From 0dbb1068ad20566ffa376ea1a17231f7d95f482b Mon Sep 17 00:00:00 2001 From: NotXia <35894453+NotXia@users.noreply.github.com> Date: Mon, 24 Jun 2024 17:12:07 +0200 Subject: [PATCH] Fix typos --- .../module1/sections/_instance_obj_detection.tex | 2 +- .../module1/sections/_local_features.tex | 4 ++-- .../module1/sections/_spatial_filtering.tex | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-) diff --git a/src/year1/image-processing-and-computer-vision/module1/sections/_instance_obj_detection.tex b/src/year1/image-processing-and-computer-vision/module1/sections/_instance_obj_detection.tex index b9efea9..44fa050 100644 --- a/src/year1/image-processing-and-computer-vision/module1/sections/_instance_obj_detection.tex +++ b/src/year1/image-processing-and-computer-vision/module1/sections/_instance_obj_detection.tex @@ -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} \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: \[ S(T, \tilde{I}_{i,j}) = \frac{1}{n} \sum_{k=1}^{n} \vec{u}_k(P_k) \cdot \tilde{\vec{u}}_k(\tilde{P}_k) = \frac{1}{n} \sum_{k=1}^{n} \cos \theta_k \in [-1, 1] \] $S(T, \tilde{I}_{i,j}) = 1$ when the gradients perfectly match. A minimum threshold $S_\text{min}$ is used to determine if there is a match. \end{enumerate} diff --git a/src/year1/image-processing-and-computer-vision/module1/sections/_local_features.tex b/src/year1/image-processing-and-computer-vision/module1/sections/_local_features.tex index 8f10f4f..7c4747d 100644 --- a/src/year1/image-processing-and-computer-vision/module1/sections/_local_features.tex +++ b/src/year1/image-processing-and-computer-vision/module1/sections/_local_features.tex @@ -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 $\matr{M}_w$, 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} 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: \begin{enumerate} \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. \item The descriptor is obtained by concatenating the histograms of each region. This results in a feature vector with $128$ elements ($(4 \cdot 4) \cdot 8$). diff --git a/src/year1/image-processing-and-computer-vision/module1/sections/_spatial_filtering.tex b/src/year1/image-processing-and-computer-vision/module1/sections/_spatial_filtering.tex index 1261381..64b8225 100644 --- a/src/year1/image-processing-and-computer-vision/module1/sections/_spatial_filtering.tex +++ b/src/year1/image-processing-and-computer-vision/module1/sections/_spatial_filtering.tex @@ -408,7 +408,7 @@ where $\tilde{I}(p)$ is the real information. \end{descriptionlist} 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} O(p) &= \sum_{q \in \mathcal{N}(p)} H(p, q) \cdot \texttt{intensity}(q) \\