libs/gil/doc/html/_downloads/convolution.cpp

   1 //
   2 // Copyright 2005-2007 Adobe Systems Incorporated
   3 //
   4 // Distributed under the Boost Software License, Version 1.0
   5 // See accompanying file LICENSE_1_0.txt or copy at
   6 // http://www.boost.org/LICENSE_1_0.txt
   7 #include <boost/gil.hpp>
   8 #include <boost/gil/extension/io/jpeg.hpp>
   9 #include <boost/gil/extension/numeric/kernel.hpp>
  10 #include <boost/gil/extension/numeric/convolve.hpp>
  11
  12 // Example for convolve_rows() and convolve_cols() in the numeric extension
  13
  14 int main() {
  15     using namespace boost::gil;
  16
  17     rgb8_image_t img;
  18     read_image("test.jpg", img, jpeg_tag{});
  19
  20     // Convolve the rows and the columns of the image with a fixed kernel
  21     rgb8_image_t convolved(img);
  22
  23     // radius-1 Gaussian kernel, size 9
  24     float gaussian_1[]={0.00022923296f,0.0059770769f,0.060597949f,0.24173197f,0.38292751f,
  25                         0.24173197f,0.060597949f,0.0059770769f,0.00022923296f};
  26     /*
  27     // radius-2 Gaussian kernel, size 15
  28     float gaussian_2[]={
  29         0.00048869418f,0.0024031631f,0.0092463447f,
  30         0.027839607f,0.065602221f,0.12099898f,0.17469721f,
  31         0.19744757f,
  32         0.17469721f,0.12099898f,0.065602221f,0.027839607f,
  33         0.0092463447f,0.0024031631f,0.00048869418f
  34     };
  35     //radius-3 Gaussian kernel, size 23
  36     float gaussian_3[]={
  37         0.00016944126f,0.00053842377f,0.0015324751f,0.0039068931f,
  38         0.0089216027f,0.018248675f,0.033434924f,0.054872241f,
  39         0.080666073f,0.10622258f,0.12529446f,
  40         0.13238440f,
  41         0.12529446f,0.10622258f,0.080666073f,
  42         0.054872241f,0.033434924f,0.018248675f,0.0089216027f,
  43         0.0039068931f,0.0015324751f,0.00053842377f,0.00016944126f
  44     };
  45     //radius-4 Gaussian kernel, size 29
  46     float gaussian_4[]={
  47         0.00022466264f,0.00052009715f,0.0011314391f,0.0023129794f,
  48         0.0044433107f,0.0080211498f,0.013606987f,0.021691186f,
  49         0.032493830f,0.045742013f,0.060509924f,0.075220309f,
  50         0.087870099f,0.096459411f,0.099505201f,0.096459411f,0.087870099f,
  51         0.075220309f,0.060509924f,0.045742013f,0.032493830f,
  52         0.021691186f,0.013606987f,0.0080211498f,0.0044433107f,
  53         0.0023129794f,0.0011314391f,0.00052009715f,0.00022466264f,
  54     };
  55     */
  56
  57     kernel_1d_fixed<float,9> kernel(gaussian_1,4);
  58     convolve_rows_fixed<rgb32f_pixel_t>(const_view(convolved),kernel,view(convolved));
  59     convolve_cols_fixed<rgb32f_pixel_t>(const_view(convolved),kernel,view(convolved));
  60     write_view("out-convolution.jpg", view(convolved), jpeg_tag{});
  61
  62     // This is how to use a resizable kernel
  63     kernel_1d<float> kernel2(gaussian_1,9,4);
  64     convolve_rows<rgb32f_pixel_t>(const_view(img),kernel2,view(img));
  65     convolve_cols<rgb32f_pixel_t>(const_view(img),kernel2,view(img));
  66     write_view("out-convolution2.jpg", view(img), jpeg_tag{});
  67
  68     return 0;
  69 }