Hi there,

I've got a problem, which need to solve the derivative of affine transformation.

For example, a 2D affine transform is:

A_T(f_{x,y})=\left( \begin{array}{ccc}<br /> a_{11} & a_{12} & a_{13} \\<br /> a_{21} & a_{22} & a_{23} \\<br /> 0 & 0 & 1 \end{array} \right)<br /> \left( \begin{array}{c}<br /> x \\<br /> y \\<br /> 1 \end{array} \right)=<br /> \left( \begin{array}{c}<br /> x^' \\<br /> y^' \\<br /> 1 \end{array} \right)

Here we got a_{ij}, which are 6 affine parameters. Then if we want to get the partial derivative of each parameter a_{ij}, which is:

\frac{\partial A_T}{\partial a}

May I ask how to solve the equation above please? Thanks.