Sergio Garcia sgarciav

Suppose you have a directory with files named rb_001.png and so on with increasing numbers. And you want to rename the rgb part of the name to image. You'll cd into that directory and execute:

find . -type f -exec rename 's/rgb/image/' '{}' \;

You'll need to install:

sudo apt-get update && sudo apt-get install rename

See: https://askubuntu.com/questions/1241202/cant-access-webcam-settings

  $ sudo apt install v4l-utils
  $ v4l2-ctl --list-devices
  $ v4l2-ctl -d /dev/videoX --list-ctrls
  $ v4l2-ctl --device /dev/video3 --set-ctrl=zoom_absolute=120

Instructions

Taken from here:

  ip a # get DEVICE
  sudo ifconfig <DEVICE> up
  nmcli dev wifi list # get SSID
  sudo nmcli --ask dev wifi connect <SSID>

Find the page that hosts the keyworkd:

pdfgrep -in <keyword> <pdf-file>
Extract specific pdf page:

pdftk cat output

About

When you first install Docker, you have to execute its commands with sudo. Follow these steps to add your user to the docker group such that there won't be a need to execute with sudo.

See: https://docs.docker.com/engine/install/linux-postinstall/

Steps

Add the docker group if it doesn't already exist:

Alternative method for displaying an image

This method relies on a static folder. Doesn't work when hosted on the web - which is why I needed to leverage the Google Cloud Storage.

@app.route('/display/<filename>')
def display_image(filename):
    return redirect(url_for('static', filename='processed_imgs/' + filename), code=301)

Syntax to use in html file if wanting to use the display_image function

References

About

Instructions for using git lfs to track large file (greater tham 100MBs). See instructions here.

You can also watch this video to learn about the different features that lfs provides.

$ sudo apt install git-lfs
$ cd /path/to/[GIT REPO]
$ git lfs install
$ git track [filename or type of file you wish to track]

	#include <pcl_ros/transforms.hpp>

	bool transformCloud(pcl::PointCloud<pcl::PointXYZ>::Ptr& cloud,
	const std::string target_frame)
	{
	const std::string source_frame = cloud->header.frame_id;
	geometry_msgs::msg::TransformStamped transform_stamped;
	bool success = getTransform(source_frame, target_frame, transform_stamped);
	if (not success) { return false; }
	pcl_ros::transformPointCloud(cloud, cloud, transform_stamped);

	bool angleBetweenVectors(Eigen::Vector3f u, Eigen::Vector3f v, double& angle_rad)
	{
	float dot_product = u.dot(v);
	float norms = u.norm() * v.norm();

	// Avoid division by zero or invalid acos input
	if (norms == 0) {
	RCLCPP_ERROR(this->get_logger(), "One or both vectors have zero magnitude.");
	return false;
	}