How can I create 3D pixels image

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Marcelo hernandez
Marcelo hernandez on 26 Oct 2018
Answered: Image Analyst on 30 Oct 2018
I need to create a sphere in a box of 100 pixels per side
The code to form a circle is the following
imageSizeX = 100;
imageSizeY = 100;
[columnsInImage rowsInImage] = meshgrid(1:imageSizeX, 1:imageSizeY);
% Next create the circle in the image.
centerX = 50;
centerY = 50;
radius = 25;
circlePixels = (rowsInImage - centerY).^2 + (columnsInImage - centerX).^2 <= radius.^2;
% circlePixels is a 2D "logical" array.
% Now, display it.
image(circlePixels) ;
colormap([0 0 0; 1 1 1]);
imwrite(circlePixels,'circle.bmp');
How could the previous code be modified for a sphere?
  1 Comment
Rik
Rik on 26 Oct 2018
Today I formatted your code, next time, use the {}Code button. See here for a GIF showing how to do it.

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Answers (3)

Rik
Rik on 26 Oct 2018
The code generating the binary mask is relatively easy to extend, but you'll have to think about the image format you want to save it in, and the way you want to show the 3D object in a Matlab figure.
imageSizeX = 100;
imageSizeY = 100;
imageSizeZ = 100;
[X,Y,Z] = ndgrid(1:imageSizeX, 1:imageSizeY, 1:imageSizeZ);
% Next create the circle in the image.
centerX = 50;
centerY = 50;
centerZ = 50;
radius = 25;
circlePixels = (Z-centerZ).^2 + (Y-centerY).^2 + (X-centerX).^2 <= radius.^2;
  7 Comments
Rik
Rik on 30 Oct 2018
Did this suggestion solve your problem? If so, please consider marking it as accepted answer. It will make it easier for other people with the same question to find an answer. If this didn't solve your question, please comment with what problems you are still having.

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tesarj13
tesarj13 on 26 Oct 2018
Edited: tesarj13 on 26 Oct 2018
imageSizeX = 100;
imageSizeY = 100;
imageSizeZ = 100;
[columnsInImage, rowsInImage,zInImage] =...
meshgrid(1:imageSizeX, 1:imageSizeY,1:imageSizeZ);
% Next create the circle in the image.
centerY = 50;
centerX = 50;
centerZ = 50;
radius = 25;
circlePixels = (rowsInImage - centerY).^2 + (columnsInImage - centerX).^2 +...
(zInImage - centerZ).^2 <= radius.^2;
% circlePixels is a 3D "logical" array. % Now, display it.
isosurface (circlePixels,1/2)
axis equal

Image Analyst
Image Analyst on 30 Oct 2018
Try this:
[x,y,z] = sphere;
% Plot a sphere centered at the origin.
% Make radius 50
radius = 50;
x = radius * x;
y = radius * y;
z = radius * z;
surf(x,y,z)
grid on;
axis equal

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