<div dir="ltr"><div>Dear Mat,</div><div><br></div><div>not sure if this helps,</div><div>but here is a way, how to set brightness using a constant value.</div><div><br></div><div>I guess for automatization one can figure out a way using mean pixel value.</div><div><br></div><div>Best Regards,</div><div>Philipp<br></div><div><br></div><div><pre style="font-family:Monospaced;font-style:normal"><span style="color:rgb(0,0,0)">img</span> <span style="color:rgb(92,92,92)">=</span> <span style="color:rgb(174,92,176);text-decoration:underline">imread</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(50,185,185)">fullpath</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(174,92,176);text-decoration:underline">getIPCVpath</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(74,85,219)">)</span> <span style="color:rgb(92,92,92)">+</span> <span style="color:rgb(188,143,143)">"</span><span style="color:rgb(188,143,143)">/images/</span><span style="color:rgb(188,143,143)">"</span> <span style="color:rgb(92,92,92)">+</span> <span style="color:rgb(188,143,143)">'</span><span style="color:rgb(188,143,143)">baboon.png</span><span style="color:rgb(188,143,143)">'</span><span style="color:rgb(74,85,219)">)</span><span style="color:rgb(74,85,219)">)</span><span style="color:rgb(0,0,0)">;</span>

 <span style="color:rgb(100,174,100);font-style:italic">// image size = 512 x 512</span>

<span style="color:rgb(100,174,100);font-style:italic">// result of </span><span style="color:rgb(100,174,100);font-style:italic">"</span><span style="color:rgb(100,174,100);font-style:italic">imread</span><span style="color:rgb(100,174,100);font-style:italic">"</span><span style="color:rgb(100,174,100);font-style:italic"> is of type 10 --</span><span style="color:rgb(100,174,100);font-style:italic">></span><span style="color:rgb(100,174,100);font-style:italic"> text object</span>
<span style="color:rgb(100,174,100);font-style:italic">// (???)..guess: type = unsigned char, which is 8 bit</span>
<span style="color:rgb(100,174,100);font-style:italic">//</span>
<span style="color:rgb(100,174,100);font-style:italic">// However this limits the pixel values between 0 and 255</span>
<span style="color:rgb(100,174,100);font-style:italic">// e.g.: 255 + 1 will be set to </span><span style="color:rgb(100,174,100);font-style:italic">"</span><span style="color:rgb(100,174,100);font-style:italic">0</span><span style="color:rgb(100,174,100);font-style:italic">"</span>
<span style="color:rgb(100,174,100);font-style:italic">//</span>
<span style="color:rgb(100,174,100);font-style:italic">// for brightness control we must be able to exceed 255.</span>
<span style="color:rgb(100,174,100);font-style:italic">// ..we also want to go into negative pixel values</span>
<span style="color:rgb(100,174,100);font-style:italic">// so we need to change integer type...use int16</span>
<span style="color:rgb(100,174,100);font-style:italic">// positive pixel values above 255 will be set to 255 afterwards</span>
<span style="color:rgb(100,174,100);font-style:italic">// negative pixel values will be set to 0 afterwards</span>

<span style="color:rgb(0,0,0)">nPx</span> <span style="color:rgb(92,92,92)">=</span> <span style="color:rgb(188,143,143)">512</span><span style="color:rgb(92,92,92)">*</span><span style="color:rgb(188,143,143)">512</span><span style="color:rgb(0,0,0)">;</span>

<span style="color:rgb(0,0,0)">brighnessLv_1</span> <span style="color:rgb(92,92,92)">=</span> <span style="color:rgb(188,143,143)">128</span><span style="color:rgb(0,0,0)">;</span>
<span style="color:rgb(0,0,0)">brighnessLv_2</span> <span style="color:rgb(92,92,92)">=</span> <span style="color:rgb(92,92,92)">-</span><span style="color:rgb(188,143,143)">128</span><span style="color:rgb(0,0,0)">;</span>

<span style="color:rgb(0,0,0)">img_1</span> <span style="color:rgb(92,92,92)">=</span> <span style="color:rgb(50,185,185)">int16</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(0,0,0)">img</span><span style="color:rgb(74,85,219)">)</span><span style="color:rgb(0,0,0)">;</span> 
<span style="color:rgb(0,0,0)">img_1</span> <span style="color:rgb(92,92,92)">=</span> <span style="color:rgb(0,0,0)">img_1</span> <span style="color:rgb(92,92,92)">+</span> <span style="color:rgb(0,0,0)">brighnessLv_1</span><span style="color:rgb(0,0,0)">;</span>
   
<span style="color:rgb(0,0,0)">img_2</span> <span style="color:rgb(92,92,92)">=</span> <span style="color:rgb(50,185,185)">int16</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(0,0,0)">img</span><span style="color:rgb(74,85,219)">)</span><span style="color:rgb(0,0,0)">;</span>
<span style="color:rgb(0,0,0)">img_2</span> <span style="color:rgb(92,92,92)">=</span> <span style="color:rgb(0,0,0)">img_2</span> <span style="color:rgb(92,92,92)">+</span> <span style="color:rgb(0,0,0)">brighnessLv_2</span><span style="color:rgb(0,0,0)">;</span>

<span style="color:rgb(0,0,0)">pos</span> <span style="color:rgb(92,92,92)">=</span> <span style="color:rgb(50,185,185)">find</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(0,0,0)">img_1</span> <span style="color:rgb(92,92,92)">></span> <span style="color:rgb(188,143,143)">255</span><span style="color:rgb(74,85,219)">)</span><span style="color:rgb(0,0,0)">;</span>
<span style="color:rgb(0,0,0)">img_1</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(0,0,0)">pos</span><span style="color:rgb(74,85,219)">)</span> <span style="color:rgb(92,92,92)">=</span> <span style="color:rgb(188,143,143)">255</span><span style="color:rgb(0,0,0)">;</span>
<span style="color:rgb(0,0,0)">pos</span> <span style="color:rgb(92,92,92)">=</span> <span style="color:rgb(50,185,185)">find</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(0,0,0)">img_1</span> <span style="color:rgb(92,92,92)"><</span> <span style="color:rgb(188,143,143)">0</span><span style="color:rgb(74,85,219)">)</span><span style="color:rgb(0,0,0)">;</span>
<span style="color:rgb(0,0,0)">img_1</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(0,0,0)">pos</span><span style="color:rgb(74,85,219)">)</span> <span style="color:rgb(92,92,92)">=</span> <span style="color:rgb(188,143,143)">0</span><span style="color:rgb(0,0,0)">;</span>

<span style="color:rgb(0,0,0)">pos</span> <span style="color:rgb(92,92,92)">=</span> <span style="color:rgb(50,185,185)">find</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(0,0,0)">img_2</span> <span style="color:rgb(92,92,92)">></span> <span style="color:rgb(188,143,143)">255</span><span style="color:rgb(74,85,219)">)</span><span style="color:rgb(0,0,0)">;</span>
<span style="color:rgb(0,0,0)">img_2</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(0,0,0)">pos</span><span style="color:rgb(74,85,219)">)</span> <span style="color:rgb(92,92,92)">=</span> <span style="color:rgb(188,143,143)">255</span><span style="color:rgb(0,0,0)">;</span>
<span style="color:rgb(0,0,0)">pos</span> <span style="color:rgb(92,92,92)">=</span> <span style="color:rgb(50,185,185)">find</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(0,0,0)">img_2</span> <span style="color:rgb(92,92,92)"><</span> <span style="color:rgb(188,143,143)">0</span><span style="color:rgb(74,85,219)">)</span><span style="color:rgb(0,0,0)">;</span>
<span style="color:rgb(0,0,0)">img_2</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(0,0,0)">pos</span><span style="color:rgb(74,85,219)">)</span> <span style="color:rgb(92,92,92)">=</span> <span style="color:rgb(188,143,143)">0</span><span style="color:rgb(0,0,0)">;</span>

<span style="color:rgb(0,0,0)">img_1</span> <span style="color:rgb(92,92,92)">=</span> <span style="color:rgb(50,185,185)">uint8</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(0,0,0)">img_1</span><span style="color:rgb(74,85,219)">)</span><span style="color:rgb(0,0,0)">;</span>
<span style="color:rgb(0,0,0)">img_2</span> <span style="color:rgb(92,92,92)">=</span> <span style="color:rgb(50,185,185)">uint8</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(0,0,0)">img_2</span><span style="color:rgb(74,85,219)">)</span><span style="color:rgb(0,0,0)">;</span>

<span style="color:rgb(0,0,0)">f</span> <span style="color:rgb(92,92,92)">=</span> <span style="color:rgb(50,185,185)">figure</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(74,85,219)">)</span><span style="color:rgb(0,0,0)">;</span>
<span style="color:rgb(0,0,0)">f</span><span style="color:rgb(92,92,92)">.</span><span style="color:rgb(170,170,170)">figure_size</span> <span style="color:rgb(92,92,92)">=</span> <span style="color:rgb(74,85,219)">[</span><span style="color:rgb(188,143,143)">1591</span><span style="color:rgb(0,0,0)">,</span><span style="color:rgb(188,143,143)">610</span><span style="color:rgb(74,85,219)">]</span><span style="color:rgb(0,0,0)">;</span>
<span style="color:rgb(0,0,0)">f</span><span style="color:rgb(92,92,92)">.</span><span style="color:rgb(170,170,170)">background</span> <span style="color:rgb(92,92,92)">=</span> <span style="color:rgb(188,143,143)">8</span><span style="color:rgb(0,0,0)">;</span>
<span style="color:rgb(174,92,176);text-decoration:underline">subplot</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(188,143,143)">1</span><span style="color:rgb(0,0,0)">,</span><span style="color:rgb(188,143,143)">3</span><span style="color:rgb(0,0,0)">,</span><span style="color:rgb(188,143,143)">1</span><span style="color:rgb(74,85,219)">)</span><span style="color:rgb(0,0,0)">;</span>
<span style="color:rgb(174,92,176);text-decoration:underline">imshow</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(0,0,0)">img</span><span style="color:rgb(74,85,219)">)</span><span style="color:rgb(0,0,0)">;</span>

<span style="color:rgb(174,92,176);text-decoration:underline">subplot</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(188,143,143)">1</span><span style="color:rgb(0,0,0)">,</span><span style="color:rgb(188,143,143)">3</span><span style="color:rgb(0,0,0)">,</span><span style="color:rgb(188,143,143)">2</span><span style="color:rgb(74,85,219)">)</span><span style="color:rgb(0,0,0)">;</span>
<span style="color:rgb(174,92,176);text-decoration:underline">imshow</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(0,0,0)">img_1</span><span style="color:rgb(74,85,219)">)</span><span style="color:rgb(0,0,0)">;</span>

<span style="color:rgb(174,92,176);text-decoration:underline">subplot</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(188,143,143)">1</span><span style="color:rgb(0,0,0)">,</span><span style="color:rgb(188,143,143)">3</span><span style="color:rgb(0,0,0)">,</span><span style="color:rgb(188,143,143)">3</span><span style="color:rgb(74,85,219)">)</span><span style="color:rgb(0,0,0)">;</span>
<span style="color:rgb(174,92,176);text-decoration:underline">imshow</span><span style="color:rgb(74,85,219)">(</span><span style="color:rgb(0,0,0)">img_2</span><span style="color:rgb(74,85,219)">)</span><span style="color:rgb(0,0,0)">;</span></pre></div><div><br></div><div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Am Di., 9. Juni 2020 um 22:05 Uhr schrieb mat368 <<a href="mailto:matthieu.gazon@orange.fr" target="_blank">matthieu.gazon@orange.fr</a>>:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Hello<br>
I am looking for a function or a code to auto adjust level of color image ?<br>
I dont see that in thé ipcv package.<br>
<br>
Thanks for tour trop.<br>
Mat<br>
<br>
<br>
<br>
--<br>
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