• Title/Summary/Keyword: image assessment

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Evaluation of Various Tone Mapping Operators for Backward Compatible JPEG Image Coding

  • Choi, Seungcheol;Kwon, Oh-Jin;Jang, Dukhyun;Choi, Seokrim
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.9
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    • pp.3672-3684
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    • 2015
  • Recently, the standardization of backward compatible JPEG image coding for high dynamic range (HDR) image has been undertaken to establish an international standard called "JPEG XT." The JPEG XT consists of two layers: the base layer and the residual layer. The base layer contains tone mapped low dynamic range (LDR) image data and the residual layer contains the error signal used to reconstruct the HDR image. This paper gives the result of a study to evaluate the overall performance of tone mapping operators (TMOs) for this standard. The evaluation is performed using five HDR image datasets and six TMOs for profiles A, B, and C of the proposed JPEG XT standard. The Tone Mapped image Quality Index (TMQI) and no reference image quality assessment (NR IQA) are used for measuring the LDR image quality. The peak signal to noise ratio (PSNR) is used to evaluate the overall compression performance of JPEG XT profiles A, B, and C. In TMQI and NR IQA measurements, TMOs using display adaptive tone mapping and adaptive logarithmic mapping each gave good results. A TMO using adaptive logarithmic mapping gave good PSNRs.

Object Edge-based Image Generation Technique for Constructing Large-scale Image Datasets (대형 이미지 데이터셋 구축을 위한 객체 엣지 기반 이미지 생성 기법)

  • Ju-Hyeok Lee;Mi-Hui Kim
    • Journal of IKEEE
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    • v.27 no.3
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    • pp.280-287
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    • 2023
  • Deep learning advancements can solve computer vision problems, but large-scale datasets are necessary for high accuracy. In this paper, we propose an image generation technique using object bounding boxes and image edge components. The object bounding boxes are extracted from the images through object detection, and image edge components are used as input values for the image generation model to create new image data. As results of experiments, the images generated by the proposed method demonstrated similar image quality to the source images in the image quality assessment, and also exhibited good performance during the deep learning training process.

Self-assessment, Self-efficacy and Satisfaction after OSCE using Smart Phone (스마트 폰을 활용한 객관적 임상시험 후 자기평가와 자기효능감 및 만족도)

  • Park, Ju-Young
    • The Journal of Korean Academic Society of Nursing Education
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    • v.18 no.1
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    • pp.120-130
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    • 2012
  • Background: The purpose of this study was to examine relationships among self-assessment, self-efficacy, and satisfaction after OSCE(Objective Structured Clinical Examination) using smart phone. Methods: The convenience sample was consisted of 90 nursing college students. The data were collected from November 15 to November 18 in 2011. The data were analyzed using SPSS win 19.0 program. Data were analyzed with descriptive statistics including t-test, ANOVA and Pearson's correlation coefficient to compare self-efficacy and satisfaction by subject's general related characteristics and to examine the relationships among variables. Results: The level of self-efficacy was 3.48(${\pm}0.27$). The level of satisfaction was 4.01(${\pm}0.54$). Self-efficacy was significant relationship satisfaction with practice education (r=.380, p=.045), satisfaction with the method of practical tests (r=.270, p=.009), and satisfaction with major (r=.250, p=.015). There was significant relationship between satisfaction with major and satisfaction with practice education (r=.240, p=.020). Conclusion: Comprehensive intervention promoting self-efficacy, interpersonal relationship, and perceived image of nurses after practicum is needed to improve self-efficacy and satisfaction, for those who can not better interpersonal relationships, perceived image of nurses after practicum.

A review of rotorcraft Unmanned Aerial Vehicle (UAV) developments and applications in civil engineering

  • Liu, Peter;Chen, Albert Y.;Huang, Yin-Nan;Han, Jen-Yu;Lai, Jihn-Sung;Kang, Shih-Chung;Wu, Tzong-Hann;Wen, Ming-Chang;Tsai, Meng-Han
    • Smart Structures and Systems
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    • v.13 no.6
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    • pp.1065-1094
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    • 2014
  • Civil engineers always face the challenge of uncertainty in planning, building, and maintaining infrastructure. These works rely heavily on a variety of surveying and monitoring techniques. Unmanned aerial vehicles (UAVs) are an effective approach to obtain information from an additional view, and potentially bring significant benefits to civil engineering. This paper gives an overview of the state of UAV developments and their possible applications in civil engineering. The paper begins with an introduction to UAV hardware, software, and control methodologies. It also reviews the latest developments in technologies related to UAVs, such as control theories, navigation methods, and image processing. Finally, the paper concludes with a summary of the potential applications of UAV to seismic risk assessment, transportation, disaster response, construction management, surveying and mapping, and flood monitoring and assessment.

Illumination Compensation Based on Conformity Assessment of Highlight Regions (고휘도 영역의 적합성 평가에 기반한 광원 보상)

  • Kwon, Oh-Seol
    • Journal of Broadcast Engineering
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    • v.19 no.1
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    • pp.75-82
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    • 2014
  • This paper proposes an illuminant compensation method using a camera noise analysis without segmentation in the dichromatic reflectance model. In general, pixels within highlight regions include large amounts of information on the image illuminant. Thus, the analysis of highlight regions provides a relatively easy means of determining the characteristics of an image illuminant. Currently, conventional methods require regional segmentation and the accuracy of this segmentation then affects the illuminant estimation. Therefore, the proposed method estimates the illuminant without segmentation based on a conformity assessment of highlight regions. Furthermore, error factors, such as noise and sensor non-uniformity, can be reduced by the conformity assessment.

The Satellite Observation for Spatial Changes of Vegetation in Saemangum Tidal Flat (새만금 갯벌의 식생 공간변화에 대한 위성관측)

  • Jeong, Jong-Chul
    • Journal of Environmental Impact Assessment
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    • v.23 no.2
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    • pp.150-156
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    • 2014
  • The aim of this study is to detection of changed vegetation area of Saemangeum tidal flat with comparison of topography and surface sediments during the dyke construction. Sedimentary facies of four seasons of 2001 from inside Saemangeum tidal flat revealed homogeneous layers in the upper part, however near sea side tidal flat were detecting with carried out rapid sediment deposition during the dyke construction using satellite image spatial analysis. The sedimentation types inside Saemangeum tidal flat were classified with vegetation types, which were well matched with the sedimentation pattern revealed by change in vegetation patterns.

A Study of Application of Remotely Sensed Data for the Management of National Parks - in case of Bukhansan National Park- (국립공원관리를 위한 위성영상 활용방안에 관한 연구 -북한산 국립공원을 사례로-)

  • Park, Kyeong;Chang, Eun-Mi;Scene, Sang-Hee
    • Journal of Environmental Impact Assessment
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    • v.10 no.3
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    • pp.167-174
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    • 2001
  • National Parks in Korea occupy about four percents of South Korean land. This paper aims to prove the potentiality of the application of remotely sensed data for the effective management of National Parks. Different satellite images such as Landsat TM, IRS-1C, Alternative image, and IKONOS image are analyzed for the detection of changes, the extraction of degraded areas, and the comparison of Normalized Difference Vegetation Index (NDVI) in Bukhansan National Park. The artificial structures such as buildings and paved areas are overvalued in relatively higher resolution data. The result showed that the choice of images should be determined according to specific purposes and the combination of different resolution data may be the solution for the effective management of National Park.

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Morphologic Assessment of Corpus Callosum in the Patient of Alzheimer Disease using Magnetic Resonance Imaging

  • Seoung, Youl-Hun;Choe, Bo-Young
    • Journal of the Korean Magnetic Resonance Society
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    • v.13 no.2
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    • pp.84-95
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    • 2009
  • The purpose of this study was to evaluate the usefulness of the measurement of corpus callosum (CC) size in the Alzheimer patient by using magnetic resonance (MR) midsagittal image. We performed MR scanning in 20 normal high age group, and in 20 mild cognitive impairment (MCI) group, and in 20 Alzheimer disease (AD) group. The following parameters were employed in AD group: TRITE/FA 6650ms/66ms/$90^{\circ}$, NEX 2, Thickness/Gap 2/0, FOV 220mm. The magnetic field strength was used at 3.0 Tesla. We selected midsagittal image of the brain by using view forum program, measured CC size, which were anteroposterior length, diameter of genu, body, narrowing portion, and splenium. The present study demonstrates that CC size of Alzheimer disease can be useful for clinical assessment concerning the diameter of genu, body, and splenium.

Digital Video Quality Assessment using the Statistics of Boundary Strength of H.264/AVC (H.264/AVC의 경계 세기 통계를 이용한 디지털 비디오에서의 객관적 화질 측정)

  • Jung, Kwang-Su;Lee, Seon-Oh;Sim, Dong-Gyu
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.45 no.3
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    • pp.64-73
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    • 2008
  • In this paper, we propose a novel objective video quality assessment method from encoded H.264/AVC.. Conventional algorithms have been proposed to assess video/image quality with image frames reconstructed in a decoder side. On the other hand, the proposed assessment is conducted with the syntax elements which are embedded in a bitstream. The proposed BS-based algorithm makes use of the statistics of boundary strength(BS) which are employed in the H.264/AVC. The proposed algorithm has lower computational complexity than conventional methods, EPSNR and Blockiness, resulting that it can accomplish assessment of the video quality in real time. Furthermore, the accuracy of the proposed video quality assessment is about 32% and 65% better than several conventional algorithms.

The Assessment on the Characteristics of Quantitative Image in Digora$\textregistered$ (Digora$\textregistered$에서 정량영상의 특성에 대한 평가)

  • Kim Jae-Duk
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.29 no.2
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    • pp.397-405
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    • 1999
  • Purpose: To clarify the usefulness and the limitation of Digora system/sup (R)/ by evaluating the physical characteristics as the quantitative image on Image Plate(Ip). Materials and Methods: Radiograms were taken by Heliodent MD(Siemens Co.. Germany) with the image plate for adult. Cu-step wedge as reference material. and three pieces of dry mandibular bone. Image analysis was performed by single color enhancement. density measurement with histogram. The relationship between the exposure conditions and the distribution of the pixel values of the image. the variation of pixel values of each step of Cu-step wedge at two different area and Cu-equivalent value of three pieces of dry mandibular bone measure by the conversion equation. Results: There was no linear relationship between the exposure condition and the average pixel value of the image. of which the distribution was not even. The pixel value differences between the center portion and the periphery were ranged from 60 to 70 in vertical plane and from 15 to 26 in horizontal plane. Two plot profile formed at two different areas of the Cu-step wedge were different. The measured Cu-equivalent values showed the discrepancy among the times of measurement. Conclusion: As above results. Image Plate(Ip) of Digora system/sup (R)/ showed the limitation as the quantitative image. The physical property of IP was expected to need to be compensated for the quantitative evaluation of the bone or others

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