Difference between revisions of "Border alignment artifact"

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When rotating a cube, the cube representing the rotated particle will have some areas where there is no information.   
 
When rotating a cube, the cube representing the rotated particle will have some areas where there is no information.   
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As a consequence, a rotated particle appears as showing an "edge". Most ''Dynamo'' programs rotate the volume into an sphere. However, sometimes it is necessary to keep the edges, for instance during [[Fourier compensation during averaging|fourier compensation during average]]
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See the effect here:
 
See the effect here:
<code>
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<pre>
 
u1=dynamo_rot(rand(64,64,64),[45,45,45]); % rotates creating a spherical halo
 
u1=dynamo_rot(rand(64,64,64),[45,45,45]); % rotates creating a spherical halo
 
u2=dpkgeom.rotation.sharpRot(rand(64,64,64),[45,45,45]); % rotates creating an edge
 
u2=dpkgeom.rotation.sharpRot(rand(64,64,64),[45,45,45]); % rotates creating an edge
 
figure;
 
figure;
 
subplot(1,2,1);dslices(u1);subplot(1,2,2);dslices(u2);
 
subplot(1,2,1);dslices(u1);subplot(1,2,2);dslices(u2);
</code>
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</pre>
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[[File:RotationArtifact.png|thumb|center|800px| Different treatment of corners during rotation ]]

Latest revision as of 09:33, 13 October 2017

When rotating a cube, the cube representing the rotated particle will have some areas where there is no information.

As a consequence, a rotated particle appears as showing an "edge". Most Dynamo programs rotate the volume into an sphere. However, sometimes it is necessary to keep the edges, for instance during fourier compensation during average


See the effect here:

u1=dynamo_rot(rand(64,64,64),[45,45,45]); % rotates creating a spherical halo
u2=dpkgeom.rotation.sharpRot(rand(64,64,64),[45,45,45]); % rotates creating an edge
figure;
subplot(1,2,1);dslices(u1);subplot(1,2,2);dslices(u2);


Different treatment of corners during rotation