Kalman Filter Based Error Resilience for H.264 Motion Vector Recovery

Author(s):  
Ki-Hong Ko ◽  
Seong-Whan Kim
Author(s):  
Chih-Shan Liu ◽  
Jen-Chun Lin ◽  
Nai-Chung Yang ◽  
Chung-Ming Kuo
Keyword(s):  

2012 ◽  
Vol 29 (12) ◽  
pp. 1794-1810 ◽  
Author(s):  
Chanh Q. Kieu ◽  
Nguyen Minh Truong ◽  
Hoang Thi Mai ◽  
Thanh Ngo-Duc

Abstract In this study, sensitivities of the track and intensity forecasts of Typhoon Megi (2010) to the Cooperative Institute for Meteorological Satellite Studies (CIMSS) University of Wisconsin satellite atmospheric motion vector (AMV) dataset are examined. Assimilation of the CIMSS AMV dataset using the local ensemble transform Kalman filter implemented in the Weather Research and Forecasting model shows that the AMV data can significantly improve the track forecast of Typhoon Megi, especially the sharp turn from west-northwest to north after crossing the Philippines. By broadening the western Pacific subtropical high to the west, the AMV data can help reduce the eastward bias of the track, thus steering the storm away inimical shear environment and facilitating its subsequent development. Further sensitivity experiments with separated assimilation of the low- to midlevel (800–300 hPa) and upper-level (300–100 hPa) AMV winds reveal that, despite the sparse distribution of the low-level AMV winds with most of the data points located in the periphery of Megi’s main circulation, the track forecasts tend to be more sensitive to the low-level than to the upper-level wind observations. This indicates that the far-field low-level observations can improve the large-scale environmental flow that storms are to move in, giving rise to a better representation of the steering flow and subsequent intensity change. While much of the recent effort in tropical cyclone research focuses on inner-core observations to improve the intensity forecast, the results in this study show that the peripheral observations outside the storm center could contribute considerably to the intensity and track forecasts and deserve attention for better typhoon forecast skills.


2007 ◽  
Vol 14D (7) ◽  
pp. 801-808
Author(s):  
Ki-Hong Ko ◽  
Seong-Whan Kim
Keyword(s):  

Author(s):  
J. Carreira ◽  
E. Ekmekcioglu ◽  
A. Kondoz ◽  
P. Assuncao ◽  
S. Faria ◽  
...  

2005 ◽  
Vol 44 (S 01) ◽  
pp. S46-S50 ◽  
Author(s):  
M. Dawood ◽  
N. Lang ◽  
F. Büther ◽  
M. Schäfers ◽  
O. Schober ◽  
...  

Summary:Motion in PET/CT leads to artifacts in the reconstructed PET images due to the different acquisition times of positron emission tomography and computed tomography. The effect of motion on cardiac PET/CT images is evaluated in this study and a novel approach for motion correction based on optical flow methods is outlined. The Lukas-Kanade optical flow algorithm is used to calculate the motion vector field on both simulated phantom data as well as measured human PET data. The motion of the myocardium is corrected by non-linear registration techniques and results are compared to uncorrected images.


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