5 billion U.S. dollars [3, 5, 10].This research investigates the earthquake induced changes in the city center of Adapazari where the recorded number of collapsed buildings was 11,373 [5]. The district of Adapazari is located in the northeastern these part of the Marmara Region, Turkey, covering 29��57��C30��53�� N and 40�� 17��C41��13�� E. The population of the Adapazari inner city was 169,099, 184,013, and 172,000 in 1990, 1997, and 2000, respectively [11].SPOT HRVIR panchromatic images obtained before (25 June 1999) and after (4 October 1999) the earthquake were used in the research. These images have 10 m spatial and 8 bit radiometric resolution. The 1/5,000 scale digital damage map illustrating the degree of earthquake damage was used to analyze the accuracy of the proposed method.

This map was produced by local and federal authorities by conducting a field survey on the building base after the earthquake.3.?Methodology3.1. Radiometric Normalization and Geometric CorrectionBoth images were first geometrically corrected into Universal Transverse Mercator (UTM) projection Inhibitors,Modulators,Libraries using first order polynomials and appropriate Ground Control Points (GCP) collected from topographic maps. Then, radiometric normalization was employed using a histogram matching algorithm.3.2. Fourier TransformAny one-dimensional function, f(x) (which might be a row or column of pixels), can be represented by a Fourier series composed of some sine and cosine terms and their associated coefficients combination. Different spatial frequencies over an image can be represented by many sine and cosine terms and with their associated coefficients.

Fourier series are effective to Inhibitors,Modulators,Libraries identify and quantify spatial frequencies [12,13]. Since an earthquake changes the spatial structure of a related area because Inhibitors,Modulators,Libraries of collapsed or damaged buildings, roads etc., Fourier series can be used to identify different spatial frequencies in images obtained before and after the earthquake which indeed lead information about the earthquake-induced Inhibitors,Modulators,Libraries damages.The Fast Fourier Transform (FFT) calculation used in this research is shown in the equation 1 [12]:F(u,v)����x=0M?1��y=0N?1[f(x,y)e?j2��uxM?j2��vyN](1)where:M = the number of pixels horizontallyN = the number of pixels verticallyu,v = spatial frequency variablese = 2.

71828, the natural logarithm basej = the imaginary component of a complex numberOnce the FFT is applied, a raster image from the spatial domain is converted into a frequency domain image. The Fourier Brefeldin_A image can be edited (mainly using filters) to reduce noise, to identify specific features or to remove periodic features. After editing the Fourier image, it is transformed back into spatial domain using Inverse Fast Fourier selleck products Transform (IFFT) equation (Equation 2) [12]:f(x,y)��1N1N2��u=0M?1��v=0N?1[F(u,v)ej2��uxM+j2��vyN]0��x��M?1,0��y��N?1(2)3.3. Difference Image and Level SlicingA difference image was calculated by subtracting the inverse Fourier transformed post- and pre-earthquake images.