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 113
 114 <div class="header">
 115   <div class="summary">
 116 <a href="#func-members">Functions</a>  </div>
 117   <div class="headertitle">
 118 <div class="title">warp_perspective.cl File Reference</div>  </div>
 119 </div><!--header-->
 120 <div class="contents">
 121 <div class="textblock"><code>#include &quot;<a class="el" href="helpers_8h_source.xhtml">helpers.h</a>&quot;</code><br />
 122 <code>#include &quot;<a class="el" href="warp__helpers_8h_source.xhtml">warp_helpers.h</a>&quot;</code><br />
 123 </div>
 124 <p><a href="warp__perspective_8cl_source.xhtml">Go to the source code of this file.</a></p>
 125 <table class="memberdecls">
 126 <tr class="heading"><td colspan="2"><h2 class="groupheader"><a name="func-members"></a>
 127 Functions</h2></td></tr>
 128 <tr class="memitem:aa02a47b9dfa96a2705d5c77044a40048"><td class="memItemLeft" align="right" valign="top">const float16&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="warp__perspective_8cl.xhtml#aa02a47b9dfa96a2705d5c77044a40048">build_perspective_mtx</a> ()</td></tr>
 129 <tr class="memdesc:aa02a47b9dfa96a2705d5c77044a40048"><td class="mdescLeft">&#160;</td><td class="mdescRight">Returns the perspective matrix.  <a href="#aa02a47b9dfa96a2705d5c77044a40048">More...</a><br /></td></tr>
 130 <tr class="separator:aa02a47b9dfa96a2705d5c77044a40048"><td class="memSeparator" colspan="2">&#160;</td></tr>
 131 <tr class="memitem:a2791d623c1dbcf7e7111b8ff1b7daeeb"><td class="memItemLeft" align="right" valign="top">const float8&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="warp__perspective_8cl.xhtml#a2791d623c1dbcf7e7111b8ff1b7daeeb">apply_perspective_transform</a> (const float2 coord, const float16 mtx)</td></tr>
 132 <tr class="memdesc:a2791d623c1dbcf7e7111b8ff1b7daeeb"><td class="mdescLeft">&#160;</td><td class="mdescRight">Transforms four 2D coordinates using the formula:  <a href="#a2791d623c1dbcf7e7111b8ff1b7daeeb">More...</a><br /></td></tr>
 133 <tr class="separator:a2791d623c1dbcf7e7111b8ff1b7daeeb"><td class="memSeparator" colspan="2">&#160;</td></tr>
 134 <tr class="memitem:ab8f5d79d7699ec7e2a805a25ca0fca2b"><td class="memItemLeft" align="right" valign="top">__kernel void&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="warp__perspective_8cl.xhtml#ab8f5d79d7699ec7e2a805a25ca0fca2b">warp_perspective_nearest_neighbour</a> (__global uchar *in_ptr, uint in_stride_x, uint in_step_x, uint in_stride_y, uint in_step_y, uint in_offset_first_element_in_bytes, __global uchar *out_ptr, uint out_stride_x, uint out_step_x, uint out_stride_y, uint out_step_y, uint out_offset_first_element_in_bytes, const int width, const int height)</td></tr>
 135 <tr class="memdesc:ab8f5d79d7699ec7e2a805a25ca0fca2b"><td class="mdescLeft">&#160;</td><td class="mdescRight">Performs perspective transformation on an image interpolating with the NEAREAST NEIGHBOUR method.  <a href="#ab8f5d79d7699ec7e2a805a25ca0fca2b">More...</a><br /></td></tr>
 136 <tr class="separator:ab8f5d79d7699ec7e2a805a25ca0fca2b"><td class="memSeparator" colspan="2">&#160;</td></tr>
 137 <tr class="memitem:a5dba6d401b54fd02d20a2ba246668d93"><td class="memItemLeft" align="right" valign="top">__kernel void&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="warp__perspective_8cl.xhtml#a5dba6d401b54fd02d20a2ba246668d93">warp_perspective_bilinear</a> (__global uchar *in_ptr, uint in_stride_x, uint in_step_x, uint in_stride_y, uint in_step_y, uint in_offset_first_element_in_bytes, __global uchar *out_ptr, uint out_stride_x, uint out_step_x, uint out_stride_y, uint out_step_y, uint out_offset_first_element_in_bytes, const int width, const int height)</td></tr>
 138 <tr class="memdesc:a5dba6d401b54fd02d20a2ba246668d93"><td class="mdescLeft">&#160;</td><td class="mdescRight">Performs a perspective transform on an image interpolating with the BILINEAR method.  <a href="#a5dba6d401b54fd02d20a2ba246668d93">More...</a><br /></td></tr>
 139 <tr class="separator:a5dba6d401b54fd02d20a2ba246668d93"><td class="memSeparator" colspan="2">&#160;</td></tr>
 140 </table>
 141 <h2 class="groupheader">Function Documentation</h2>
 142 <a class="anchor" id="a2791d623c1dbcf7e7111b8ff1b7daeeb"></a>
 143 <div class="memitem">
 144 <div class="memproto">
 145 <table class="mlabels">
 146   <tr>
 147   <td class="mlabels-left">
 148       <table class="memname">
 149         <tr>
 150           <td class="memname">const float8 apply_perspective_transform </td>
 151           <td>(</td>
 152           <td class="paramtype">const float2&#160;</td>
 153           <td class="paramname"><em>coord</em>, </td>
 154         </tr>
 155         <tr>
 156           <td class="paramkey"></td>
 157           <td></td>
 158           <td class="paramtype">const float16&#160;</td>
 159           <td class="paramname"><em>mtx</em>&#160;</td>
 160         </tr>
 161         <tr>
 162           <td></td>
 163           <td>)</td>
 164           <td></td><td></td>
 165         </tr>
 166       </table>
 167   </td>
 168   <td class="mlabels-right">
 169 <span class="mlabels"><span class="mlabel">inline</span></span>  </td>
 170   </tr>
 171 </table>
 172 </div><div class="memdoc">
 173
 174 <p>Transforms four 2D coordinates using the formula: </p>
 175 <p>x0 = M[1][1] * x + M[1][2] * y + M[1][3] y0 = M[2][1] * x + M[2][2] * y + M[2][3] z0 = M[3][1] * x + M[3][2] * y + M[3][3]</p>
 176 <p>(x0/z0,y0/z0)</p>
 177 <dl class="params"><dt>Parameters</dt><dd>
 178   <table class="params">
 179     <tr><td class="paramdir">[in]</td><td class="paramname">coord</td><td>2D coordinate to transform. </td></tr>
 180     <tr><td class="paramdir">[in]</td><td class="paramname">mtx</td><td>perspective matrix</td></tr>
 181   </table>
 182   </dd>
 183 </dl>
 184 <dl class="section return"><dt>Returns</dt><dd>a vector float8 containing four 2D transformed values. </dd></dl>
 185
 186 <p>Definition at line <a class="el" href="warp__perspective_8cl_source.xhtml#l00046">46</a> of file <a class="el" href="warp__perspective_8cl_source.xhtml">warp_perspective.cl</a>.</p>
 187
 188 <p>Referenced by <a class="el" href="warp__perspective_8cl_source.xhtml#l00119">warp_perspective_bilinear()</a>, and <a class="el" href="warp__perspective_8cl_source.xhtml#l00087">warp_perspective_nearest_neighbour()</a>.</p>
 189 <div class="fragment"><div class="line"><a name="l00047"></a><span class="lineno">   47</span>&#160;{</div><div class="line"><a name="l00048"></a><span class="lineno">   48</span>&#160;    <span class="keyword">const</span> float4 in_x_coords = (float4)(coord.s0, 1 + coord.s0, 2 + coord.s0, 3 + coord.s0);</div><div class="line"><a name="l00049"></a><span class="lineno">   49</span>&#160;    <span class="comment">// transform [z,z+1,z+2,z+3]</span></div><div class="line"><a name="l00050"></a><span class="lineno">   50</span>&#160;    <span class="keyword">const</span> float4 z = (float4)mad(in_x_coords, (float4)(mtx.s2), mad((float4)(coord.s1), (float4)(mtx.s5), (float4)(mtx.s8)));</div><div class="line"><a name="l00051"></a><span class="lineno">   51</span>&#160;    <span class="comment">// NOTE: Do not multiply x&amp;y by 1.f/Z as this will result in loss of accuracy and mismatches with VX reference implementation</span></div><div class="line"><a name="l00052"></a><span class="lineno">   52</span>&#160;    <span class="comment">// transform [x,x+1,x+2,x+3]</span></div><div class="line"><a name="l00053"></a><span class="lineno">   53</span>&#160;    <span class="keyword">const</span> float4 new_x = (float4)mad(in_x_coords, (float4)(mtx.s0), mad((float4)(coord.s1), (float4)(mtx.s3), (float4)(mtx.s6))) / z;</div><div class="line"><a name="l00054"></a><span class="lineno">   54</span>&#160;    <span class="comment">// transform [y,y+1,y+2,y+3]</span></div><div class="line"><a name="l00055"></a><span class="lineno">   55</span>&#160;    <span class="keyword">const</span> float4 new_y = (float4)mad(in_x_coords, (float4)(mtx.s1), mad((float4)(coord.s1), (float4)(mtx.s4), (float4)(mtx.s7))) / z;</div><div class="line"><a name="l00056"></a><span class="lineno">   56</span>&#160;    <span class="keywordflow">return</span> (float8)(new_x.s0, new_y.s0, new_x.s1, new_y.s1, new_x.s2, new_y.s2, new_x.s3, new_y.s3);</div><div class="line"><a name="l00057"></a><span class="lineno">   57</span>&#160;}</div></div><!-- fragment -->
 190 </div>
 191 </div>
 192 <a class="anchor" id="aa02a47b9dfa96a2705d5c77044a40048"></a>
 193 <div class="memitem">
 194 <div class="memproto">
 195 <table class="mlabels">
 196   <tr>
 197   <td class="mlabels-left">
 198       <table class="memname">
 199         <tr>
 200           <td class="memname">const float16 build_perspective_mtx </td>
 201           <td>(</td>
 202           <td class="paramname"></td><td>)</td>
 203           <td></td>
 204         </tr>
 205       </table>
 206   </td>
 207   <td class="mlabels-right">
 208 <span class="mlabels"><span class="mlabel">inline</span></span>  </td>
 209   </tr>
 210 </table>
 211 </div><div class="memdoc">
 212
 213 <p>Returns the perspective matrix. </p>
 214
 215 <p>Definition at line <a class="el" href="warp__perspective_8cl_source.xhtml#l00028">28</a> of file <a class="el" href="warp__perspective_8cl_source.xhtml">warp_perspective.cl</a>.</p>
 216
 217 <p>Referenced by <a class="el" href="warp__perspective_8cl_source.xhtml#l00119">warp_perspective_bilinear()</a>, and <a class="el" href="warp__perspective_8cl_source.xhtml#l00087">warp_perspective_nearest_neighbour()</a>.</p>
 218 <div class="fragment"><div class="line"><a name="l00029"></a><span class="lineno">   29</span>&#160;{</div><div class="line"><a name="l00030"></a><span class="lineno">   30</span>&#160;    <span class="keywordflow">return</span> (float16)(MAT0, MAT1, MAT2, MAT3, MAT4, MAT5, MAT6, MAT7, MAT8, 0, 0, 0, (float4)0);</div><div class="line"><a name="l00031"></a><span class="lineno">   31</span>&#160;}</div></div><!-- fragment -->
 219 </div>
 220 </div>
 221 <a class="anchor" id="a5dba6d401b54fd02d20a2ba246668d93"></a>
 222 <div class="memitem">
 223 <div class="memproto">
 224       <table class="memname">
 225         <tr>
 226           <td class="memname">__kernel void warp_perspective_bilinear </td>
 227           <td>(</td>
 228           <td class="paramtype">__global uchar *&#160;</td>
 229           <td class="paramname"><em>in_ptr</em>, </td>
 230         </tr>
 231         <tr>
 232           <td class="paramkey"></td>
 233           <td></td>
 234           <td class="paramtype">uint&#160;</td>
 235           <td class="paramname"><em>in_stride_x</em>, </td>
 236         </tr>
 237         <tr>
 238           <td class="paramkey"></td>
 239           <td></td>
 240           <td class="paramtype">uint&#160;</td>
 241           <td class="paramname"><em>in_step_x</em>, </td>
 242         </tr>
 243         <tr>
 244           <td class="paramkey"></td>
 245           <td></td>
 246           <td class="paramtype">uint&#160;</td>
 247           <td class="paramname"><em>in_stride_y</em>, </td>
 248         </tr>
 249         <tr>
 250           <td class="paramkey"></td>
 251           <td></td>
 252           <td class="paramtype">uint&#160;</td>
 253           <td class="paramname"><em>in_step_y</em>, </td>
 254         </tr>
 255         <tr>
 256           <td class="paramkey"></td>
 257           <td></td>
 258           <td class="paramtype">uint&#160;</td>
 259           <td class="paramname"><em>in_offset_first_element_in_bytes</em>, </td>
 260         </tr>
 261         <tr>
 262           <td class="paramkey"></td>
 263           <td></td>
 264           <td class="paramtype">__global uchar *&#160;</td>
 265           <td class="paramname"><em>out_ptr</em>, </td>
 266         </tr>
 267         <tr>
 268           <td class="paramkey"></td>
 269           <td></td>
 270           <td class="paramtype">uint&#160;</td>
 271           <td class="paramname"><em>out_stride_x</em>, </td>
 272         </tr>
 273         <tr>
 274           <td class="paramkey"></td>
 275           <td></td>
 276           <td class="paramtype">uint&#160;</td>
 277           <td class="paramname"><em>out_step_x</em>, </td>
 278         </tr>
 279         <tr>
 280           <td class="paramkey"></td>
 281           <td></td>
 282           <td class="paramtype">uint&#160;</td>
 283           <td class="paramname"><em>out_stride_y</em>, </td>
 284         </tr>
 285         <tr>
 286           <td class="paramkey"></td>
 287           <td></td>
 288           <td class="paramtype">uint&#160;</td>
 289           <td class="paramname"><em>out_step_y</em>, </td>
 290         </tr>
 291         <tr>
 292           <td class="paramkey"></td>
 293           <td></td>
 294           <td class="paramtype">uint&#160;</td>
 295           <td class="paramname"><em>out_offset_first_element_in_bytes</em>, </td>
 296         </tr>
 297         <tr>
 298           <td class="paramkey"></td>
 299           <td></td>
 300           <td class="paramtype">const int&#160;</td>
 301           <td class="paramname"><em>width</em>, </td>
 302         </tr>
 303         <tr>
 304           <td class="paramkey"></td>
 305           <td></td>
 306           <td class="paramtype">const int&#160;</td>
 307           <td class="paramname"><em>height</em>&#160;</td>
 308         </tr>
 309         <tr>
 310           <td></td>
 311           <td>)</td>
 312           <td></td><td></td>
 313         </tr>
 314       </table>
 315 </div><div class="memdoc">
 316
 317 <p>Performs a perspective transform on an image interpolating with the BILINEAR method. </p>
 318 <p>Input and output are single channel U8.</p>
 319 <dl class="section attention"><dt>Attention</dt><dd>The matrix coefficients need to be passed at compile time:<br />
 320 const char build_options [] = "-DMAT0=1 -DMAT1=2 -DMAT2=3 -DMAT3=4 -DMAT4=5 -DMAT5=6 -DMAT6=7 -DMAT7=8 -DMAT8=9"<br />
 321 clBuildProgram( program, 0, NULL, build_options, NULL, NULL);</dd></dl>
 322 <dl class="params"><dt>Parameters</dt><dd>
 323   <table class="params">
 324     <tr><td class="paramdir">[in]</td><td class="paramname">in_ptr</td><td>Pointer to the source image. Supported data types: U8. </td></tr>
 325     <tr><td class="paramdir">[in]</td><td class="paramname">in_stride_x</td><td>Stride of the source image in X dimension (in bytes) </td></tr>
 326     <tr><td class="paramdir">[in]</td><td class="paramname">in_step_x</td><td>in_stride_x * number of elements along X processed per work item (in bytes) </td></tr>
 327     <tr><td class="paramdir">[in]</td><td class="paramname">in_stride_y</td><td>Stride of the source image in Y dimension (in bytes) </td></tr>
 328     <tr><td class="paramdir">[in]</td><td class="paramname">in_step_y</td><td>in_stride_y * number of elements along Y processed per work item (in bytes) </td></tr>
 329     <tr><td class="paramdir">[in]</td><td class="paramname">in_offset_first_element_in_bytes</td><td>Offset of the first element in the source image </td></tr>
 330     <tr><td class="paramdir">[out]</td><td class="paramname">out_ptr</td><td>Pointer to the destination image. Supported data types: U8. </td></tr>
 331     <tr><td class="paramdir">[in]</td><td class="paramname">out_stride_x</td><td>Stride of the destination image in X dimension (in bytes) </td></tr>
 332     <tr><td class="paramdir">[in]</td><td class="paramname">out_step_x</td><td>out_stride_x * number of elements along X processed per work item (in bytes) </td></tr>
 333     <tr><td class="paramdir">[in]</td><td class="paramname">out_stride_y</td><td>Stride of the destination image in Y dimension (in bytes) </td></tr>
 334     <tr><td class="paramdir">[in]</td><td class="paramname">out_step_y</td><td>out_stride_y * number of elements along Y processed per work item (in bytes) </td></tr>
 335     <tr><td class="paramdir">[in]</td><td class="paramname">out_offset_first_element_in_bytes</td><td>Offset of the first element in the destination image </td></tr>
 336     <tr><td class="paramdir">[in]</td><td class="paramname">width</td><td>Width of the destination image </td></tr>
 337     <tr><td class="paramdir">[in]</td><td class="paramname">height</td><td>Height of the destination image </td></tr>
 338   </table>
 339   </dd>
 340 </dl>
 341
 342 <p>Definition at line <a class="el" href="warp__perspective_8cl_source.xhtml#l00119">119</a> of file <a class="el" href="warp__perspective_8cl_source.xhtml">warp_perspective.cl</a>.</p>
 343
 344 <p>References <a class="el" href="warp__perspective_8cl_source.xhtml#l00046">apply_perspective_transform()</a>, <a class="el" href="warp__helpers_8h_source.xhtml#l00080">bilinear_interpolate()</a>, <a class="el" href="warp__perspective_8cl_source.xhtml#l00028">build_perspective_mtx()</a>, <a class="el" href="warp__helpers_8h_source.xhtml#l00033">clamp_to_border()</a>, <a class="el" href="helpers_8h_source.xhtml#l00073">CONVERT_TO_IMAGE_STRUCT</a>, <a class="el" href="helpers_8h_source.xhtml#l00076">CONVERT_TO_IMAGE_STRUCT_NO_STEP</a>, <a class="el" href="warp__helpers_8h_source.xhtml#l00054">get_current_coords()</a>, and <a class="el" href="helpers_8h_source.xhtml#l00097">Image::ptr</a>.</p>
 345 <div class="fragment"><div class="line"><a name="l00124"></a><span class="lineno">  124</span>&#160;{</div><div class="line"><a name="l00125"></a><span class="lineno">  125</span>&#160;    <a class="code" href="struct_image.xhtml">Image</a> in  = <a class="code" href="helpers_8h.xhtml#a4334a4a76f8e9628c0fb9e1acf616e2a">CONVERT_TO_IMAGE_STRUCT_NO_STEP</a>(in);</div><div class="line"><a name="l00126"></a><span class="lineno">  126</span>&#160;    <a class="code" href="struct_image.xhtml">Image</a> out = <a class="code" href="helpers_8h.xhtml#aebe814363556c244be043b13e7969197">CONVERT_TO_IMAGE_STRUCT</a>(out);</div><div class="line"><a name="l00127"></a><span class="lineno">  127</span>&#160;    vstore4(<a class="code" href="warp__helpers_8h.xhtml#abea9f226daf3e0ad741d03cf7417d353">bilinear_interpolate</a>(&amp;in, <a class="code" href="warp__helpers_8h.xhtml#adbdf2ca9e8fe0b67f9359929ef743126">clamp_to_border</a>(<a class="code" href="warp__perspective_8cl.xhtml#a2791d623c1dbcf7e7111b8ff1b7daeeb">apply_perspective_transform</a>(<a class="code" href="warp__helpers_8h.xhtml#a4caaeeb51ea58015267a9974675226d1">get_current_coords</a>(), <a class="code" href="warp__perspective_8cl.xhtml#aa02a47b9dfa96a2705d5c77044a40048">build_perspective_mtx</a>()), width, height), width, height), 0, out.<a class="code" href="struct_image.xhtml#acf52c23cbd7424606c10a606524e3e32">ptr</a>);</div><div class="line"><a name="l00128"></a><span class="lineno">  128</span>&#160;}</div><div class="ttc" id="warp__helpers_8h_xhtml_adbdf2ca9e8fe0b67f9359929ef743126"><div class="ttname"><a href="warp__helpers_8h.xhtml#adbdf2ca9e8fe0b67f9359929ef743126">clamp_to_border</a></div><div class="ttdeci">const float8 clamp_to_border(float8 coords, const float width, const float height)</div><div class="ttdoc">Clamps the given coordinates to the borders. </div><div class="ttdef"><b>Definition:</b> <a href="warp__helpers_8h_source.xhtml#l00033">warp_helpers.h:33</a></div></div>
 346 <div class="ttc" id="helpers_8h_xhtml_a4334a4a76f8e9628c0fb9e1acf616e2a"><div class="ttname"><a href="helpers_8h.xhtml#a4334a4a76f8e9628c0fb9e1acf616e2a">CONVERT_TO_IMAGE_STRUCT_NO_STEP</a></div><div class="ttdeci">#define CONVERT_TO_IMAGE_STRUCT_NO_STEP(name)</div><div class="ttdef"><b>Definition:</b> <a href="helpers_8h_source.xhtml#l00076">helpers.h:76</a></div></div>
 347 <div class="ttc" id="warp__perspective_8cl_xhtml_a2791d623c1dbcf7e7111b8ff1b7daeeb"><div class="ttname"><a href="warp__perspective_8cl.xhtml#a2791d623c1dbcf7e7111b8ff1b7daeeb">apply_perspective_transform</a></div><div class="ttdeci">const float8 apply_perspective_transform(const float2 coord, const float16 mtx)</div><div class="ttdoc">Transforms four 2D coordinates using the formula: </div><div class="ttdef"><b>Definition:</b> <a href="warp__perspective_8cl_source.xhtml#l00046">warp_perspective.cl:46</a></div></div>
 348 <div class="ttc" id="helpers_8h_xhtml_aebe814363556c244be043b13e7969197"><div class="ttname"><a href="helpers_8h.xhtml#aebe814363556c244be043b13e7969197">CONVERT_TO_IMAGE_STRUCT</a></div><div class="ttdeci">#define CONVERT_TO_IMAGE_STRUCT(name)</div><div class="ttdef"><b>Definition:</b> <a href="helpers_8h_source.xhtml#l00073">helpers.h:73</a></div></div>
 349 <div class="ttc" id="warp__perspective_8cl_xhtml_aa02a47b9dfa96a2705d5c77044a40048"><div class="ttname"><a href="warp__perspective_8cl.xhtml#aa02a47b9dfa96a2705d5c77044a40048">build_perspective_mtx</a></div><div class="ttdeci">const float16 build_perspective_mtx()</div><div class="ttdoc">Returns the perspective matrix. </div><div class="ttdef"><b>Definition:</b> <a href="warp__perspective_8cl_source.xhtml#l00028">warp_perspective.cl:28</a></div></div>
 350 <div class="ttc" id="struct_image_xhtml"><div class="ttname"><a href="struct_image.xhtml">Image</a></div><div class="ttdoc">Structure to hold Image information. </div><div class="ttdef"><b>Definition:</b> <a href="helpers_8h_source.xhtml#l00095">helpers.h:95</a></div></div>
 351 <div class="ttc" id="struct_image_xhtml_acf52c23cbd7424606c10a606524e3e32"><div class="ttname"><a href="struct_image.xhtml#acf52c23cbd7424606c10a606524e3e32">Image::ptr</a></div><div class="ttdeci">__global uchar * ptr</div><div class="ttdoc">Pointer to the starting postion of the buffer. </div><div class="ttdef"><b>Definition:</b> <a href="helpers_8h_source.xhtml#l00097">helpers.h:97</a></div></div>
 352 <div class="ttc" id="warp__helpers_8h_xhtml_a4caaeeb51ea58015267a9974675226d1"><div class="ttname"><a href="warp__helpers_8h.xhtml#a4caaeeb51ea58015267a9974675226d1">get_current_coords</a></div><div class="ttdeci">const float2 get_current_coords()</div><div class="ttdoc">Returns the current thread coordinates. </div><div class="ttdef"><b>Definition:</b> <a href="warp__helpers_8h_source.xhtml#l00054">warp_helpers.h:54</a></div></div>
 353 <div class="ttc" id="warp__helpers_8h_xhtml_abea9f226daf3e0ad741d03cf7417d353"><div class="ttname"><a href="warp__helpers_8h.xhtml#abea9f226daf3e0ad741d03cf7417d353">bilinear_interpolate</a></div><div class="ttdeci">const DATA_TYPE4 bilinear_interpolate(const Image *in, const float8 coords, const float width, const float height)</div><div class="ttdoc">Computes the bilinear interpolation for each set of coordinates in the vector coords and returns the ...</div><div class="ttdef"><b>Definition:</b> <a href="warp__helpers_8h_source.xhtml#l00080">warp_helpers.h:80</a></div></div>
 354 </div><!-- fragment -->
 355 </div>
 356 </div>
 357 <a class="anchor" id="ab8f5d79d7699ec7e2a805a25ca0fca2b"></a>
 358 <div class="memitem">
 359 <div class="memproto">
 360       <table class="memname">
 361         <tr>
 362           <td class="memname">__kernel void warp_perspective_nearest_neighbour </td>
 363           <td>(</td>
 364           <td class="paramtype">__global uchar *&#160;</td>
 365           <td class="paramname"><em>in_ptr</em>, </td>
 366         </tr>
 367         <tr>
 368           <td class="paramkey"></td>
 369           <td></td>
 370           <td class="paramtype">uint&#160;</td>
 371           <td class="paramname"><em>in_stride_x</em>, </td>
 372         </tr>
 373         <tr>
 374           <td class="paramkey"></td>
 375           <td></td>
 376           <td class="paramtype">uint&#160;</td>
 377           <td class="paramname"><em>in_step_x</em>, </td>
 378         </tr>
 379         <tr>
 380           <td class="paramkey"></td>
 381           <td></td>
 382           <td class="paramtype">uint&#160;</td>
 383           <td class="paramname"><em>in_stride_y</em>, </td>
 384         </tr>
 385         <tr>
 386           <td class="paramkey"></td>
 387           <td></td>
 388           <td class="paramtype">uint&#160;</td>
 389           <td class="paramname"><em>in_step_y</em>, </td>
 390         </tr>
 391         <tr>
 392           <td class="paramkey"></td>
 393           <td></td>
 394           <td class="paramtype">uint&#160;</td>
 395           <td class="paramname"><em>in_offset_first_element_in_bytes</em>, </td>
 396         </tr>
 397         <tr>
 398           <td class="paramkey"></td>
 399           <td></td>
 400           <td class="paramtype">__global uchar *&#160;</td>
 401           <td class="paramname"><em>out_ptr</em>, </td>
 402         </tr>
 403         <tr>
 404           <td class="paramkey"></td>
 405           <td></td>
 406           <td class="paramtype">uint&#160;</td>
 407           <td class="paramname"><em>out_stride_x</em>, </td>
 408         </tr>
 409         <tr>
 410           <td class="paramkey"></td>
 411           <td></td>
 412           <td class="paramtype">uint&#160;</td>
 413           <td class="paramname"><em>out_step_x</em>, </td>
 414         </tr>
 415         <tr>
 416           <td class="paramkey"></td>
 417           <td></td>
 418           <td class="paramtype">uint&#160;</td>
 419           <td class="paramname"><em>out_stride_y</em>, </td>
 420         </tr>
 421         <tr>
 422           <td class="paramkey"></td>
 423           <td></td>
 424           <td class="paramtype">uint&#160;</td>
 425           <td class="paramname"><em>out_step_y</em>, </td>
 426         </tr>
 427         <tr>
 428           <td class="paramkey"></td>
 429           <td></td>
 430           <td class="paramtype">uint&#160;</td>
 431           <td class="paramname"><em>out_offset_first_element_in_bytes</em>, </td>
 432         </tr>
 433         <tr>
 434           <td class="paramkey"></td>
 435           <td></td>
 436           <td class="paramtype">const int&#160;</td>
 437           <td class="paramname"><em>width</em>, </td>
 438         </tr>
 439         <tr>
 440           <td class="paramkey"></td>
 441           <td></td>
 442           <td class="paramtype">const int&#160;</td>
 443           <td class="paramname"><em>height</em>&#160;</td>
 444         </tr>
 445         <tr>
 446           <td></td>
 447           <td>)</td>
 448           <td></td><td></td>
 449         </tr>
 450       </table>
 451 </div><div class="memdoc">
 452
 453 <p>Performs perspective transformation on an image interpolating with the NEAREAST NEIGHBOUR method. </p>
 454 <p>Input and output are single channel U8.</p>
 455 <p>This kernel performs perspective transform with a 3x3 Matrix M with this method of pixel coordinate translation: x0 = M[1][1] * x + M[1][2] * y + M[1][3] y0 = M[2][1] * x + M[2][2] * y + M[2][3] z0 = M[3][1] * x + M[3][2] * y + M[3][3]</p>
 456 <p>output(x,y) = input(x0/z0,y0/z0)</p>
 457 <dl class="section attention"><dt>Attention</dt><dd>The matrix coefficients need to be passed at compile time:<br />
 458 const char build_options [] = "-DMAT0=1 -DMAT1=2 -DMAT2=3 -DMAT3=4 -DMAT4=5 -DMAT5=6 -DMAT6=7 -DMAT7=8 -DMAT8=9"<br />
 459 clBuildProgram( program, 0, NULL, build_options, NULL, NULL);</dd></dl>
 460 <dl class="params"><dt>Parameters</dt><dd>
 461   <table class="params">
 462     <tr><td class="paramdir">[in]</td><td class="paramname">in_ptr</td><td>Pointer to the source image. Supported data types: U8. </td></tr>
 463     <tr><td class="paramdir">[in]</td><td class="paramname">in_stride_x</td><td>Stride of the source image in X dimension (in bytes) </td></tr>
 464     <tr><td class="paramdir">[in]</td><td class="paramname">in_step_x</td><td>in_stride_x * number of elements along X processed per work item (in bytes) </td></tr>
 465     <tr><td class="paramdir">[in]</td><td class="paramname">in_stride_y</td><td>Stride of the source image in Y dimension (in bytes) </td></tr>
 466     <tr><td class="paramdir">[in]</td><td class="paramname">in_step_y</td><td>in_stride_y * number of elements along Y processed per work item (in bytes) </td></tr>
 467     <tr><td class="paramdir">[in]</td><td class="paramname">in_offset_first_element_in_bytes</td><td>Offset of the first element in the source image </td></tr>
 468     <tr><td class="paramdir">[out]</td><td class="paramname">out_ptr</td><td>Pointer to the destination image. Supported data types: U8. </td></tr>
 469     <tr><td class="paramdir">[in]</td><td class="paramname">out_stride_x</td><td>Stride of the destination image in X dimension (in bytes) </td></tr>
 470     <tr><td class="paramdir">[in]</td><td class="paramname">out_step_x</td><td>out_stride_x * number of elements along X processed per work item (in bytes) </td></tr>
 471     <tr><td class="paramdir">[in]</td><td class="paramname">out_stride_y</td><td>Stride of the destination image in Y dimension (in bytes) </td></tr>
 472     <tr><td class="paramdir">[in]</td><td class="paramname">out_step_y</td><td>out_stride_y * number of elements along Y processed per work item (in bytes) </td></tr>
 473     <tr><td class="paramdir">[in]</td><td class="paramname">out_offset_first_element_in_bytes</td><td>Offset of the first element in the destination image </td></tr>
 474     <tr><td class="paramdir">[in]</td><td class="paramname">width</td><td>Width of the destination image </td></tr>
 475     <tr><td class="paramdir">[in]</td><td class="paramname">height</td><td>Height of the destination image </td></tr>
 476   </table>
 477   </dd>
 478 </dl>
 479
 480 <p>Definition at line <a class="el" href="warp__perspective_8cl_source.xhtml#l00087">87</a> of file <a class="el" href="warp__perspective_8cl_source.xhtml">warp_perspective.cl</a>.</p>
 481
 482 <p>References <a class="el" href="warp__perspective_8cl_source.xhtml#l00046">apply_perspective_transform()</a>, <a class="el" href="warp__perspective_8cl_source.xhtml#l00028">build_perspective_mtx()</a>, <a class="el" href="warp__helpers_8h_source.xhtml#l00033">clamp_to_border()</a>, <a class="el" href="helpers_8h_source.xhtml#l00073">CONVERT_TO_IMAGE_STRUCT</a>, <a class="el" href="helpers_8h_source.xhtml#l00076">CONVERT_TO_IMAGE_STRUCT_NO_STEP</a>, <a class="el" href="warp__helpers_8h_source.xhtml#l00054">get_current_coords()</a>, <a class="el" href="helpers_8h_source.xhtml#l00097">Image::ptr</a>, and <a class="el" href="warp__helpers_8h_source.xhtml#l00045">read_texels4()</a>.</p>
 483 <div class="fragment"><div class="line"><a name="l00092"></a><span class="lineno">   92</span>&#160;{</div><div class="line"><a name="l00093"></a><span class="lineno">   93</span>&#160;    <a class="code" href="struct_image.xhtml">Image</a> in  = <a class="code" href="helpers_8h.xhtml#a4334a4a76f8e9628c0fb9e1acf616e2a">CONVERT_TO_IMAGE_STRUCT_NO_STEP</a>(in);</div><div class="line"><a name="l00094"></a><span class="lineno">   94</span>&#160;    <a class="code" href="struct_image.xhtml">Image</a> out = <a class="code" href="helpers_8h.xhtml#aebe814363556c244be043b13e7969197">CONVERT_TO_IMAGE_STRUCT</a>(out);</div><div class="line"><a name="l00095"></a><span class="lineno">   95</span>&#160;    vstore4(<a class="code" href="warp__helpers_8h.xhtml#aba42442a4c991cdbb52727fa370676f1">read_texels4</a>(&amp;in, convert_int8(<a class="code" href="warp__helpers_8h.xhtml#adbdf2ca9e8fe0b67f9359929ef743126">clamp_to_border</a>(<a class="code" href="warp__perspective_8cl.xhtml#a2791d623c1dbcf7e7111b8ff1b7daeeb">apply_perspective_transform</a>(<a class="code" href="warp__helpers_8h.xhtml#a4caaeeb51ea58015267a9974675226d1">get_current_coords</a>(), <a class="code" href="warp__perspective_8cl.xhtml#aa02a47b9dfa96a2705d5c77044a40048">build_perspective_mtx</a>()), width, height))), 0, out.<a class="code" href="struct_image.xhtml#acf52c23cbd7424606c10a606524e3e32">ptr</a>);</div><div class="line"><a name="l00096"></a><span class="lineno">   96</span>&#160;}</div><div class="ttc" id="warp__helpers_8h_xhtml_adbdf2ca9e8fe0b67f9359929ef743126"><div class="ttname"><a href="warp__helpers_8h.xhtml#adbdf2ca9e8fe0b67f9359929ef743126">clamp_to_border</a></div><div class="ttdeci">const float8 clamp_to_border(float8 coords, const float width, const float height)</div><div class="ttdoc">Clamps the given coordinates to the borders. </div><div class="ttdef"><b>Definition:</b> <a href="warp__helpers_8h_source.xhtml#l00033">warp_helpers.h:33</a></div></div>
 484 <div class="ttc" id="helpers_8h_xhtml_a4334a4a76f8e9628c0fb9e1acf616e2a"><div class="ttname"><a href="helpers_8h.xhtml#a4334a4a76f8e9628c0fb9e1acf616e2a">CONVERT_TO_IMAGE_STRUCT_NO_STEP</a></div><div class="ttdeci">#define CONVERT_TO_IMAGE_STRUCT_NO_STEP(name)</div><div class="ttdef"><b>Definition:</b> <a href="helpers_8h_source.xhtml#l00076">helpers.h:76</a></div></div>
 485 <div class="ttc" id="warp__perspective_8cl_xhtml_a2791d623c1dbcf7e7111b8ff1b7daeeb"><div class="ttname"><a href="warp__perspective_8cl.xhtml#a2791d623c1dbcf7e7111b8ff1b7daeeb">apply_perspective_transform</a></div><div class="ttdeci">const float8 apply_perspective_transform(const float2 coord, const float16 mtx)</div><div class="ttdoc">Transforms four 2D coordinates using the formula: </div><div class="ttdef"><b>Definition:</b> <a href="warp__perspective_8cl_source.xhtml#l00046">warp_perspective.cl:46</a></div></div>
 486 <div class="ttc" id="helpers_8h_xhtml_aebe814363556c244be043b13e7969197"><div class="ttname"><a href="helpers_8h.xhtml#aebe814363556c244be043b13e7969197">CONVERT_TO_IMAGE_STRUCT</a></div><div class="ttdeci">#define CONVERT_TO_IMAGE_STRUCT(name)</div><div class="ttdef"><b>Definition:</b> <a href="helpers_8h_source.xhtml#l00073">helpers.h:73</a></div></div>
 487 <div class="ttc" id="warp__perspective_8cl_xhtml_aa02a47b9dfa96a2705d5c77044a40048"><div class="ttname"><a href="warp__perspective_8cl.xhtml#aa02a47b9dfa96a2705d5c77044a40048">build_perspective_mtx</a></div><div class="ttdeci">const float16 build_perspective_mtx()</div><div class="ttdoc">Returns the perspective matrix. </div><div class="ttdef"><b>Definition:</b> <a href="warp__perspective_8cl_source.xhtml#l00028">warp_perspective.cl:28</a></div></div>
 488 <div class="ttc" id="struct_image_xhtml"><div class="ttname"><a href="struct_image.xhtml">Image</a></div><div class="ttdoc">Structure to hold Image information. </div><div class="ttdef"><b>Definition:</b> <a href="helpers_8h_source.xhtml#l00095">helpers.h:95</a></div></div>
 489 <div class="ttc" id="struct_image_xhtml_acf52c23cbd7424606c10a606524e3e32"><div class="ttname"><a href="struct_image.xhtml#acf52c23cbd7424606c10a606524e3e32">Image::ptr</a></div><div class="ttdeci">__global uchar * ptr</div><div class="ttdoc">Pointer to the starting postion of the buffer. </div><div class="ttdef"><b>Definition:</b> <a href="helpers_8h_source.xhtml#l00097">helpers.h:97</a></div></div>
 490 <div class="ttc" id="warp__helpers_8h_xhtml_aba42442a4c991cdbb52727fa370676f1"><div class="ttname"><a href="warp__helpers_8h.xhtml#aba42442a4c991cdbb52727fa370676f1">read_texels4</a></div><div class="ttdeci">const DATA_TYPE4 read_texels4(const Image *in, const int8 coords)</div><div class="ttdoc">Reads four texels from the input image. </div><div class="ttdef"><b>Definition:</b> <a href="warp__helpers_8h_source.xhtml#l00045">warp_helpers.h:45</a></div></div>
 491 <div class="ttc" id="warp__helpers_8h_xhtml_a4caaeeb51ea58015267a9974675226d1"><div class="ttname"><a href="warp__helpers_8h.xhtml#a4caaeeb51ea58015267a9974675226d1">get_current_coords</a></div><div class="ttdeci">const float2 get_current_coords()</div><div class="ttdoc">Returns the current thread coordinates. </div><div class="ttdef"><b>Definition:</b> <a href="warp__helpers_8h_source.xhtml#l00054">warp_helpers.h:54</a></div></div>
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 501     <li class="footer">Generated on Wed Apr 12 2017 14:26:05 for ARM Compute Library by
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