Fix typos <noupdate>

This commit is contained in:
2024-06-24 17:12:07 +02:00
parent 2de2886e5c
commit 0dbb1068ad
3 changed files with 4 additions and 4 deletions

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@ -97,7 +97,7 @@ Edge-based template matching that works as follows:
\nabla \tilde{I}_{i,j}(\tilde{P}_k) = \begin{pmatrix} \partial_x \tilde{I}_{i,j}(\tilde{P}_k) \\ \partial_y \tilde{I}_{i,j}(\tilde{P}_k) \end{pmatrix} \hspace{2em} \nabla \tilde{I}_{i,j}(\tilde{P}_k) = \begin{pmatrix} \partial_x \tilde{I}_{i,j}(\tilde{P}_k) \\ \partial_y \tilde{I}_{i,j}(\tilde{P}_k) \end{pmatrix} \hspace{2em}
\tilde{\vec{u}}_k(\tilde{P}_k) = \frac{\nabla \tilde{I}_{i,j}(\tilde{P}_k)}{\Vert \nabla \tilde{I}_{i,j}(\tilde{P}_k) \Vert} \tilde{\vec{u}}_k(\tilde{P}_k) = \frac{\nabla \tilde{I}_{i,j}(\tilde{P}_k)}{\Vert \nabla \tilde{I}_{i,j}(\tilde{P}_k) \Vert}
\] \]
\item Compute the similarity as the mean of the cosine similarities of each pair of gradients: \item Compute the similarity as the mean cosine similarity of each pair of gradients:
\[ S(T, \tilde{I}_{i,j}) = \frac{1}{n} \sum_{k=1}^{n} \vec{u}_k(P_k) \cdot \tilde{\vec{u}}_k(\tilde{P}_k) = \frac{1}{n} \sum_{k=1}^{n} \cos \theta_k \in [-1, 1] \] \[ S(T, \tilde{I}_{i,j}) = \frac{1}{n} \sum_{k=1}^{n} \vec{u}_k(P_k) \cdot \tilde{\vec{u}}_k(\tilde{P}_k) = \frac{1}{n} \sum_{k=1}^{n} \cos \theta_k \in [-1, 1] \]
$S(T, \tilde{I}_{i,j}) = 1$ when the gradients perfectly match. A minimum threshold $S_\text{min}$ is used to determine if there is a match. $S(T, \tilde{I}_{i,j}) = 1$ when the gradients perfectly match. A minimum threshold $S_\text{min}$ is used to determine if there is a match.
\end{enumerate} \end{enumerate}

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@ -143,7 +143,7 @@ By developing the error function into matrix form, we obtain the following:
$\matr{R}^T$ is the rotation matrix that aligns the image to the eigenvectors of $\matr{M}_w$, $\matr{R}^T$ is the rotation matrix that aligns the image to the eigenvectors of $\matr{M}_w$,
while the eigenvalues remain the same for any rotation of the same patch. while the eigenvalues remain the same for any rotation of the same patch.
Therefore, the eigenvalues $\lambda_1^{(w)}, \lambda_2^{(w)}$ of $\matr{M}_w$ allow to detect intensity changes along the shift directions: Therefore, the eigenvalues $\lambda_1^{(w)}, \lambda_2^{(w)}$ of $\matr{M}_w$ allow to detect intensity changes along the shift direction:
\[ \[
\begin{split} \begin{split}
E(\Delta x, \Delta y) &= \begin{pmatrix} \Delta x & \Delta y \end{pmatrix} E(\Delta x, \Delta y) &= \begin{pmatrix} \Delta x & \Delta y \end{pmatrix}
@ -450,7 +450,7 @@ After finding the keypoints, a descriptor of a keypoint is computed from the pix
Given a keypoint, SIFT detector works as follows: Given a keypoint, SIFT detector works as follows:
\begin{enumerate} \begin{enumerate}
\item Center on the keypoint a $16 \times 16$ grid divided into $4 \times 4$ regions. \item Center on the keypoint a $16 \times 16$ grid divided into $4 \times 4$ regions.
\item Compute for each region its orientation histogram with eight bins (i.e. bins of size $45^\circ$). \item Compute, for each region, its orientation histogram with eight bins (i.e. bins of size $45^\circ$).
The Gaussian weighting function is centered on the keypoint and has $\sigma$ equal to half the grid size. The Gaussian weighting function is centered on the keypoint and has $\sigma$ equal to half the grid size.
\item The descriptor is obtained by concatenating the histograms of each region. \item The descriptor is obtained by concatenating the histograms of each region.
This results in a feature vector with $128$ elements ($(4 \cdot 4) \cdot 8$). This results in a feature vector with $128$ elements ($(4 \cdot 4) \cdot 8$).

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@ -408,7 +408,7 @@ where $\tilde{I}(p)$ is the real information.
\end{descriptionlist} \end{descriptionlist}
Given a pixel $p$, its neighborhood $\mathcal{N}(p)$ and the variances $\sigma_s$, $\sigma_r$ of two Gaussians, Given a pixel $p$, its neighborhood $\mathcal{N}(p)$ and the variances $\sigma_s$, $\sigma_r$ of two Gaussians,
the bilateral filter applied on $p$ is computes as follows: the bilateral filter applied on $p$ is computed as follows:
\[ \[
\begin{split} \begin{split}
O(p) &= \sum_{q \in \mathcal{N}(p)} H(p, q) \cdot \texttt{intensity}(q) \\ O(p) &= \sum_{q \in \mathcal{N}(p)} H(p, q) \cdot \texttt{intensity}(q) \\