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Math and science::Algebra
Sobel operator
The Sobel operator is a first-difference applied after a smoothing.
It can be thought of as a solution to problem that the first difference can be too sensitive to noise.
Convolution matrices, horizontal and vertical
[\[
S_x =
\begin{bmatrix}
? & 0 & ? \\
? & 0 & ? \\
? & 0 & ?
\end{bmatrix}, \quad
S_y \;=\;
\begin{bmatrix}
? & ? & ? \\
0 & 0 & 0 \\
? & ? & ?
\end{bmatrix}
\]]
