I want to apply an affine transform on a 3D MRI volume and recover the parameters used with the affine matrix, such as:
translation (tx, ty, tz)
rotation (rx, ry, rz)
shearing (sx, sy, sz)
scaling (hx, hy, hz)
I am struggling with the shearing matrix, that is usually defined with 6 coefficients:
[1 sxy sxz]
[syx 1 syz]
[szx szy 1]
But I can only recover the initial coefficients with the initial matrix if the shearing is applied only on one direction in each place (syx = szx = szy = 0). Then the shearing matrix is written this way :
[1 sxy sxz]
[0 1 syz]
[0 0 1]
I wanted to used the AffineDTI3DTransform to get directly the shearing coefficients, but then the matrix used is of the form:
[1 sx*sz sx]
[sy 1 0]
[0 sz 0]
Do you know how the shearing is applied with the Affine Transform matrix (3 shearing parameters or 6 parameters) ? Do you know if the AffineDTITransform could be suitable for other MRI images ? Do you know the order of the transormations (translation, rotation, scaling, shearing) in the Affine Transform ?
Hello,
I want to apply an affine transform on a 3D MRI volume and recover the parameters used with the affine matrix, such as:
I am struggling with the shearing matrix, that is usually defined with 6 coefficients: [1 sxy sxz] [syx 1 syz] [szx szy 1]
But I can only recover the initial coefficients with the initial matrix if the shearing is applied only on one direction in each place (syx = szx = szy = 0). Then the shearing matrix is written this way : [1 sxy sxz] [0 1 syz] [0 0 1]
I wanted to used the AffineDTI3DTransform to get directly the shearing coefficients, but then the matrix used is of the form:
[1 sx*sz sx] [sy 1 0] [0 sz 0]
Do you know how the shearing is applied with the Affine Transform matrix (3 shearing parameters or 6 parameters) ? Do you know if the AffineDTITransform could be suitable for other MRI images ? Do you know the order of the transormations (translation, rotation, scaling, shearing) in the Affine Transform ?
Thank you.