[301] | 1 | // ----------------------------------------------------------------------- |
---|
| 2 | // GaussSmooth.cc: Member functions for the GaussSmooth class. |
---|
| 3 | // ----------------------------------------------------------------------- |
---|
| 4 | // Copyright (C) 2006, Matthew Whiting, ATNF |
---|
| 5 | // |
---|
| 6 | // This program is free software; you can redistribute it and/or modify it |
---|
| 7 | // under the terms of the GNU General Public License as published by the |
---|
| 8 | // Free Software Foundation; either version 2 of the License, or (at your |
---|
| 9 | // option) any later version. |
---|
| 10 | // |
---|
| 11 | // Duchamp is distributed in the hope that it will be useful, but WITHOUT |
---|
| 12 | // ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
---|
| 13 | // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
---|
| 14 | // for more details. |
---|
| 15 | // |
---|
| 16 | // You should have received a copy of the GNU General Public License |
---|
| 17 | // along with Duchamp; if not, write to the Free Software Foundation, |
---|
| 18 | // Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA |
---|
| 19 | // |
---|
| 20 | // Correspondence concerning Duchamp may be directed to: |
---|
| 21 | // Internet email: Matthew.Whiting [at] atnf.csiro.au |
---|
| 22 | // Postal address: Dr. Matthew Whiting |
---|
| 23 | // Australia Telescope National Facility, CSIRO |
---|
| 24 | // PO Box 76 |
---|
| 25 | // Epping NSW 1710 |
---|
| 26 | // AUSTRALIA |
---|
| 27 | // ----------------------------------------------------------------------- |
---|
[275] | 28 | #include <iostream> |
---|
| 29 | #include <math.h> |
---|
[393] | 30 | #include <duchamp/Utils/GaussSmooth.hh> |
---|
[275] | 31 | |
---|
| 32 | GaussSmooth::GaussSmooth() |
---|
| 33 | { |
---|
| 34 | allocated=false; |
---|
[419] | 35 | } |
---|
| 36 | |
---|
[275] | 37 | GaussSmooth::~GaussSmooth() |
---|
| 38 | { |
---|
| 39 | if(allocated) delete [] kernel; |
---|
[419] | 40 | } |
---|
[275] | 41 | |
---|
[365] | 42 | GaussSmooth::GaussSmooth(const GaussSmooth& g) |
---|
| 43 | { |
---|
| 44 | operator=(g); |
---|
| 45 | } |
---|
| 46 | |
---|
| 47 | GaussSmooth& GaussSmooth::operator=(const GaussSmooth& g) |
---|
| 48 | { |
---|
| 49 | if(this==&g) return *this; |
---|
| 50 | this->kernMaj = g.kernMaj; |
---|
| 51 | this->kernMin = g.kernMin; |
---|
| 52 | this->kernPA = g.kernPA; |
---|
| 53 | this->kernWidth = g.kernWidth; |
---|
| 54 | this->stddevScale = g.stddevScale; |
---|
| 55 | this->allocated = g.allocated; |
---|
| 56 | if(this->allocated){ |
---|
| 57 | this->kernel = new float[this->kernWidth*this->kernWidth]; |
---|
| 58 | for(int i=0;i<this->kernWidth*this->kernWidth;i++) |
---|
| 59 | this->kernel[i] = g.kernel[i]; |
---|
| 60 | } |
---|
| 61 | return *this; |
---|
| 62 | } |
---|
| 63 | |
---|
[275] | 64 | GaussSmooth::GaussSmooth(float maj, float min, float pa) |
---|
| 65 | { |
---|
| 66 | this->allocated=false; |
---|
| 67 | this->define(maj, min, pa); |
---|
[419] | 68 | } |
---|
[275] | 69 | |
---|
| 70 | GaussSmooth::GaussSmooth(float maj) |
---|
| 71 | { |
---|
| 72 | this->allocated=false; |
---|
| 73 | this->define(maj, maj, 0); |
---|
[419] | 74 | } |
---|
[275] | 75 | |
---|
| 76 | void GaussSmooth::define(float maj, float min, float pa) |
---|
| 77 | { |
---|
| 78 | |
---|
| 79 | this->kernMaj = maj; |
---|
| 80 | this->kernMin = min; |
---|
| 81 | this->kernPA = pa; |
---|
| 82 | |
---|
| 83 | // The parameters kernMaj & kernMin are the FWHM in the major and |
---|
| 84 | // minor axis directions. We correct these to the sigma_x and |
---|
| 85 | // sigma_y parameters for the 2D gaussian by halving and dividing by |
---|
| 86 | // sqrt(2 ln(2)). Actually work with sigma_x^2 to make things |
---|
| 87 | // easier. |
---|
| 88 | float sigmaX2 = (this->kernMaj*this->kernMaj/4.) / (2.*M_LN2); |
---|
| 89 | float sigmaY2 = (this->kernMin*this->kernMin/4.) / (2.*M_LN2); |
---|
| 90 | |
---|
| 91 | // First determine the size of the kernel. |
---|
| 92 | // For the moment, just calculate the size based on the number of |
---|
| 93 | // pixels needed to make the exponential drop to less than the |
---|
| 94 | // stated precision. Use the major axis to get the largest square |
---|
| 95 | // that includes the ellipse. |
---|
| 96 | const float precision = 1.e-4; |
---|
| 97 | int kernelHW = int(ceil(sqrt(-1.*log(precision)*sigmaX2))); |
---|
| 98 | this->kernWidth = 2*kernelHW + 1; |
---|
[278] | 99 | // std::cerr << "Making a kernel of width " << this->kernWidth << "\n"; |
---|
[275] | 100 | |
---|
| 101 | if(this->allocated) delete [] this->kernel; |
---|
| 102 | this->kernel = new float[this->kernWidth*this->kernWidth]; |
---|
| 103 | this->allocated = true; |
---|
| 104 | this->stddevScale=0.; |
---|
| 105 | float posang = this->kernPA * M_PI/180.; |
---|
| 106 | |
---|
| 107 | |
---|
| 108 | for(int i=0;i<this->kernWidth;i++){ |
---|
| 109 | for(int j=0;j<this->kernWidth;j++){ |
---|
| 110 | float xpt = (i-kernelHW)*sin(posang) - (j-kernelHW)*cos(posang); |
---|
| 111 | |
---|
| 112 | float ypt = (i-kernelHW)*cos(posang) + (j-kernelHW)*sin(posang); |
---|
| 113 | float rsq = (xpt*xpt/sigmaX2) + (ypt*ypt/sigmaY2); |
---|
| 114 | kernel[i*this->kernWidth+j] = exp( -0.5 * rsq); |
---|
| 115 | this->stddevScale += |
---|
| 116 | kernel[i*this->kernWidth+j]*kernel[i*this->kernWidth+j]; |
---|
| 117 | } |
---|
| 118 | } |
---|
| 119 | this->stddevScale = sqrt(this->stddevScale); |
---|
[278] | 120 | // std::cerr << "Stddev scaling factor = " << this->stddevScale << "\n"; |
---|
[275] | 121 | } |
---|
| 122 | |
---|
| 123 | float *GaussSmooth::smooth(float *input, int xdim, int ydim) |
---|
| 124 | { |
---|
| 125 | /** |
---|
| 126 | * Smooth a given two-dimensional array, of dimensions xdim |
---|
| 127 | * \f$\times\f$ ydim, with an elliptical gaussian. Simply runs as a |
---|
| 128 | * front end to GaussSmooth::smooth(float *, int, int, bool *) by |
---|
| 129 | * defining a mask that allows all pixels in the input array. |
---|
| 130 | * |
---|
| 131 | * \param input The 2D array to be smoothed. |
---|
| 132 | * \param xdim The size of the x-dimension of the array. |
---|
| 133 | * \param ydim The size of the y-dimension of the array. |
---|
| 134 | * \return The smoothed array. |
---|
| 135 | */ |
---|
| 136 | float *smoothed; |
---|
| 137 | bool *mask = new bool[xdim*ydim]; |
---|
| 138 | for(int i=0;i<xdim*ydim;i++) mask[i]=true; |
---|
| 139 | smoothed = this->smooth(input,xdim,ydim,mask); |
---|
| 140 | delete [] mask; |
---|
| 141 | return smoothed; |
---|
| 142 | } |
---|
| 143 | |
---|
| 144 | float *GaussSmooth::smooth(float *input, int xdim, int ydim, bool *mask) |
---|
| 145 | { |
---|
| 146 | /** |
---|
| 147 | * Smooth a given two-dimensional array, of dimensions xdim |
---|
| 148 | * \f$\times\f$ ydim, with an elliptical gaussian, where the |
---|
| 149 | * boolean array mask defines which values of the array are valid. |
---|
| 150 | * |
---|
| 151 | * This function convolves the input array with the kernel that |
---|
| 152 | * needs to have been defined. If it has not, the input array is |
---|
| 153 | * returned unchanged. |
---|
| 154 | * |
---|
| 155 | * The mask should be the same size as the input array, and have |
---|
| 156 | * values of true for entries that are considered valid, and false |
---|
| 157 | * for entries that are not. For instance, arrays from FITS files |
---|
| 158 | * should have the mask entries corresponding to BLANK pixels set |
---|
| 159 | * to false. |
---|
| 160 | * |
---|
| 161 | * \param input The 2D array to be smoothed. |
---|
| 162 | * \param xdim The size of the x-dimension of the array. |
---|
| 163 | * \param ydim The size of the y-dimension of the array. |
---|
| 164 | * \param mask The array showing which pixels in the input array |
---|
| 165 | * are valid. |
---|
| 166 | * \return The smoothed array. |
---|
| 167 | */ |
---|
| 168 | |
---|
| 169 | |
---|
| 170 | if(!this->allocated) return input; |
---|
| 171 | else{ |
---|
| 172 | |
---|
| 173 | float *output = new float[xdim*ydim]; |
---|
| 174 | |
---|
| 175 | int pos,comp,xcomp,ycomp,fpos,ct; |
---|
| 176 | float fsum; |
---|
| 177 | int kernelHW = this->kernWidth/2; |
---|
| 178 | |
---|
| 179 | for(int ypos = 0; ypos<ydim; ypos++){ |
---|
| 180 | for(int xpos = 0; xpos<xdim; xpos++){ |
---|
| 181 | pos = ypos*xdim + xpos; |
---|
| 182 | |
---|
| 183 | if(!mask[pos]) output[pos] = input[pos]; |
---|
| 184 | else{ |
---|
| 185 | |
---|
| 186 | ct=0; |
---|
| 187 | fsum=0.; |
---|
| 188 | output[pos] = 0.; |
---|
| 189 | |
---|
| 190 | for(int yoff = -kernelHW; yoff<=kernelHW; yoff++){ |
---|
| 191 | ycomp = ypos + yoff; |
---|
| 192 | if((ycomp>=0)&&(ycomp<ydim)){ |
---|
| 193 | |
---|
| 194 | for(int xoff = -kernelHW; xoff<=kernelHW; xoff++){ |
---|
| 195 | xcomp = xpos + xoff; |
---|
| 196 | if((xcomp>=0)&&(xcomp<xdim)){ |
---|
| 197 | |
---|
| 198 | fpos = (xoff+kernelHW) + (yoff+kernelHW)*this->kernWidth; |
---|
| 199 | comp = ycomp*xdim + xcomp; |
---|
| 200 | if(mask[comp]){ |
---|
| 201 | ct++; |
---|
| 202 | fsum += this->kernel[fpos]; |
---|
| 203 | output[pos] += input[comp]*this->kernel[fpos]; |
---|
| 204 | } |
---|
| 205 | |
---|
| 206 | } |
---|
| 207 | } // xoff loop |
---|
| 208 | |
---|
| 209 | } |
---|
| 210 | }// yoff loop |
---|
| 211 | if(ct>0) output[pos] /= fsum; |
---|
| 212 | |
---|
| 213 | } // else{ |
---|
| 214 | |
---|
| 215 | } //xpos loop |
---|
| 216 | } //ypos loop |
---|
| 217 | |
---|
| 218 | return output; |
---|
| 219 | } |
---|
| 220 | |
---|
| 221 | } |
---|