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<div class="fragment"><div class="line"><a name="l00001"></a><span class="lineno">    1</span>&#160;<span class="comment">//</span></div><div class="line"><a name="l00002"></a><span class="lineno">    2</span>&#160;<span class="comment">// Copyright 2019 Miral Shah &lt;miralshah2211@gmail.com&gt;</span></div><div class="line"><a name="l00003"></a><span class="lineno">    3</span>&#160;<span class="comment">//</span></div><div class="line"><a name="l00004"></a><span class="lineno">    4</span>&#160;<span class="comment">// Use, modification and distribution are subject to the Boost Software License,</span></div><div class="line"><a name="l00005"></a><span class="lineno">    5</span>&#160;<span class="comment">// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at</span></div><div class="line"><a name="l00006"></a><span class="lineno">    6</span>&#160;<span class="comment">// http://www.boost.org/LICENSE_1_0.txt)</span></div><div class="line"><a name="l00007"></a><span class="lineno">    7</span>&#160;<span class="comment">//</span></div><div class="line"><a name="l00008"></a><span class="lineno">    8</span>&#160;</div><div class="line"><a name="l00009"></a><span class="lineno">    9</span>&#160;<span class="preprocessor">#ifndef BOOST_GIL_IMAGE_PROCESSING_FILTER_HPP</span></div><div class="line"><a name="l00010"></a><span class="lineno">   10</span>&#160;<span class="preprocessor">#define BOOST_GIL_IMAGE_PROCESSING_FILTER_HPP</span></div><div class="line"><a name="l00011"></a><span class="lineno">   11</span>&#160;</div><div class="line"><a name="l00012"></a><span class="lineno">   12</span>&#160;<span class="preprocessor">#include &lt;boost/gil/extension/numeric/algorithm.hpp&gt;</span></div><div class="line"><a name="l00013"></a><span class="lineno">   13</span>&#160;<span class="preprocessor">#include &lt;boost/gil/extension/numeric/kernel.hpp&gt;</span></div><div class="line"><a name="l00014"></a><span class="lineno">   14</span>&#160;<span class="preprocessor">#include &lt;boost/gil/extension/numeric/convolve.hpp&gt;</span></div><div class="line"><a name="l00015"></a><span class="lineno">   15</span>&#160;</div><div class="line"><a name="l00016"></a><span class="lineno">   16</span>&#160;<span class="preprocessor">#include &lt;boost/gil/image.hpp&gt;</span></div><div class="line"><a name="l00017"></a><span class="lineno">   17</span>&#160;<span class="preprocessor">#include &lt;boost/gil/image_view.hpp&gt;</span></div><div class="line"><a name="l00018"></a><span class="lineno">   18</span>&#160;</div><div class="line"><a name="l00019"></a><span class="lineno">   19</span>&#160;<span class="preprocessor">#include &lt;cstddef&gt;</span></div><div class="line"><a name="l00020"></a><span class="lineno">   20</span>&#160;<span class="preprocessor">#include &lt;vector&gt;</span></div><div class="line"><a name="l00021"></a><span class="lineno">   21</span>&#160;</div><div class="line"><a name="l00022"></a><span class="lineno">   22</span>&#160;</div><div class="line"><a name="l00023"></a><span class="lineno">   23</span>&#160;</div><div class="line"><a name="l00024"></a><span class="lineno">   24</span>&#160;</div><div class="line"><a name="l00025"></a><span class="lineno">   25</span>&#160;<span class="keyword">namespace </span>boost { <span class="keyword">namespace </span>gil {</div><div class="line"><a name="l00026"></a><span class="lineno">   26</span>&#160;</div><div class="line"><a name="l00027"></a><span class="lineno">   27</span>&#160;<span class="keyword">template</span> &lt;<span class="keyword">typename</span> SrcView, <span class="keyword">typename</span> DstView&gt;</div><div class="line"><a name="l00028"></a><span class="lineno">   28</span>&#160;<span class="keywordtype">void</span> box_filter(</div><div class="line"><a name="l00029"></a><span class="lineno">   29</span>&#160;    SrcView <span class="keyword">const</span>&amp; src_view,</div><div class="line"><a name="l00030"></a><span class="lineno">   30</span>&#160;    DstView <span class="keyword">const</span>&amp; dst_view,</div><div class="line"><a name="l00031"></a><span class="lineno">   31</span>&#160;    std::size_t kernel_size,</div><div class="line"><a name="l00032"></a><span class="lineno">   32</span>&#160;    <span class="keywordtype">long</span> <span class="keywordtype">int</span> anchor = -1,</div><div class="line"><a name="l00033"></a><span class="lineno">   33</span>&#160;    <span class="keywordtype">bool</span> normalize=<span class="keyword">true</span>,</div><div class="line"><a name="l00034"></a><span class="lineno">   34</span>&#160;    boundary_option option = boundary_option::extend_zero</div><div class="line"><a name="l00035"></a><span class="lineno">   35</span>&#160;)</div><div class="line"><a name="l00036"></a><span class="lineno">   36</span>&#160;{</div><div class="line"><a name="l00037"></a><span class="lineno">   37</span>&#160;    gil_function_requires&lt;ImageViewConcept&lt;SrcView&gt;&gt;();</div><div class="line"><a name="l00038"></a><span class="lineno">   38</span>&#160;    gil_function_requires&lt;MutableImageViewConcept&lt;DstView&gt;&gt;();</div><div class="line"><a name="l00039"></a><span class="lineno">   39</span>&#160;    static_assert(color_spaces_are_compatible</div><div class="line"><a name="l00040"></a><span class="lineno">   40</span>&#160;    &lt;</div><div class="line"><a name="l00041"></a><span class="lineno">   41</span>&#160;        <span class="keyword">typename</span> color_space_type&lt;SrcView&gt;::type,</div><div class="line"><a name="l00042"></a><span class="lineno">   42</span>&#160;        <span class="keyword">typename</span> color_space_type&lt;DstView&gt;::type</div><div class="line"><a name="l00043"></a><span class="lineno">   43</span>&#160;    &gt;::value, <span class="stringliteral">&quot;Source and destination views must have pixels with the same color space&quot;</span>);</div><div class="line"><a name="l00044"></a><span class="lineno">   44</span>&#160;</div><div class="line"><a name="l00045"></a><span class="lineno">   45</span>&#160;    std::vector&lt;float&gt; kernel_values;</div><div class="line"><a name="l00046"></a><span class="lineno">   46</span>&#160;    <span class="keywordflow">if</span> (normalize) { kernel_values.resize(kernel_size, 1.0f / <span class="keywordtype">float</span>(kernel_size)); }</div><div class="line"><a name="l00047"></a><span class="lineno">   47</span>&#160;    <span class="keywordflow">else</span> { kernel_values.resize(kernel_size, 1.0f); }</div><div class="line"><a name="l00048"></a><span class="lineno">   48</span>&#160;</div><div class="line"><a name="l00049"></a><span class="lineno">   49</span>&#160;    <span class="keywordflow">if</span> (anchor == -1) anchor = static_cast&lt;int&gt;(kernel_size / 2);</div><div class="line"><a name="l00050"></a><span class="lineno">   50</span>&#160;    kernel_1d&lt;float&gt; kernel(kernel_values.begin(), kernel_size, anchor);</div><div class="line"><a name="l00051"></a><span class="lineno">   51</span>&#160;</div><div class="line"><a name="l00052"></a><span class="lineno">   52</span>&#160;    detail::convolve_1d</div><div class="line"><a name="l00053"></a><span class="lineno">   53</span>&#160;    &lt;</div><div class="line"><a name="l00054"></a><span class="lineno">   54</span>&#160;        pixel&lt;float, typename SrcView::value_type::layout_t&gt;</div><div class="line"><a name="l00055"></a><span class="lineno">   55</span>&#160;    &gt;(src_view, kernel, dst_view, option);</div><div class="line"><a name="l00056"></a><span class="lineno">   56</span>&#160;}</div><div class="line"><a name="l00057"></a><span class="lineno">   57</span>&#160;</div><div class="line"><a name="l00058"></a><span class="lineno">   58</span>&#160;<span class="keyword">template</span> &lt;<span class="keyword">typename</span> SrcView, <span class="keyword">typename</span> DstView&gt;</div><div class="line"><a name="l00059"></a><span class="lineno">   59</span>&#160;<span class="keywordtype">void</span> blur(</div><div class="line"><a name="l00060"></a><span class="lineno">   60</span>&#160;    SrcView <span class="keyword">const</span>&amp; src_view,</div><div class="line"><a name="l00061"></a><span class="lineno">   61</span>&#160;    DstView <span class="keyword">const</span>&amp; dst_view,</div><div class="line"><a name="l00062"></a><span class="lineno">   62</span>&#160;    std::size_t kernel_size,</div><div class="line"><a name="l00063"></a><span class="lineno">   63</span>&#160;    <span class="keywordtype">long</span> <span class="keywordtype">int</span> anchor = -1,</div><div class="line"><a name="l00064"></a><span class="lineno">   64</span>&#160;    boundary_option option = boundary_option::extend_zero</div><div class="line"><a name="l00065"></a><span class="lineno">   65</span>&#160;)</div><div class="line"><a name="l00066"></a><span class="lineno">   66</span>&#160;{</div><div class="line"><a name="l00067"></a><span class="lineno">   67</span>&#160;    box_filter(src_view, dst_view, kernel_size, anchor, <span class="keyword">true</span>, option);</div><div class="line"><a name="l00068"></a><span class="lineno">   68</span>&#160;}</div><div class="line"><a name="l00069"></a><span class="lineno">   69</span>&#160;</div><div class="line"><a name="l00070"></a><span class="lineno">   70</span>&#160;</div><div class="line"><a name="l00071"></a><span class="lineno">   71</span>&#160;<span class="keyword">namespace </span>detail</div><div class="line"><a name="l00072"></a><span class="lineno">   72</span>&#160;{</div><div class="line"><a name="l00073"></a><span class="lineno">   73</span>&#160;<span class="keyword">template</span> &lt;<span class="keyword">typename</span> SrcView, <span class="keyword">typename</span> DstView&gt;</div><div class="line"><a name="l00074"></a><span class="lineno">   74</span>&#160;<span class="keywordtype">void</span> filter_median_impl(SrcView <span class="keyword">const</span>&amp; src_view, DstView <span class="keyword">const</span>&amp; dst_view, std::size_t kernel_size)</div><div class="line"><a name="l00075"></a><span class="lineno">   75</span>&#160;{</div><div class="line"><a name="l00076"></a><span class="lineno">   76</span>&#160;    std::size_t half_kernel_size = kernel_size / 2;</div><div class="line"><a name="l00077"></a><span class="lineno">   77</span>&#160;</div><div class="line"><a name="l00078"></a><span class="lineno">   78</span>&#160;    <span class="comment">// deciding output channel type and creating functor</span></div><div class="line"><a name="l00079"></a><span class="lineno">   79</span>&#160;    <span class="keyword">using</span> src_channel_t = <span class="keyword">typename</span> channel_type&lt;SrcView&gt;::type;</div><div class="line"><a name="l00080"></a><span class="lineno">   80</span>&#160;</div><div class="line"><a name="l00081"></a><span class="lineno">   81</span>&#160;    std::vector&lt;src_channel_t&gt; values;</div><div class="line"><a name="l00082"></a><span class="lineno">   82</span>&#160;    values.reserve(kernel_size * kernel_size);</div><div class="line"><a name="l00083"></a><span class="lineno">   83</span>&#160;</div><div class="line"><a name="l00084"></a><span class="lineno">   84</span>&#160;    <span class="keywordflow">for</span> (std::ptrdiff_t y = 0; y &lt; src_view.height(); y++)</div><div class="line"><a name="l00085"></a><span class="lineno">   85</span>&#160;    {</div><div class="line"><a name="l00086"></a><span class="lineno">   86</span>&#160;        <span class="keyword">typename</span> DstView::x_iterator dst_it = dst_view.row_begin(y);</div><div class="line"><a name="l00087"></a><span class="lineno">   87</span>&#160;</div><div class="line"><a name="l00088"></a><span class="lineno">   88</span>&#160;        <span class="keywordflow">for</span> (std::ptrdiff_t x = 0; x &lt; src_view.width(); x++)</div><div class="line"><a name="l00089"></a><span class="lineno">   89</span>&#160;        {</div><div class="line"><a name="l00090"></a><span class="lineno">   90</span>&#160;            <span class="keyword">auto</span> sub_view = subimage_view(</div><div class="line"><a name="l00091"></a><span class="lineno">   91</span>&#160;                src_view,</div><div class="line"><a name="l00092"></a><span class="lineno">   92</span>&#160;                x - half_kernel_size, y - half_kernel_size,</div><div class="line"><a name="l00093"></a><span class="lineno">   93</span>&#160;                kernel_size,</div><div class="line"><a name="l00094"></a><span class="lineno">   94</span>&#160;                kernel_size</div><div class="line"><a name="l00095"></a><span class="lineno">   95</span>&#160;            );</div><div class="line"><a name="l00096"></a><span class="lineno">   96</span>&#160;            values.assign(sub_view.begin(), sub_view.end());</div><div class="line"><a name="l00097"></a><span class="lineno">   97</span>&#160;</div><div class="line"><a name="l00098"></a><span class="lineno">   98</span>&#160;            std::nth_element(values.begin(), values.begin() + (values.size() / 2), values.end());</div><div class="line"><a name="l00099"></a><span class="lineno">   99</span>&#160;            dst_it[x] = values[values.size() / 2];</div><div class="line"><a name="l00100"></a><span class="lineno">  100</span>&#160;        }</div><div class="line"><a name="l00101"></a><span class="lineno">  101</span>&#160;    }</div><div class="line"><a name="l00102"></a><span class="lineno">  102</span>&#160;}</div><div class="line"><a name="l00103"></a><span class="lineno">  103</span>&#160;} <span class="comment">// namespace detail</span></div><div class="line"><a name="l00104"></a><span class="lineno">  104</span>&#160;</div><div class="line"><a name="l00105"></a><span class="lineno">  105</span>&#160;<span class="keyword">template</span> &lt;<span class="keyword">typename</span> SrcView, <span class="keyword">typename</span> DstView&gt;</div><div class="line"><a name="l00106"></a><span class="lineno">  106</span>&#160;<span class="keywordtype">void</span> median_filter(SrcView <span class="keyword">const</span>&amp; src_view, DstView <span class="keyword">const</span>&amp; dst_view, std::size_t kernel_size)</div><div class="line"><a name="l00107"></a><span class="lineno">  107</span>&#160;{</div><div class="line"><a name="l00108"></a><span class="lineno">  108</span>&#160;    static_assert(color_spaces_are_compatible</div><div class="line"><a name="l00109"></a><span class="lineno">  109</span>&#160;    &lt;</div><div class="line"><a name="l00110"></a><span class="lineno">  110</span>&#160;        <span class="keyword">typename</span> color_space_type&lt;SrcView&gt;::type,</div><div class="line"><a name="l00111"></a><span class="lineno">  111</span>&#160;        <span class="keyword">typename</span> color_space_type&lt;DstView&gt;::type</div><div class="line"><a name="l00112"></a><span class="lineno">  112</span>&#160;    &gt;::value, <span class="stringliteral">&quot;Source and destination views must have pixels with the same color space&quot;</span>);</div><div class="line"><a name="l00113"></a><span class="lineno">  113</span>&#160;</div><div class="line"><a name="l00114"></a><span class="lineno">  114</span>&#160;    std::size_t half_kernel_size = kernel_size / 2;</div><div class="line"><a name="l00115"></a><span class="lineno">  115</span>&#160;    <span class="keyword">auto</span> extended_img = extend_boundary(</div><div class="line"><a name="l00116"></a><span class="lineno">  116</span>&#160;        src_view,</div><div class="line"><a name="l00117"></a><span class="lineno">  117</span>&#160;        half_kernel_size,</div><div class="line"><a name="l00118"></a><span class="lineno">  118</span>&#160;        boundary_option::extend_constant</div><div class="line"><a name="l00119"></a><span class="lineno">  119</span>&#160;    );</div><div class="line"><a name="l00120"></a><span class="lineno">  120</span>&#160;    <span class="keyword">auto</span> extended_view = subimage_view(</div><div class="line"><a name="l00121"></a><span class="lineno">  121</span>&#160;            <a class="code" href="group___image_model.html#ga633557dbbff2d21c784b73412b47bb38">view</a>(extended_img),</div><div class="line"><a name="l00122"></a><span class="lineno">  122</span>&#160;            half_kernel_size,</div><div class="line"><a name="l00123"></a><span class="lineno">  123</span>&#160;            half_kernel_size,</div><div class="line"><a name="l00124"></a><span class="lineno">  124</span>&#160;            src_view.width(),</div><div class="line"><a name="l00125"></a><span class="lineno">  125</span>&#160;            src_view.height()</div><div class="line"><a name="l00126"></a><span class="lineno">  126</span>&#160;        );</div><div class="line"><a name="l00127"></a><span class="lineno">  127</span>&#160;</div><div class="line"><a name="l00128"></a><span class="lineno">  128</span>&#160;    <span class="keywordflow">for</span> (std::size_t channel = 0; channel &lt; extended_view.num_channels(); channel++)</div><div class="line"><a name="l00129"></a><span class="lineno">  129</span>&#160;    {</div><div class="line"><a name="l00130"></a><span class="lineno">  130</span>&#160;        detail::filter_median_impl(</div><div class="line"><a name="l00131"></a><span class="lineno">  131</span>&#160;            nth_channel_view(extended_view, channel),</div><div class="line"><a name="l00132"></a><span class="lineno">  132</span>&#160;            nth_channel_view(dst_view, channel),</div><div class="line"><a name="l00133"></a><span class="lineno">  133</span>&#160;            kernel_size</div><div class="line"><a name="l00134"></a><span class="lineno">  134</span>&#160;        );</div><div class="line"><a name="l00135"></a><span class="lineno">  135</span>&#160;    }</div><div class="line"><a name="l00136"></a><span class="lineno">  136</span>&#160;}</div><div class="line"><a name="l00137"></a><span class="lineno">  137</span>&#160;</div><div class="line"><a name="l00138"></a><span class="lineno">  138</span>&#160;}} <span class="comment">//namespace boost::gil</span></div><div class="line"><a name="l00139"></a><span class="lineno">  139</span>&#160;</div><div class="line"><a name="l00140"></a><span class="lineno">  140</span>&#160;<span class="preprocessor">#endif // !BOOST_GIL_IMAGE_PROCESSING_FILTER_HPP</span></div><div class="ttc" id="group___image_model_html_ga633557dbbff2d21c784b73412b47bb38"><div class="ttname"><a href="group___image_model.html#ga633557dbbff2d21c784b73412b47bb38">boost::gil::view</a></div><div class="ttdeci">const image&lt; Pixel, IsPlanar, Alloc &gt;::view_t &amp; view(image&lt; Pixel, IsPlanar, Alloc &gt; &amp;img)</div><div class="ttdoc">Returns the non-constant-pixel view of an image.</div><div class="ttdef"><b>Definition:</b> image.hpp:443</div></div>
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