shown better performances of segmentation and classification for various images, and is also found superior to previous methods by its efficiency.

Application of Multi-Frame Based Super-Resolution Algorithm for a Color Recognition Enhancement for the UAV (복수영상기반 초해상도 색상인식능력향상 알고리즘의 무인기 적용)

  • Park, Jihoon;Kim, Jeongho;Lee, Daewoo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.45 no.3
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    • pp.180-190
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    • 2017
  • This paper describes the application of Multi-frame based super-resolution method to enhance resolution of image information from the UAV, and the improvement of UAV's ground target recognition ability. To verify this algorithm, we designed a flight/ground control system, and the UAV, and then the algorithm was validated using the UAV system with ground target. As a result of the comparison between the pre-applied image and post-applied one shows that the RMSE is from 0.0677 to 0.0315, NRMSE is from 7.4030% to 3.5726%, PSNR is from 23.3885dB to 30.0036dB, and SSIM is from 0.6996 to 0.8948. Through these results, we validate this study can enhance the resolution of UAV's image using Multi-frame based super-resolution algorithm.

Automatic Estimation of Geometric Translations Between High-resolution Optical and SAR Images (고해상도 광학영상과 SAR 영상 간 자동 변위량 추정)

  • Han, You Kyung;Byun, Young Gi;Kim, Yong Il
    • Journal of Korean Society for Geospatial Information Science
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    • v.20 no.3
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    • pp.41-48
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    • 2012
  • Using multi-sensor or multi-temporal high resolution satellite images together is essential for efficient applications in remote sensing area. The purpose of this paper is to estimate geometric difference of translations between high-resolution optical and SAR images automatically. The geometric and radiometric pre-processing steps were fulfilled to calculate the similarity between optical and SAR images by using Mutual Information method. The coarsest-level pyramid images of each sensor constructed by gaussian pyramid method were generated to estimate the initial translation difference of the x, y directions for calculation efficiency. The precise geometric difference of translations was able to be estimated by applying this method from coarsest-level pyramid image to original image in order. Yet even when considered only translation between optical and SAR images, the proposed method showed RMSE lower than 5m in all study sites.

Real Time Face Detection and Recognition using Rectangular Feature Based Classifier and PCA-based MLNN (사각형 특징 기반 분류기와 PCA기반 MLNN을 이용한 실시간 얼굴검출 및 인식)

  • Kim, Jong-Min;Lee, Kee-Jun
    • Journal of Digital Contents Society
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    • v.11 no.4
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    • pp.417-424
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    • 2010
  • In this paper the real-time face region was detected by suggesting the rectangular feature-based classifier and the robust detection algorithm that satisfied the efficiency of computation and detection performance was suggested. By using the detected face region as a recognition input image, in this paper the face recognition method combined with PCA and the multi-layer network which is one of the intelligent classification was suggested and its performance was evaluated. As a pre-processing algorithm of input face image, this method computes the eigenface through PCA and expresses the training images with it as a fundamental vector. Each image takes the set of weights for the fundamental vector as a feature vector and it reduces the dimension of image at the same time, and then the face recognition is performed by inputting the multi-layer neural network.

Impact Analysis of Deep Learning Super-resolution Technology for Improving the Accuracy of Ship Detection Based on Optical Satellite Imagery (광학 위성 영상 기반 선박탐지의 정확도 개선을 위한 딥러닝 초해상화 기술의 영향 분석)

  • Park, Seongwook;Kim, Yeongho;Kim, Minsik
    • Korean Journal of Remote Sensing
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    • v.38 no.5_1
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    • pp.559-570
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    • 2022
  • When a satellite image has low spatial resolution, it is difficult to detect small objects. In this research, we aim to check the effect of super resolution on object detection. Super resolution is a software method that increases the resolution of an image. Unpaired super resolution network is used to improve Sentinel-2's spatial resolution from 10 m to 3.2 m. Faster-RCNN, RetinaNet, FCOS, and S2ANet were used to detect vessels in the Sentinel-2 images. We experimented the change in vessel detection performance when super resolution is applied. As a result, the Average Precision (AP) improved by at least 12.3% and up to 33.3% in the ship detection models trained with the super-resolution image. False positive and false negative cases also decreased. This implies that super resolution can be an important pre-processing step in object detection, and it is expected to greatly contribute to improving the accuracy of other image-based deep learning technologies along with object detection.

Lunar Crater Detection using Deep-Learning (딥러닝을 이용한 달 크레이터 탐지)

  • Seo, Haingja;Kim, Dongyoung;Park, Sang-Min;Choi, Myungjin
    • Journal of Space Technology and Applications
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    • v.1 no.1
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    • pp.49-63
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    • 2021
  • The exploration of the solar system is carried out through various payloads, and accordingly, many research results are emerging. We tried to apply deep-learning as a method of studying the bodies of solar system. Unlike Earth observation satellite data, the data of solar system differ greatly from celestial bodies to probes and to payloads of each probe. Therefore, it may be difficult to apply it to various data with the deep-learning model, but we expect that it will be able to reduce human errors or compensate for missing parts. We have implemented a model that detects craters on the lunar surface. A model was created using the Lunar Reconnaissance Orbiter Camera (LROC) image and the provided shapefile as input values, and applied to the lunar surface image. Although the result was not satisfactory, it will be applied to the image of the permanently shadow regions of the Moon, which is finally acquired by ShadowCam through image pre-processing and model modification. In addition, by attempting to apply it to Ceres and Mercury, which have similar the lunar surface, it is intended to suggest that deep-learning is another method for the study of the solar system.

Standardization of Inspection and Imaging of Facial Color, and Design of Gloss-detecting Method (면색정보취득 制御條件 표준화 및 윤택측정방안 설계)

  • Chi, Gyoo Yong;Kim, Jong Won
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.29 no.4
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    • pp.289-294
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    • 2015
  • In order to make digital processing of facial color, standardization methods of photographing and observational requirements and gloss-detecting are done through preceding papers and actual experiences. Examiner's observational informations should be contained with original and temporary color, normalcy and deviation range and gloss. And these are interrelated with time, interior and exterior temperature, emotional state, so should be recorded too. Picturing procedure should be controlled in simple and practical but objective way. Just water cleansing, 15 to 20 minute resting, prohibiton of moisturizing of examinee are common for examiner. Temperature and moisture, width, light source requirement, brightness, polarizing filter of parlor and camera-to-object distance, posture of examinee are should be recorded. In addition, pre and post-revision of color and manifestation of color space after taking images are needed coping with construction of diagnostic database.