• Title/Summary/Keyword: distortion quantitative measurement

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Objective Image Quality Metric for Block-Based DCT Image Coder Using Structural Distortion Measurement (구조적 왜곡특성 측정을 이용한 블록기반 DCT 영상 부호화기의 객관적 화질평가)

  • Chung Tae-Yun
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.52 no.7
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    • pp.434-441
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    • 2003
  • This paper proposes a new quantitative and objective image quality metric which is essential to verify the performance of block-based DCT image coding. The proposed metric considers not only global distortion of coded image such as spatial frequency sensitivity and channel masking using HVS based multi-channel model, but also structural distortions caused block-based coding. The experimental results show a strong correlation between proposed metric and subjective metric.

Objective Image Quality Metric for Block-Based DCT Image Coder-using Structural Distortion Measurement (구조적 왜곡특성 측정을 이용한 블록기반 DCT 영상 부호화기의 객관적 화질평가)

  • Jeong, Tae Yun
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.7
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    • pp.434-434
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    • 2003
  • This paper proposes a new quantitative and objective image quality metric which is essential to verify the performance of block-based DCT image coding The proposed metric considers not only global distortion of coded image such as spatial frequency sensitivity and channel masking using HVS based multi-channel model, but also structural distortions caused block-based coding. The experimental results show a strong correlation between propose(B metric and subjective metric.

Distortion Correction of Surface Temperature Measurement Using an Infrared Camera (적외선 카메라를 이용한 표면온도측정의 왜곡 보정)

  • Lee, Sungmin;Kim, Ikhyun;Lee, Jong Kook;Byun, Yunghwan;Park, Gisu
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.7
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    • pp.545-551
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    • 2016
  • Surface temperature of supersonic wind tunnel model was measured using an infrared thermography technique. To measure the temperature quantitatively, various calibration techniques such as blackbody calibration which converts detected camera signal to temperature, distortion correction due to the camera lens and an imbalance of camera pose, and emissivity calibration which considers viewing angles to the model surface, were employed. Throughout the study, for the quantitative as well as qualitative surface temperature measurement, it was verified that the distortion correction must be considered even for the use of two-dimensional model in aerodynamics testing.

Variance Analysis for State Estimation In Communication Channel with Finite Bandwidth (유한한 대역폭을 가지는 통신 채널에서의 상태 추정값에 대한 분산 해석)

  • Fang, Tae-Hyun;Choi, Jae-Weon
    • Proceedings of the KSME Conference
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    • 2000.11a
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    • pp.693-698
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    • 2000
  • Aspects of classical information theory, such as rate distortion theory, investigate how to encode and decode information from an independently identically distributed source so that the asymptotic distortion rate between the source and its quantized representation is minimized. However, in most natural dynamics, the source state is highly corrupted by disturbances, and the measurement contains the noise. In recent coder-estimator sequence is developed for state estimation problem based on observations transmitted with finite communication capacity constraints. Unlike classical estimation problems where the observation is a continuous process corrupted by additive noises, the condition is that the observations must be coded and transmitted over a digital communication channel with finite capacity. However, coder-estimator sequence does not provide such a quantitative analysis as a variance for estimation error. In this paper, under the assumption that the estimation error is Gaussian distribution, a variance for coder-estimation sequence is proposed and its fitness is evaluated through simulations with a simple example.

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USE OF NEAR INFRARED FOR THE QUANTITATIVE ANALYSES OF BAUXITE

  • Walker, Graham S.;Cirulis, Robyn;Fletcher, Benjimin;Chandrashekar, S.
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1171-1171
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    • 2001
  • Quantitative analysis is an important requirement in exploration, mining and processing of minerals. There is an increasing need for the use of quantitative mineralogical data to assist with bore hole logging, deposit delineation, grade control, feed to processing plants and monitoring of solid process residues. Quantitative analysis using X-Ray Powder Diffraction (XRD) requires fine grinding and the addition of a reference material, or the application of Rietveld analysis to XRD patterns to provide accurate analysis of the suite of minerals present. Whilst accurate quantitative data can be obtained in this manner, the method is time consuming and limited to the laboratory. Mid infrared when combined with multivariant analysis has also been used for quantitative analysis. However, factors such as the absorption coefficients and refractive index of the minerals requires special sample preparation and dilution in a dispersive medium, such as KBr to minimize distortion of spectral features. In contrast, the lower intensity of the overtones and combinations of the fundamental vibrations in the near infrared allow direct measurement of virtually any solid without special sample preparation or dilution. Thus Near Infrared Spectroscopy (NIR) has found application for quantitative on-line/in line analysis and control in a range of processing applications which include, moisture control in clay and textile processing, fermentation processes, wheat analysis, gasoline analysis and chemicals and polymers. It is developing rapidly in the mineral exploration industry and has been underpinned by the development of portable NIR spectrometers and spectral libraries of a wide range of minerals. For example, iron ores have been identified and characterized in terms of the individual mineral components using field spectrometers. Data acquisition time of NIR field instruments is of the order of seconds and sample preparation is minimal. Consequently these types of spectrometers have great potential for in-line or on-line application in the minerals industry. To demonstrate the applicability of NIR field spectroscopy for quantitative analysis of minerals, a specific example on the quantification of lateritic bauxites will be presented. It has been shown that the application of Partial Least Squares regression analysis (PLS) to the NIR spectra can be used to quantify chemistry and mineralogy in a range of lateritic bauxites. Important, issues such as sampling, precision, repeatability, and replication which influence the results will be discussed.

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Moving Object Preserving Seamline Estimation (이동 객체를 보존하는 시접선 추정 기술)

  • Gwak, Moonsung;Lee, Chanhyuk;Lee, HeeKyung;Cheong, Won-Sik;Yang, Seungjoon
    • Journal of Broadcast Engineering
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    • v.24 no.6
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    • pp.992-1001
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    • 2019
  • In many applications, images acquired from multiple cameras are stitched to form an image with a wide viewing angle. We propose a method of estimating a seam line using motion information to stitch multiple images without distortion of the moving object. Existing seam estimation techniques usually utilize an energy function based on image gradient information and parallax. In this paper, we propose a seam estimation technique that prevents distortion of moving object by adding temporal motion information, which is calculated from the gradient information of each frame. We also propose a measure to quantify the distortion level of stitched images and to verify the performance differences between the existing and proposed methods.

A Study on Edge Alignment of AUT using Image Processing (영상처리를 이용한 AUT 끝단 정렬에 관한 연구)

  • Kim, yang-woo;Yu, tae-keun;Kwak, nae-joung
    • Proceedings of the Korea Contents Association Conference
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    • 2007.11a
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    • pp.97-100
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    • 2007
  • Recently, there is developed various antenna's models due to increment of wireless communication the need of quantitative study on antenna's measuring technology gets to highlight. In this paper, we propose algorithm of antenna's edge alignment for making automatic measuring system of antenna's characteristics of near-field measurement system of antenna. The proposed algorithm gets the bottom image of antenna from camera, extracts antenna object, and finds the boundary the object. The proposed algorithm calculates distortion of the object using the extracted boundary and the angle to correct this. The proposed algorithm is applied to the standard gain horn antenna. The results show that antenna's object is efficiently extracted and the angle for correcting the error is calculated.

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3D Accuracy Analysis of Mobile Phone-based Stereo Images (모바일폰 기반 스테레오 영상에서 산출된 3차원 정보의 정확도 분석)

  • Ahn, Heeran;Kim, Jae-In;Kim, Taejung
    • Journal of Broadcast Engineering
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    • v.19 no.5
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    • pp.677-686
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    • 2014
  • This paper analyzes the 3D accuracy of stereo images captured from a mobile phone. For 3D accuracy evaluation, we have compared the accuracy result according to the amount of the convergence angle. In order to calculate the 3D model space coordinate of control points, we perform inner orientation, distortion correction and image geometry estimation. And the quantitative 3D accuracy was evaluated by transforming the 3D model space coordinate into the 3D object space coordinate. The result showed that relatively precise 3D information is generated in more than $17^{\circ}$ convergence angle. Consequently, it is necessary to set up stereo model structure consisting adequate convergence angle as an measurement distance and a baseline distance for accurate 3D information generation. It is expected that the result would be used to stereoscopic 3D contents and 3D reconstruction from images captured by a mobile phone camera.