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<div class="refentry" title="imagegetpixel">
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<h2>
<span class="refentrytitle">imagegetpixel</span>
</h2>
<p>imagegetpixel —
Return the RGB pixel values of a previously opened or created image.
</p>
</div>
<div class="refsect1" title="Description">
<a id="idp26661048"></a>
<h2>Description</h2>
<p>Return the RGB pixel values of a previously opened or created image. An image can be loaded with <a class="link" href="imageload.html" title="imageload"><em class="citetitle">imageload</em></a>. An empty image can be created with <a class="link" href="imagecreate.html" title="imagecreate"><em class="citetitle">imagecreate</em></a>.
</p>
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<div class="refsect1" title="Syntax">
<a id="idp26690136"></a>
<h2>Syntax</h2>
<pre class="synopsis">ared, agreen, ablue <span class="command"><strong>imagegetpixel</strong></span> iimagenum, ax, ay</pre>
<pre class="synopsis">kred, kgreen, kblue <span class="command"><strong>imagegetpixel</strong></span> iimagenum, kx, ky</pre>
</div>
<div class="refsect1" title="Initialization">
<a id="idp26692040"></a>
<h2>Initialization</h2>
<p>
<span class="emphasis"><em>iimagenum</em></span> -- the reference of the image.. It should be a value returned by <a class="link" href="imageload.html" title="imageload"><em class="citetitle">imageload</em></a> or <a class="link" href="imagecreate.html" title="imagecreate"><em class="citetitle">imagecreate</em></a>.
</p>
</div>
<div class="refsect1" title="Performance">
<a id="idp26693904"></a>
<h2>Performance</h2>
<p>
<span class="emphasis"><em>ax (kx)</em></span> -- horizontal pixel position (must be a float from 0 to 1).
</p>
<p>
<span class="emphasis"><em>ay (ky)</em></span> -- vertical pixel position (must be a float from 0 to 1).
</p>
<p>
<span class="emphasis"><em>ared (kred)</em></span> -- red value of the pixel (mapped to a float from 0 to 1).
</p>
<p>
<span class="emphasis"><em>agreen (kgreen)</em></span> -- green value of the pixel (mapped to a float from 0 to 1).
</p>
<p>
<span class="emphasis"><em>ablue (kblue)</em></span> -- blue value of the pixel (mapped to a float from 0 to 1).
</p>
</div>
<div class="refsect1" title="Examples">
<a id="idp26697024"></a>
<h2>Examples</h2>
<p>
Here is an example of the imagegetpixel opcode. It uses the files <a class="ulink" href="examples/imageopcodesdemo2.csd" target="_top"><em class="citetitle">imageopcodesdemo2.csd</em></a> <a class="ulink" href="examples/test1.png" target="_top"><em class="citetitle">test1.png</em></a> and <a class="ulink" href="examples/test2.png" target="_top"><em class="citetitle">test2.png</em></a>.
</p>
<div class="example">
<a id="idp26698888"></a>
<p class="title">
<strong>Example 357. Example of the imagegetpixel opcode.</strong>
</p>
<div class="example-contents">
<pre class="programlisting">
<span class="csdtag"><CsoundSynthesizer></span>
<span class="csdtag"><CsOptions></span>
<span class="comment">; Select audio/midi flags here according to platform</span>
<span class="comment">; Audio out Audio in</span>
-odac -iadc <span class="comment">;;;RT audio I/O</span>
<span class="comment">; For Non-realtime ouput leave only the line below:</span>
<span class="comment">; -o imageopcodesdemo2.wav -W ;;; for file output any platform</span>
<span class="csdtag"></CsOptions></span>
<span class="csdtag"><CsInstruments></span>
<span class="ohdr">sr</span> <span class="op">=</span> 48000
<span class="ohdr">ksmps</span> <span class="op">=</span> 100
<span class="ohdr">nchnls</span> <span class="op">=</span> 2
<span class="comment">;By Cesare Marilungo 2008</span>
<span class="opc">zakinit</span> 10,1
<span class="comment">;Load the image - should be 512x512 pixels</span>
giimage <span class="opc">imageload</span> "test1.png"
<span class="comment">;giimage imageload "test2.png" ;--try this too</span>
giimagew, giimageh <span class="opc">imagesize</span> giimage
giwave <span class="ohdr">ftgen</span> 1, 0, 1024, 10, 1
gifrqs <span class="ohdr">ftgen</span> 2,0,512,<span class="op">-</span>5, 1,512,10
giamps <span class="ohdr">ftgen</span> 3, 0, 512, 10, 1
<span class="oblock">instr</span> 100
kindex <span class="op">=</span> 0
icnt <span class="op">=</span> giimageh
kx_ <span class="opc">linseg</span> 0, p3, 1
kenv <span class="opc">linseg</span> 0, .2, 500, p3 <span class="op">-</span> .4, 500, .2, 0
<span class="comment">; Read a column of pixels and store the red values</span>
<span class="comment">; inside the table 'giamps'</span>
<span class="olabel">loop</span><span class="op">:</span>
ky_ <span class="op">=</span> kindex<span class="op">/</span>giimageh
<span class="comment">;Get the pixel color values at kx_, ky_</span>
kred, kgreen, kblue <span class="opc">imagegetpixel</span> giimage, kx_, ky_
<span class="comment">;Write the red values inside the table 'giamps'</span>
<span class="opc">tablew</span> kred, kindex, giamps
kindex <span class="op">=</span> kindex<span class="op">+</span>1
<span class="octrl">if</span> (kindex <span class="op"><</span> icnt) <span class="octrl">kgoto</span> <span class="olabel">loop</span>
<span class="comment">; Use an oscillator bank (additive synthesis) to generate sound</span>
<span class="comment">; setting amplitudes for each partial according to the image</span>
asig <span class="opc">adsynt</span> kenv, 220, giwave, gifrqs, giamps, icnt, 2
<span class="opc">outs</span> asig, asig
<span class="oblock">endin</span>
<span class="oblock">instr</span> 101
<span class="comment">; Free memory used by the image</span>
<span class="opc">imagefree</span> giimage
<span class="oblock">endin</span>
<span class="csdtag"></CsInstruments></span>
<span class="csdtag"><CsScore></span>
<span class="stamnt">t</span> 0 60
<span class="stamnt">i</span>100 1 20
<span class="stamnt">i</span>101 21 1
<span class="stamnt">e</span>
<span class="csdtag"></CsScore></span>
<span class="csdtag"></CsoundSynthesizer></span>
</pre>
</div>
</div>
<p><br class="example-break" />
</p>
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<div class="refsect1" title="See Also">
<a id="idp26699920"></a>
<h2>See Also</h2>
<p>
<a class="link" href="imageload.html" title="imageload"><em class="citetitle">imageload</em></a>,
<a class="link" href="imagecreate.html" title="imagecreate"><em class="citetitle">imagecreate</em></a>,
<a class="link" href="imagesize.html" title="imagesize"><em class="citetitle">imagesize</em></a>,
<a class="link" href="imagesave.html" title="imagesave"><em class="citetitle">imagesave</em></a>,
<a class="link" href="imagesetpixel.html" title="imagesetpixel"><em class="citetitle">imagesetpixel</em></a>,
<a class="link" href="imagefree.html" title="imagefree"><em class="citetitle">imagefree</em></a>
</p>
</div>
<div class="refsect1" title="Credits">
<a id="idp26703416"></a>
<h2>Credits</h2>
<p>
</p>
<table border="0" summary="Simple list" class="simplelist">
<tr>
<td>Author: Cesare Marilungo</td>
</tr>
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<p>
</p>
<p>New in version 5.08</p>
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