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<p>Hello gmsh team,</p>
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<p>I was thinking of elegant way to mesh an binary image ( black and white). Is there simple way to define black and white regions as separate physical surfaces</p>
<p>in gmsh and automatically assign mesh size field ( finer for white , coarser for black ) ? I saw one example where one of the author of gmsh meshes his own</p>
<p>image and it is very interesting to see this but in his code, is there a way to mark different regions of color with physical marker, for example all dark regions</p>
<p>where finer mesh occurs as one physical marker based on pixel value of image ? </p>
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<p><a href="http://www.montefiore.ulg.ac.be/~geuzaine/" class="OWAAutoLink" id="LPlnk541391" previewremoved="true">http://www.montefiore.ulg.ac.be/~geuzaine/</a><br>
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<pre style="word-wrap: break-word; white-space: pre-wrap;">// Merge the image (this will create a new post-processing view,
// View[0])
Merge "cg.jpg";
// Modify the normalized pixel values to make them reasonnable
// characteristic lengths for the mesh
Plugin(ModifyComponents).Expression0 = "v0 * 10";
Plugin(ModifyComponents).Run;
// Apply the view as the current background mesh
Background Mesh View[0];
// Build a simple geometry on top of the background mesh
w = View[0].MaxX;
h = View[0].MaxY;
Point(1)={0,0,0,w};
Point(2)={w,0,0,w};
Point(3)={w,h,0,w};
Point(4)={0,h,0,w};
Line(1) = {1,2};
Line(2) = {2,3};
Line(3) = {3,4};
Line(4) = {4,1};
Line Loop(5) = {3,4,1,2};
Plane Surface(6) = {5};</pre>
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<div name="divtagdefaultwrapper" style="margin:0px"><font face="Times New Roman, Times, serif">Best Regards,</font></div>
<div name="divtagdefaultwrapper" style="margin:0px"><font face="Times New Roman, Times, serif"><br>
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<div name="divtagdefaultwrapper" style="margin:0px"><span style="font-family:"Times New Roman",Times,serif">Sathyanarayan Rao, PhD student</span></div>
<div name="divtagdefaultwrapper" style="margin:0px"><span style="font-family:"Times New Roman",Times,serif; background-color:rgb(255,255,255); white-space:pre-wrap">Earth and Life Institute/Environmental Sciences (ELI-e)</span></div>
<div name="divtagdefaultwrapper" style="margin:0px"><span style="background-color:rgb(255,255,255); font-family:"Times New Roman",Times,serif; white-space:pre-wrap">Université catholique de Louvain</span></div>
<div name="divtagdefaultwrapper" style="margin:0px"><span style="font-family:"Times New Roman",Times,serif; white-space:pre-wrap; background-color:rgb(255,255,255)">c.037, Croix du Sud 2, Louvain-la-Neuve, Belgium
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<div name="divtagdefaultwrapper" style="margin:0px"><span style="background-color:rgb(255,255,255); white-space:pre-wrap">Phone: 010473827 ( intercom 73827)</span></div>
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<pre cols="72" style="white-space:pre-wrap; background-color:rgb(255,255,255)"><hr></pre>
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