简单Projection的矩阵表示Projections of an image onto the x or y axi

Projections of an image onto the x or y axis using Matrix Transformations

投影到X轴
the transformation (x,y) -> (x, 0) projects the point (x,y) onto the x-axis. In matrix form this transformation is given by:

\left[ \begin{matrix} 1 & 0 \\ 0 & 0 \end{matrix} \right]

投影到y轴
the transformation (x,y) => (0, y) projects the point (x,y) onto the y-axis. In matrix form this transformation is given by:

\left[ \begin{matrix} 0 & 0 \\ 0 & 1 \end{matrix} \right]

Reflection对称

Reflection in the line y = x & y = -x 关于y = x的矩阵表示：

\left[ \begin{matrix} 0 & 1 \\ 1 & 0 \end{matrix} \right]

关于y = -x的矩阵表示：

\left[ \begin{matrix} 0 & -1 \\ -1 & 0 \end{matrix} \right]

关于y = mx的矩阵表示 y = xtan(θ)

\left[ \begin{matrix} cos(2θ) & sin(2θ) \\ sin(2θ) & -cos(2θ) \end{matrix} \right]