Automatic Change Detections from SAR Images Using Fractal Dimension

2006 ◽  
Author(s):  
Y. Tzeng ◽  
S. Chiu ◽  
K. Chen
Keyword(s):  
Fractal Dimension ◽  
Sar Images

The Role of Significant Digits of Fractal Dimension for the Measurement of Texture in SAR Images

2021 ◽  
Vol 11 (1) ◽  
pp. 80-96
Author(s):  
Triloki Pant
Keyword(s):  
Fractal Dimension ◽  
Synthetic Aperture Radar ◽  
Synthetic Aperture ◽  
Decimal Point ◽  
Sar Images ◽  
Texture Measurement ◽  
Calculated Ratio ◽  
Synthetic Images ◽  
Aperture Radar

The present work deals with fractal-based texture measurement of synthetic aperture radar (SAR) images. Various land classes have been identified by classifying SAR images, and the fractal dimension is estimated for differentiating the classes. Three types of SAR images, viz., synthetic images, simulated SAR images, and satellite SAR images, have been used in the study. An issue with fractal dimension-based measurement is how many digits after decimal point should be considered for estimating fractal dimension? Since fractal dimension is calculated as a ratio, the major challenge is the decidability of significant digits for land classes. The issue has been overcome by discussing the feasibility of fractal dimension for the land classes defined by USGS and the calculated ratio for 200×200 values. As an achievement of the work, it is concluded that two digits of the decimal are sufficient to represent the fractal dimension of land classes.

scholarly journals Fractal dimension images from SAR images

2014 ◽  
Author(s):  
Daniele Riccio ◽  
Gerardo Di Martino ◽  
Antonio Iodice ◽  
Giuseppe Ruello ◽  
Ivana Zinno
Keyword(s):  
Fractal Dimension ◽  
Sar Images

Use of fractals to describe microstructures of porous thick-film platinum electrodes

1992 ◽  
Vol 50 (1) ◽  
pp. 314-315
Author(s):  
Steven D. Toteda
Keyword(s):  
Fractal Dimension ◽  
Power Plants ◽  
Electrical Response ◽  
Cubic Phase ◽  
Platinum Electrodes ◽  
Fine Grained ◽  
Impedance Response ◽  
Platinum Particles ◽  
Energy Surfaces ◽  
Highly Porous

Zirconia oxygen sensors, in such applications as power plants and automobiles, generally utilize platinum electrodes for the catalytic reaction of dissociating O2 at the surface. The microstructure of the platinum electrode defines the resulting electrical response. The electrode must be porous enough to allow the oxygen to reach the zirconia surface while still remaining electrically continuous. At low sintering temperatures, the platinum is highly porous and fine grained. The platinum particles sinter together as the firing temperatures are increased. As the sintering temperatures are raised even further, the surface of the platinum begins to facet with lower energy surfaces. These microstructural changes can be seen in Figures 1 and 2, but the goal of the work is to characterize the microstructure by its fractal dimension and then relate the fractal dimension to the electrical response. The sensors were fabricated from zirconia powder stabilized in the cubic phase with 8 mol% percent yttria. Each substrate was sintered for 14 hours at 1200°C. The resulting zirconia pellets, 13mm in diameter and 2mm in thickness, were roughly 97 to 98 percent of theoretical density. The Engelhard #6082 platinum paste was applied to the zirconia disks after they were mechanically polished ( diamond). The electrodes were then sintered at temperatures ranging from 600°C to 1000°C. Each sensor was tested to determine the impedance response from 1Hz to 5,000Hz. These frequencies correspond to the electrode at the test temperature of 600°C.

Comment on "On the fractal dimension of stream networks"

1990 ◽  
Vol 26 (9) ◽  
pp. 2243-2244 ◽  
Author(s):  
David G. Tarboton
Keyword(s):  
Fractal Dimension ◽  
Stream Networks

Heterogeneity of Cerebral Blood Flow: a Fractal Approach

2000 ◽  
Vol 39 (02) ◽  
pp. 37-42 ◽  
Author(s):  
P. Hartikainen ◽  
J. T. Kuikka
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Fractal Dimension ◽  
Frontal Lobe ◽  
Fractal Analysis ◽  
Relative Dispersion ◽  
Emission Computed Tomography ◽  
Brain Blood Flow ◽  
Healthy Controls ◽  
Fractal Approach

Summary Aim: We demonstrate the heterogeneity of regional cerebral blood flow using a fractal approach and singlephoton emission computed tomography (SPECT). Method: Tc-99m-labelled ethylcysteine dimer was injected intravenously in 10 healthy controls and in 10 patients with dementia of frontal lobe type. The head was imaged with a gamma camera and transaxial, sagittal and coronal slices were reconstructed. Two hundred fifty-six symmetrical regions of interest (ROIs) were drawn onto each hemisphere of functioning brain matter. Fractal analysis was used to examine the spatial heterogeneity of blood flow as a function of the number of ROIs. Results: Relative dispersion (= coefficient of variation of the regional flows) was fractal-like in healthy subjects and could be characterized by a fractal dimension of 1.17 ± 0.05 (mean ± SD) for the left hemisphere and 1.15 ± 0.04 for the right hemisphere, respectively. The fractal dimension of 1.0 reflects completely homogeneous blood flow and 1.5 indicates a random blood flow distribution. Patients with dementia of frontal lobe type had a significantly lower fractal dimension of 1.04 ± 0.03 than in healthy controls. Conclusion: Within the limits of spatial resolution of SPECT, the heterogeneity of brain blood flow is well characterized by a fractal dimension. Fractal analysis may help brain scientists to assess age-, sex- and laterality-related anatomic and physiological changes of brain blood flow and possibly to improve precision of diagnostic information available for patient care.

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