• Title/Summary/Keyword: conversion algorithm

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An Improved RANSAC Algorithm Based on Correspondence Point Information for Calculating Correct Conversion of Image Stitching (이미지 Stitching의 정확한 변환관계 계산을 위한 대응점 관계정보 기반의 개선된 RANSAC 알고리즘)

  • Lee, Hyunchul;Kim, Kangseok
    • KIPS Transactions on Software and Data Engineering
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    • v.7 no.1
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    • pp.9-18
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    • 2018
  • Recently, the use of image stitching technology has been increasing as the number of contents based on virtual reality increases. Image Stitching is a method for matching multiple images to produce a high resolution image and a wide field of view image. The image stitching is used in various fields beyond the limitation of images generated from one camera. Image Stitching detects feature points and corresponding points to match multiple images, and calculates the homography among images using the RANSAC algorithm. Generally, corresponding points are needed for calculating conversion relation. However, the corresponding points include various types of noise that can be caused by false assumptions or errors about the conversion relationship. This noise is an obstacle to accurately predict the conversion relation. Therefore, RANSAC algorithm is used to construct an accurate conversion relationship from the outliers that interfere with the prediction of the model parameters because matching methods can usually occur incorrect correspondence points. In this paper, we propose an algorithm that extracts more accurate inliers and computes accurate transformation relations by using correspondence point relation information used in RANSAC algorithm. The correspondence point relation information uses distance ratio between corresponding points used in image matching. This paper aims to reduce the processing time while maintaining the same performance as RANSAC.

A Study on the Voice Conversion Algorithm with High Quality (고음질을 갖는 음색변경에 관한 연구)

  • 박형빈;배명진
    • Proceedings of the IEEK Conference
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    • 2000.09a
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    • pp.157-160
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    • 2000
  • In the generally a voice conversion has used VQ(Vector Quantization) for partitioning the spectral feature and has performed by adding an appropriate offset vector to the source speaker's spectral vector. But there is not represented the target speaker's various characteristics because of discrete characteristics of transformed parameter. In this paper, these problems are solved by using the LMR(Linear Multivariate Regression) instead of the mapping codebook which is determined to the relationship of source and target speaker vocal tract characteristics. Also we propose the method for solved the discontinuity which is caused by applying to time aligned parameters using Dynamic Time Warping the time or pitch-scale modified speech. In our proposed algorithm for overcoming the transitional discontinuities, first of all, we don't change time or pitch scale and by using the LMR change a speaker's vocal tract characteristics in speech with non-modified time or pitch. Compared to existed methods based on VQ and LMR, we have much better voice quality in the result of the proposed algorithm.

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Conversion Algorithm for measuring Scattering Parameters of Multiport System with a 2-port Network Analyzer (2포트 회로망 분석기를 이용한 다중포트 시스템의 S파라미터 측정에 관한 컨버전 알고리즘)

  • Long, Luong Duc;Lee, June-Sang;Bae, Hyeon-Ju;Lee, Jae-Joong;Nah, Wan-Soo
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1654-1655
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    • 2011
  • This paper presents an algorithm applied to measure scattering parameters of a Multiport device with a 2-port Vector Network Analyzer (VNA). By employing the conversion of Scattering matrix with different reference impedances at ports, data obtained from 2-port configuration measurements can be synthesized to build the full scattering matrix of this device. A good agreement of estimated and measured parameters verified the performance of the algorithm.

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STEADY-STATE OPTIMIZATION OF AN INTERNAL COMBUSTION ENGINE FOR HYBRID ELECTRIC VEHICLES

  • Wang, F.;Zhang, T.;Yang, L.;Zhuo, B.
    • International Journal of Automotive Technology
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    • v.8 no.3
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    • pp.361-373
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    • 2007
  • In previous work, an approach based on maximizing the efficiency of an internal combustion engine while ignoring the power conversion efficiency of other powertrain components, such as the electric motor and power battery or ultracapacitor, was implemented in the steady-state optimization of an internal combustion engine for hybrid electric vehicles. In this paper, a novel control algorithm was developed and successfully justified as the basis for maximal power conversion efficiency of overall powertrain components. Results indicated that fuel economy improvement by 3.9% compared with the conventional control algorithm under China urban transient-state driving-cycle conditions. In addition, using the view of the novel control algorithm, maximal power generation of the electric motor can be chosen.

Estimation of Theoretical Yield for Ethanol Production from D-Xylose by Recombinant Saccharomyces cerevisiae Using Metabolic Pathway Synthesis Algorithm

  • Lee, Tae-Hee;Kim, Min-Young;Ryu, Yeon-Woo;Seo, Jin-Ho
    • Journal of Microbiology and Biotechnology
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    • v.11 no.3
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    • pp.384-388
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    • 2001
  • The metabolic pathway synthesis algorithm was applied to estimate the maximum ethanol yield from xylose in a model recombinant Saccharomyces cerevisiae strain containing the genes involved in xylose metabolism. The stoichiometrically independent pathways were identified by constructing a biochemical reaction network for conversion of xylose to ethanol in the recombinant S. cerevisiae. Two independent pathways were obtained in xylose-assimilating recombinant S. cerevisiae as opposed to six independent pathways for conversion of glucose to ethanol. The maximum ethanol yield from xylose was estimated to be 0.46 g/g, which was lower than the known value of 0.51 g/g for glucose-fermenting and wild-type xylose-fermenting yeasts.

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A Look-Up Table Based Error Diffusion Algorithm for Dynamic False Contour Reduction of Plasma Display Panels

  • Lee, Ho-Seop;Kim, Choon-Woo
    • Journal of Information Display
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    • v.2 no.2
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    • pp.32-38
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    • 2001
  • PDP(plasma display panel) represents the gray levels by the pulse number modulation technique that results in undesirable dynamic false contours on moving images. This paper proposes a LUT(Look-up table) based error diffusion algorithm for reduction of the dynamic false contours. A quantitative measure of the dynamic false contours is defined first. The measure of the dynamic false contours is calculated through simulation of every gray level combination of two consecutive frames. Based on the calculated measures, a modified gray level for a pair of gray levels of two consecutive frames is chosen to reduce the dynamic false contours. The chosen gray levels serve as contents of a gray level conversion LUT. Given a pair of gray levels of two consecutive frames, the gray level of current frame is modified based on the gray level conversion LUT. The new gray level is displayed on PDP. An error diffusion algorithm is, then, applied to compensate for the differences in the gray levels.

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A Joint Scheme of AGC and Gain/Phase Mismatch Compensation for QPSK DCR

  • Song, Yun-Jeong;Lee, Ho-Jin;Ra, Sung-Woong;Kim, Young-Wan
    • ETRI Journal
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    • v.26 no.5
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    • pp.501-504
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    • 2004
  • This paper presents a simple gain/phase blind compensation algorithm with an automatic gain control (AGC) function for the adoption of the AGC function and compensation for gain/phase imbalances in quadrature phase shift keying (QPSK) direct conversion receivers (DCRs). The AGC function is interactively operated with the compensation algorithm for gain/phase imbalances. By detecting the gain sum and difference values between the I-channel and Q-channel, the combined AGC and gain imbalance compensation algorithm provides a simpler DCR architecture.

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Infrared Visual Inertial Odometry via Gaussian Mixture Model Approximation of Thermal Image Histogram (열화상 이미지 히스토그램의 가우시안 혼합 모델 근사를 통한 열화상-관성 센서 오도메트리)

  • Jaeho Shin;Myung-Hwan Jeon;Ayoung Kim
    • The Journal of Korea Robotics Society
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    • v.18 no.3
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    • pp.260-270
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    • 2023
  • We introduce a novel Visual Inertial Odometry (VIO) algorithm designed to improve the performance of thermal-inertial odometry. Thermal infrared image, though advantageous for feature extraction in low-light conditions, typically suffers from a high noise level and significant information loss during the 8-bit conversion. Our algorithm overcomes these limitations by approximating a 14-bit raw pixel histogram into a Gaussian mixture model. The conversion method effectively emphasizes image regions where texture for visual tracking is abundant while reduces unnecessary background information. We incorporate the robust learning-based feature extraction and matching methods, SuperPoint and SuperGlue, and zero velocity detection module to further reduce the uncertainty of visual odometry. Tested across various datasets, the proposed algorithm shows improved performance compared to other state-of-the-art VIO algorithms, paving the way for robust thermal-inertial odometry.

Motion Estimation Algorithm Using Variance and Adaptive Search Range for Frame Rate Up-Conversion (프레임 율 향상을 위한 분산 및 적응적 탐색영역을 이용한 움직임 추정 알고리듬)

  • Yu, Songhyun;Jeong, Jechang
    • Journal of Broadcast Engineering
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    • v.23 no.1
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    • pp.138-145
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    • 2018
  • In this paper, we propose a new motion estimation algorithm for frame rate up-conversion. The proposed algorithm uses the variance of errors in addition to SAD in motion estimation to find more accurate motion vectors. Then, it decides which motion vectors are wrong using the variance of neighbor motion vectors and the variance between current motion vector and neighbor's average motion vector. Next, incorrect motion vectors are corrected by weighted sum of eight neighbor motion vectors. Additionally, we propose adaptive search range algorithm, so we can find more accurate motion vectors and reduce computational complexity at the same time. As a result, proposed algorithm improves the average peak signal-to-noise ratio and structural similarity up to 1.44 dB and 0.129, respectively, compared with previous algorithms.

Effective Frame Rate Up-Conversion Method Using Adaptive Motion Refinement Based on ROI Separation (관심영역 분리에 따른 적응적인 움직임 보정에 기초한 효과적인 프레임 율 증가 기법)

  • Lee, Beom-yong;Kim, Jin-soo
    • The Journal of the Korea Contents Association
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    • v.16 no.2
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    • pp.310-319
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    • 2016
  • This paper proposes an effective FRUC (Frame Rate Up-Conversion) technique, which is based on ROI (Region Of Interest) separations and adaptive motion vector refinement. In this paper, in order to overcome the weakness of the EBME (Extended Bi-lateral Motion Estimation) algorithm, which is widely known in FRUC techniques, first, the proposed algorithm performs a bi-directional motion estimation for the complementary asymmetric region. Then, the proposed algorithm classifies each block into ROI or non-ROI block and refine motion vectors in accordance with their block characteristics to have a higher accuracy than the conventional EBME algorithm, specially, for the occlusion regions. The experimental results show that the proposed algorithm can improves 0.59dB on average PSNR as compared to the conventional method.