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Hi,

Opencv uses a perpective transformation matrix Q to convert pixels with disparity value into the corresponding x, y, z. After searching on this site for a bit I found out that the matrix Q is as follows:

Q = |1 0 0 -Cx
    |0 1 0 -Cy
    |0 0 0 f
    |0 0 -1/Tx (Cx - Cx')/Tx

I looked for equations to derive this and I know about this formula:

Is there a way to work back from this to get Q or am I missing something?

Thank you

Hi,

Opencv uses a perpective transformation matrix Q Q to convert pixels with disparity value into the corresponding x, [x, y, z. z]. After searching on this site for a bit I found out that the matrix Q is as follows:

Q = |1 0 0 -Cx
    |0 1 0 -Cy
    |0 0 0 f
    |0 0 -1/Tx (Cx - Cx')/Tx

I looked for equations to derive this and but couldn't find any. I know about this formula:

Is there a way to work back from this to get Q or am I missing something?

I'm also confused as to what the Cx' is?

Thank you

Hi,

Opencv uses a perpective transformation matrix Q to convert pixels with disparity value into the corresponding [x, y, z]. using the reprojectImageTo3D function. After searching on this site for a bit I found out that the matrix Q is as follows:

Q = |1 0 0 -Cx
    |0 1 0 -Cy
    |0 0 0 f
    |0 0 -1/Tx (Cx - Cx')/Tx

I looked for equations to derive this but couldn't find any. I know about this formula:

Is there a way to work back from this to get Q or am I missing something?

I'm also confused as to what the Cx' is?

Thank you

Hi,

Opencv uses a perpective transformation matrix Q to convert pixels with disparity value into the corresponding [x, y, z] using the reprojectImageTo3D function. After searching on this site for a bit I found out that the matrix Q is as follows:

Q = |1 0 0 -Cx
    |0 1 0 -Cy
    |0 0 0 f
    |0 0 -1/Tx (Cx - Cx')/Tx

I looked for equations to derive this but couldn't find any. I know about this formula: these matrix equations:

Is there a way to work back from back/invert this to get Q the matrix form of Q or am I missing something?

I'm also confused as to what the Cx' is?

Thank you

Hi,

Opencv uses a perpective transformation matrix Q to convert pixels with disparity value into the corresponding [x, y, z] using the reprojectImageTo3D function. After searching on this site for a bit I found out that the matrix Q is as follows:

Q = |1 0 0 -Cx
    |0 1 0 -Cy
    |0 0 0 f
    |0 0 -1/Tx (Cx - Cx')/Tx

I looked for equations to derive this but couldn't find any. I know about these matrix equations:

Is there a way to work back/invert this to get the matrix form of Q or am I missing something?

edit: projection matrices are the follows:

Pright = |F skew Cx F*Tx
     |0 Fy Cy 0
     |0 0 1 0

and a similar one for Pleft without the Tx factor. I guess what I'm also confused as to what the Cx' is? looking for is a derivation from the projection matrix Pright to the reprojection matrix Q. I would assume there's an inversion or something to get from one to the other.

Thank you

Hi,

Opencv uses a perpective transformation matrix Q to convert pixels with disparity value into the corresponding [x, y, z] using the reprojectImageTo3D function. After searching on this site for a bit I found out that the matrix Q is as follows:

Q = |1 0 0 -Cx
    |0 1 0 -Cy
    |0 0 0 f
    |0 0 -1/Tx (Cx - Cx')/Tx

I looked for equations to derive this but couldn't find any. I know about these matrix equations:

Is there a way to work back/invert this to get the matrix form of Q or am I missing something?

edit: projection matrices are the follows:

Pright = |F skew Cx F*Tx
      |0 Fy Cy 0
      |0 0 1 0

and a similar one for Pleft without the Tx factor. I guess what I'm looking for is a derivation from the projection matrix Pright to the reprojection matrix Q. I would assume there's an inversion or something to get from one to the other.

Thank you