3D Matrices projections

Hi everyone, I have a 3D metrics and I want to project it to different directions let's say along x, y, z, and different diagonal (0-360) angles, any suggestions pleases

[Walter Roberson]

What form of projection are you interested in? For example do you want maximum intensity along an angle?

[adil alazzawi]

Thanks for your response, I want to average them

Answer 1

[Matt J]

This may be of some help,

https://www.mathworks.com/matlabcentral/fileexchange/56527-fast-raytracing-through-a-3d-grid

[Walter Roberson]

Though that only gives indices of locations that the line interesect, and does not give any information usable for weighting.

It looks like there are a fair number of methods available; https://pdfs.semanticscholar.org/c841/d03ccd8098e3fa1b2a82244e1b8eaff1e567.pdf

Answer 2

[Matt J]

You could also use rotation to align the projection rays with an axis of the image and then use mean(). For example, to take the mean along rays 30 degrees to the columns,

mean(imrotate(yourVolume,30),1)

For rays not parallel to the xy-plane you could use imrotate3 in a similar fashion.

[Walter Roberson]

Note that the rotation angle is generally the negative of what you would think, to move the data with that angle to be aligned with the axes.