Image Sequence Enhancements Based on the Normal Component of Image Motion

1982 ◽  
Author(s):  
Larry S. Davis ◽  
Hu-chen Xie ◽  
Azriel Rosenfeld
1983 ◽  
Vol 2 (2) ◽  
pp. 95-99 ◽  
Author(s):  
Larry S Davis ◽  
Hu-chen Xie ◽  
Azriel Rosenfeld

2010 ◽  
Vol 121-122 ◽  
pp. 476-481 ◽  
Author(s):  
Yi Gang Wang ◽  
Gang Yi Jiang ◽  
Mei Yu

In order to obtain panoramic view of medical micro-image in remote medical diagnosis system, we should mosaic micro-image sequence accurately in remote node. SIFT features are invariant to image scaling, rotation and translation. The aim of this study is to mosaic micro-image sequence by extracting SIFT features. Firstly, search coordinate of potential features through Gaussian pyramid (with 7 octaves × 6 scales) and then filter pseudo-keypoints. Secondly, describe these features with 128-D vector. The next step is to calculate matching keypoint pairs between two time-successive images according to minimum Euclidean distance. In this step, standard deviation comparing is proposed to eliminate wrong matching pairs and appropriate threshold(8000) through experiment is used to insure matching pairs. Then, construct image motion equation considering rotation and translation and compute motion parameter by solving equation according matching pairs. Finally mosaic all images. These steps are applied in 5 micro-image sequences such as slices of lung tissue, spleen, kidney, frog blood cell and sunflower tissue. The experiment results show that the gap between two images is vanishing and the proposed method can satisfy with medical micro-images sequence mosaic.


Author(s):  
MP Ramachandran ◽  
MK Agarwal ◽  
DA Daniel

Image registration is important in geostationary weather satellites. Achieving consistent registration of the images with respect to the geographical locations on the Earth is here of interest. The consistency in the registration between the images is affected whenever the orbital inclination and eccentricity are not zero. The imaging payload has a two-axis scanning mirror to capture the Earth image. The above orbital effects together with scan mirror pointing direction are the factors that cause the misregistration. This paper presents an onboard algorithm that provides the scan compensation angles due to the above factors and achieves consistent registration. The compensation varies every second, which is the time taken for each scan. Hence it is preferred to have computations onboard than to have ground based bulk uplinks for the scan compensation. The paper presents an algorithm that is useful, say, when (i) the onboard computing capabilities are limited, (ii) the navigation accuracies are coarse and (iii) the image resampling is not preferred on the ground and the payload data are directly used for weather applications. The paper also discusses the tests that were carried on the onboard software in order to validate its performance in achieving the consistent registration before launch. This is done by using another independent software tool which is also described in detail. Image motion algorithm was invoked for a couple of days in INSAT 3DR. The atmospheric wind vector deduced directly from the satellite images is given at the end.


2020 ◽  
Vol 500 (2) ◽  
pp. 1884-1888
Author(s):  
Mohammed Sabil ◽  
A Habib ◽  
Z Benkhaldoun

ABSTRACT In this work, we aim to calibrate an interferential seeing monitor (ISM), which is a testing instument used at astronomical sites. Its method is based on the study of the diffraction pattern produced by a Young’s double-slit at the focus plane of a telescope. This method allows us to obtain the wave structure function by taking into account both phase and amplitude fluctuations of the light wavefront. A phase seeing εϕ was assigned to phase fluctuations and an amplitude seeing εχ was assigned to amplitude fluctuations (scintillation phenomenon), which allows us to obtain both phase and amplitude fluctuations. The feasibility of the ISM method was demonstrated by numerical simulations presented in a previous work. In this work, we have conducted a cross-calibration campaign of the ISM with a differential image motion monitor (DIMM) over 16 nights at the Oukaimeden and Atlas Golf Marrakech Observatories. The goal of this campaign was to study the reliability of this new method. In this paper, we present the calibration measurements and a comparison between the seeing measured by the ISM (εϕ, εχ) and that obtained by the DIMM (εdimm). These results show good agreement between the phase- eeing εϕ and εdimm.


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