Quantum GIS API Documentation
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00001 /*************************************************************************** 00002 qgsruggednessfilter.cpp - description 00003 ----------------------- 00004 begin : August 7th, 2009 00005 copyright : (C) 2009 by Marco Hugentobler 00006 email : marco dot hugentobler at karto dot baug dot ethz dot ch 00007 ***************************************************************************/ 00008 00009 /*************************************************************************** 00010 * * 00011 * This program is free software; you can redistribute it and/or modify * 00012 * it under the terms of the GNU General Public License as published by * 00013 * the Free Software Foundation; either version 2 of the License, or * 00014 * (at your option) any later version. * 00015 * * 00016 ***************************************************************************/ 00017 00018 #include "qgsruggednessfilter.h" 00019 00020 QgsRuggednessFilter::QgsRuggednessFilter( const QString& inputFile, const QString& outputFile, const QString& outputFormat ): QgsNineCellFilter( inputFile, outputFile, outputFormat ) 00021 { 00022 00023 } 00024 00025 QgsRuggednessFilter::QgsRuggednessFilter(): QgsNineCellFilter( "", "", "" ) 00026 { 00027 00028 } 00029 00030 00031 QgsRuggednessFilter::~QgsRuggednessFilter() 00032 { 00033 00034 } 00035 00036 float QgsRuggednessFilter::processNineCellWindow( float* x11, float* x21, float* x31, 00037 float* x12, float* x22, float* x32, float* x13, float* x23, float* x33 ) 00038 { 00039 //the formula would be that easy without nodata values... 00040 /* 00041 //return *x22; //test: write the raster value of the middle cell 00042 float diff1 = *x11 - *x22; 00043 float diff2 = *x21 - *x22; 00044 float diff3 = *x31 - *x22; 00045 float diff4 = *x12 - *x22; 00046 float diff5 = *x32 - *x22; 00047 float diff6 = *x13 - *x22; 00048 float diff7 = *x23 - *x22; 00049 float diff8 = *x33 - *x22; 00050 return sqrt(diff1 * diff1 + diff2 * diff2 + diff3 * diff3 + diff4 * diff4 + diff5 * diff5 + diff6 * diff6 + diff7 * diff7 + diff8 * diff8); 00051 */ 00052 00053 if ( *x22 == mInputNodataValue ) 00054 { 00055 return mOutputNodataValue; 00056 } 00057 00058 double sum = 0; 00059 if ( *x11 != mInputNodataValue ) 00060 { 00061 sum += ( *x11 - *x22 ) * ( *x11 - *x22 ); 00062 } 00063 if ( *x21 != mInputNodataValue ) 00064 { 00065 sum += ( *x21 - *x22 ) * ( *x21 - *x22 ); 00066 } 00067 if ( *x31 != mInputNodataValue ) 00068 { 00069 sum += ( *x31 - *x22 ) * ( *x31 - *x22 ); 00070 } 00071 if ( *x12 != mInputNodataValue ) 00072 { 00073 sum += ( *x12 - *x22 ) * ( *x12 - *x22 ); 00074 } 00075 if ( *x32 != mInputNodataValue ) 00076 { 00077 sum += ( *x32 - *x22 ) * ( *x32 - *x22 ); 00078 } 00079 if ( *x13 != mInputNodataValue ) 00080 { 00081 sum += ( *x13 - *x22 ) * ( *x13 - *x22 ); 00082 } 00083 if ( *x23 != mInputNodataValue ) 00084 { 00085 sum += ( *x23 - *x22 ) * ( *x23 - *x22 ); 00086 } 00087 if ( *x33 != mInputNodataValue ) 00088 { 00089 sum += ( *x33 - *x22 ) * ( *x33 - *x22 ); 00090 } 00091 00092 return sqrt( sum ); 00093 } 00094