MATLAB Function Reference |
Reduce the number of elements in a volume data set
Syntax
[nx,ny,nz,nv] = reducevolume(X,Y,Z,V,[Rx,Ry,Rz]) [nx,ny,nz,nv] = reducevolume(V,[Rx,Ry,Rz]) nv = reducevolume(...)
Description
[nx,ny,nz,nv] = reducevolume(X,Y,Z,V,[Rx,Ry,Rz])
reduces the number of elements in the volume by retaining every Rx
th element in the x direction, every Ry
th element in the y direction, and every Rz
th element in the z direction. If a scalar R
is used to indicate the amount or reduction instead of a three-element vector, MATLAB assumes the reduction to be [R R R]
.
The arrays X
, Y
, and Z
define the coordinates for the volume V
. The reduced volume is returned in nv
, and the coordinates of the reduced volume are returned in nx
, ny
, and nz
.
[nx,ny,nz,nv] = reducevolume(V,[Rx,Ry,Rz])
assumes the arrays X
, Y
, and Z
are defined as [X,Y,Z] = meshgrid(1:n,1:m,1:p)
where [m,n,p] = size(V)
.
nv = reducevolume(...)
returns only the reduced volume.
Examples
This example uses a data set that is a collection of MRI slices of a human skull. This data is processed in a variety of ways:
squeeze
) into three dimensions and then reduced (reducevolume
) so that what remains is every fourth element in the x and y directions and every element in the z direction.
smooth3
).
p1
) whose vertex normals are recalculated to improve the appearance when lighting is applied (patch
, isosurface
, isonormals
).
p2
) with an interpolated face color draws the end caps (FaceColor
, isocaps
).
view
, axis
, daspect
).
colormap
).
camlight
, lighting
).
load mri D = squeeze(D); [x,y,z,D] = reducevolume(D,[4,4,1]); D = smooth3(D); p1 = patch(isosurface(x,y,z,D, 5,'verbose'),... 'FaceColor','red','EdgeColor','none'); isonormals(x,y,z,D,p1); p2 = patch(isocaps(x,y,z,D, 5),... 'FaceColor','interp','EdgeColor','none'); view(3); axis tight; daspect([1,1,.4]) colormap(gray(100)) camlight; lighting gouraud
See Also
isosurface
, isocaps
, isonormals
, smooth3
, subvolume
, reducepatch
Volume Visualization for related functions
reducepatch | refresh |
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