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Range estimation from Intensity Gradient Analysis

Kurt Skifstad, Ramesh Jain
1989 Machine Vision and Applications  
The Intensity Gradient Analysis technique (IGA) is a depth recovery algorithm that exploits the properties of the MCSO (moving camera, stationary objects) scenario.  ...  Depth values are obtained by analyzing temporal intensity gradients arising from the optic flow field induced by known camera motion.  ...  The Intensity Gradient Analysis technique (IGA) also uses temporal intensity gradients, but purely on a local level.  ... 
doi:10.1007/bf01212370 fatcat:ush5svkvvvhlhfucakj4cxspoe

Range estimation from intensity gradient analysis

K. Skifstad, R. Jain
Proceedings, 1989 International Conference on Robotics and Automation  
The Intensity Gradient Analysis technique (IGA) is a depth recovery algorithm that exploits the properties of the MCSO (moving camera, stationary objects) scenario.  ...  Depth values are obtained by analyzing temporal intensity gradients arising from the optic flow field induced by known camera motion.  ...  The Intensity Gradient Analysis technique (IGA) also uses temporal intensity gradients, but purely on a local level.  ... 
doi:10.1109/robot.1989.99965 dblp:conf/icra/SkifstadJ89 fatcat:kjvkiz34wbedvkubw4ve7uerqa

A computational statistics approach for estimating the spatial range of morphogen gradients

J. S. Kanodia, Y. Kim, R. Tomer, Z. Khan, K. Chung, J. D. Storey, H. Lu, P. J. Keller, S. Y. Shvartsman
2011 Development  
A crucial issue in studies of morphogen gradients relates to their range: the distance over which they can act as direct regulators of cell signaling, gene expression and cell differentiation.  ...  We illustrate the developed approach by providing a point estimate and confidence interval for the spatial range of the graded distribution of nuclear Dorsal, a transcription factor that controls the dorsoventral  ...  Our analysis of multiple independent experiments suggests that an accurate estimate for the range can be based on data from 50-70 gradients.  ... 
doi:10.1242/dev.071571 pmid:22007136 pmcid:PMC3201657 fatcat:kzk5foqp7ne6jh7ttoy44b3oka

Colonyzer: automated quantification of micro-organism growth characteristics on solid agar

Conor Lawless, Darren J Wilkinson, Alexander Young, Stephen G Addinall, David A Lydall
2010 BMC Bioinformatics  
In order to parametrize such a model, a robust image analysis tool capable of capturing a wide range of cell densities from plate photographs is required.  ...  Colonyzer is robust to slight experimental imperfections and corrects for lighting gradients which would otherwise introduce spatial bias to cell density estimates without the need for imaging dummy plates  ...  In this way the pixels whose intensity gradient is in the top 5% for the colonies are cut out (the edges have been masked).  For each approximate rectangular tile location, as estimated from the user  ... 
doi:10.1186/1471-2105-11-287 pmid:20509870 pmcid:PMC2901369 fatcat:nl7igdjawjhofhh5crz6lqsq3i

Effects of Gradient Coil Noise and Gradient Coil Replacement on the Reproducibility of Resting State Networks

Epifanio Bagarinao, Erina Tsuzuki, Yukina Yoshida, Yohei Ozawa, Maki Kuzuya, Takashi Otani, Shuji Koyama, Haruo Isoda, Hirohisa Watanabe, Satoshi Maesawa, Shinji Naganawa, Gen Sobue
2018 Frontiers in Human Neuroscience  
In this article, we examined the effect of low intensity, randomly occurring hardware-related noise due to a faulty gradient coil on brain morphometric measures derived from T1-weighted images and resting  ...  However, censoring the affected volumes during the analysis could minimize, if not completely eliminate, these spurious connectivity changes and could lead to reproducible RSNs even after gradient coil  ...  (A) Slices 5, 17, 30 and 33 displayed using intensity values ranging from 10 to 1000.  ... 
doi:10.3389/fnhum.2018.00148 pmid:29725294 pmcid:PMC5917444 fatcat:ldtmojrw45es5dumemr53wc6tq

A Quality Pre-processor for Biological Cell Images [chapter]

Adele P. Peskin, Karen Kafadar, Alden Dima
2009 Lecture Notes in Computer Science  
This method is based on the gradient of the pixel intensity field at cell edges and on the distribution of pixel intensities just inside cell edges.  ...  The data for Table 2 refer to estimates from the 3-component model for the distribution of pixel intensities (background, cell, edge) for a single cell chosen from each image.  ...  We then test the new image by recalculating the 3-component analysis, pixel intensity gradient, and quality to ensure that it retained the same features.  ... 
doi:10.1007/978-3-642-10520-3_101 fatcat:7vth62mfcfau7aq4wqnvohgup4

Hydraulic conditions in experimental rill confluences and scour in erodible soils

Rorke B. Bryan, Nikolaus J. Kuhn
2002 Water Resources Research  
Rainfall intensity showed more importance than the slope gradient in the point of rill formation.  ...  The point of rills formation (slope length) decreases with an increase in slope gradient and rainfall intensity.  ...  Results of variance analysis of the variables Runoff start time, Rill start time, and slope gradient) were estimated in Fig. 5c .  ... 
doi:10.1029/2000wr000140 fatcat:ujfwkljmuzg7xntcwfyxtwv4vi

Improving Accuracy and Robustness of Space-Time Image Velocimetry (STIV) with Deep Learning

Ken Watanabe, Ichiro Fujita, Makiko Iguchi, Makoto Hasegawa
2021 Water  
In this study, we tried to solve this problem by incorporating the deep learning method, which has been successful in the field of image analysis in recent years, into the STIV method.  ...  However, depending on the image shooting environment such as stormy weather or nighttime, the conventional automatic analysis methods may generate incorrect values, which has been a problem in building  ...  However, in this study, we classify the range from 0° to 180° into classes with a specific incremental range and train the CNN as a classification problem to estimate the corresponding gradient class from  ... 
doi:10.3390/w13152079 fatcat:zylbs6h3mbal5kuhelmzggrygq

The radial diffusion coefficient of 1.3- 23 MeV protons in recurrent proton streams

R. A. Mewaldt, E. C. Stone, R. E. Vogt
1978 Geophysical Research Letters  
The resulting values for • near 1 AU range from (3 to 9) x 1020 cm2/sec, rr corresponding to scattering mean free paths between 0.03 and 0.1 AU.  ...  Direct estimates of the radial diffusion coefficient • for 1.3-2.3 MeV protons in rr interplanetary space are made by comparing simultaneous observations of the diffusive anisotropy and radial gradient  ...  Another method for estimating • is to fit the from 1967-1974 over the rigidity range from ~ 1 to 3000 MV.  ... 
doi:10.1029/gl005i011p00965 fatcat:dyqfgeq75vchvovvh56ikm7mxm

A fast model independent method for automatic correction of intensity nonuniformity in MRI data

Elizabeth A. Vokurka, Neil A. Thacker, Alan Jackson
1999 Journal of Magnetic Resonance Imaging  
All magnetic resonance images suffer from signal intensity non-uniformity to some extent causing a smooth drift of average intensity across constant regions of tissue.  ...  Radio frequency (RF) coil asymmetry, gradient-driven eddy currents, pulse sequence parameters, and overall patient anatomy all potentially contribute to this gain drift [3].  ...  Identical slices are multiplied by a sinusoidal gains ranging from 50% to 150% intensity of the image. Random noise of 20% of white matter peak intensity is added to each of the images in the series.  ... 
doi:10.1002/(sici)1522-2586(199910)10:4<550::aid-jmri8>;2-q pmid:10508322 fatcat:yg4udnqswvgspbplkjmq6xxbmi

Asymmetric tropospheric delays from numerical weather models for UT1 determination from VLBI Intensive sessions on the baseline Wettzell–Tsukuba

Johannes Böhm, T. Hobiger, R. Ichikawa, T. Kondo, Y. Koyama, A. Pany, H. Schuh, K. Teke
2010 Journal of Geodesy  
(LOD) estimates from Global Positioning System (GPS) indicate that these ray-traced delays slightly improve the UT1 estimates from Intensive sessions.  ...  Spectral analysis reveals that delays from direct ray-tracing for the station Tsukuba add significant power at short periods (1-2 weeks) w.r.t. the state-of-the-art approach, and comparisons with length-of-day  ...  We would also like to thank Peter Steigenberger for providing the GPS gradients for Tsukuba. Andrea Pany is recipient of a DOC-fFORTE fellowship  ... 
doi:10.1007/s00190-010-0370-x fatcat:odovi43rxfg5xbfoox4a7wgwhm


2001 International Journal of Image and Graphics  
Towards shape analysis gradient-oriented profiles are applied to medial primitives known as core atoms.  ...  Every profile is analyzed via nonlinear optimization to fit the best cumulative Gaussian, directly parameterizing the boundary to yield estimates of (1) extrapolated intensity values for voxels located  ...  Acknowledgments This work was funded by grants from the Whitaker Foundation and the National Library of Medicine Insight Toolkit (ITK) project.  ... 
doi:10.1142/s0219467801000360 fatcat:dl2w5fkbnnhqjcg7ojvcocch2m

Determination of Geothermal Energy Sources in Masu Area Northeastern Nigeria Using Spectral Analysis of Aeromagnetic Data

Moses Akiishi
2018 International Journal of Energy and Environmental Science  
The Curie point depth obtained ranges from 12.233 to 16.184 km with an average of 13.993 km, the geothermal gradient of the area varies from 35.838 to 47.413°C /km, with an average of 41.821°C /km, while  ...  the heat flow ranges from 89 to 117.80 mWm -2 , with an average of 104.551 mWm -2 .  ...  The geothermal gradient of the area ranges from 35.84 to 47.41°C /km, with an average of 41.82°C /km.  ... 
doi:10.11648/j.ijees.20180305.11 fatcat:5wa2cbdjgrednhbbyb5y3dmaoe

Characterization of free volume and density gradients of polystyrene surfaces by low-energy positron lifetime measurements

2004 Polymer  
Moreover, the spectra in the low implantation energy range were found to contain a long-lived lifetime that yielded very large estimates of the free volume effects at the surface.  ...  A density gradient in terms of mass density (g/cm 3 ) versus depth (nm) was obtained from the experimental beam data using a novel approach, yielding a width of the density gradient of approximately 3.5  ...  If the t 3 results of the FGGF analysis are used as the free volume probe, however, the corresponding width of the density gradient is estimated to be 8 nm, more than twice as large.  ... 
doi:10.1016/s0032-3861(04)00371-4 fatcat:anpmwpu7ive5rhj2vftketr6lu

Material and shape perception based on two types of intensity gradient information

Masataka Sawayama, Shin'ya Nishida, Wolfgang Einhäuser
2018 PLoS Computational Biology  
on the intensity gradient order information.  ...  Visual estimation of the material and shape of an object from a single image includes a hard ill-posed computational problem. However, in our daily life we feel we can estimate both reasonably well.  ...  to estimate material only from the intensity gradient magnitude information.  ... 
doi:10.1371/journal.pcbi.1006061 pmid:29702644 pmcid:PMC5963816 fatcat:utelqblycbgvzf4bi6hmgxwktm
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