Add script to generate aruco markers

lidarbot_aruco/README.md

@@ -0,0 +1,41 @@
+# Lidarbot Aruco package
+
+## Generate ArUco marker
+
+The `opencv-contrib-python` module needs to be installed and not `opencv-python`: 
+
+```
+pip uninstall opencv-python
+pip install opencv-contrib-python
+```
+The computer might need to be restarted for the install to be effected.
+
+Next navigate to the path in the `lidarbot_aruco` directory:
+
+```
+cd ~/dev_ws/lidarbot_aruco/lidarbot_aruco
+```
+
+Then run the following script:
+
+```python
+python generate_aruco_marker.py --id 24 --type DICT_4X4_50 \
+	--output ../tags/DICT_4X4_50_id24.png
+```
+
+The script arguments:
+
+`--id` : The unique identifier of the ArUco tag — this is a required argument and ID must be a valid ID in the ArUco dictionary used to generate the tag
+
+`--type` : The name of the ArUco dictionary used to generate the tag; the default type is `DICT_4X4_50`
+
+`--output` : The path to the output image where the generated ArUco tag will be saved; this is a required argument
+
+Running the previous script opens a window with the generated ArUco tag displayed,
+
+<p align='center'>
+    <img src=../docs/images/generated_aruco_marker.png width="400">
+</p>
+
+To close the window, press the **q** key on the keyboard on the opened window.
+

lidarbot_aruco/lidarbot_aruco/generate_aruco_marker.py

@@ -0,0 +1,89 @@
+#!/usr/bin/env python
+
+# This script generates ArUco markers using OpenCV and Python
+
+# Adapted from https://automaticaddison.com/how-to-create-an-aruco-marker-using-opencv-python/
+# and https://pyimagesearch.com/2020/12/14/generating-aruco-markers-with-opencv-and-python/
+
+import cv2
+import argparse
+import numpy as np
+import sys
+
+# Construct the argument parser and parse the arguments
+ap = argparse.ArgumentParser()
+ap.add_argument(
+    "-o", "--output", required=True, help="path to output image containing ArUCo tag"
+)
+ap.add_argument(
+    "-i",
+    "--id",
+    type=int,
+    required=True,
+    help="ID of ArUCo tag to generate",
+)
+ap.add_argument(
+    "-t",
+    "--type",
+    type=str,
+    default="DICT_4X4_50",
+    help="type of ArUCo tag to generate",
+)
+args = vars(ap.parse_args())
+
+# The different ArUco dictinaries built into OpenCV
+ARUCO_DICT = {
+    "DICT_4X4_50": cv2.aruco.DICT_4X4_50,
+    "DICT_4X4_100": cv2.aruco.DICT_4X4_100,
+    "DICT_4X4_250": cv2.aruco.DICT_4X4_250,
+    "DICT_4X4_1000": cv2.aruco.DICT_4X4_1000,
+    "DICT_5X5_50": cv2.aruco.DICT_5X5_50,
+    "DICT_5X5_100": cv2.aruco.DICT_5X5_100,
+    "DICT_5X5_250": cv2.aruco.DICT_5X5_250,
+    "DICT_5X5_1000": cv2.aruco.DICT_5X5_1000,
+    "DICT_6X6_50": cv2.aruco.DICT_6X6_50,
+    "DICT_6X6_100": cv2.aruco.DICT_6X6_100,
+    "DICT_6X6_250": cv2.aruco.DICT_6X6_250,
+    "DICT_6X6_1000": cv2.aruco.DICT_6X6_1000,
+    "DICT_7X7_50": cv2.aruco.DICT_7X7_50,
+    "DICT_7X7_100": cv2.aruco.DICT_7X7_100,
+    "DICT_7X7_250": cv2.aruco.DICT_7X7_250,
+    "DICT_7X7_1000": cv2.aruco.DICT_7X7_1000,
+    "DICT_ARUCO_ORIGINAL": cv2.aruco.DICT_ARUCO_ORIGINAL,
+}
+
+
+# Main method
+def main():
+
+    # Check that we have a valid ArUco marker
+    if ARUCO_DICT.get(args["type"], None) is None:
+        print("[INFO] ArUco tag of '{}' is not supported".format(args["type"]))
+        sys.exit(0)
+
+    # Load the ArUco dictionary
+    arucoDict = cv2.aruco.getPredefinedDictionary(ARUCO_DICT[args["type"]])
+
+    # Allocate memory for the output ArUCo tag and then draw the ArUCo
+    # tag on the output image
+    print(
+        "[INFO] generating ArUCo tag type '{}' with ID '{}'".format(
+            args["type"], args["id"]
+        )
+    )
+    tag = np.zeros((300, 300, 1), dtype="uint8")
+    cv2.aruco.generateImageMarker(arucoDict, args["id"], 300, tag, 1)
+
+    # Write the generated ArUCo tag to disk and then display it to our
+    # screen
+    cv2.imwrite(args["output"], tag)
+    cv2.imshow("ArUCo Tag", tag)
+
+    # If "q" is pressed on the keyboard on the opened window with the aruco tag
+    # close the window
+    if cv2.waitKey(0) & 0xFF == ord("q"):
+        cv2.destroyAllWindows
+
+
+if __name__ == "__main__":
+    main()

lidarbot_aruco/package.xml

@@ -12,6 +12,8 @@
   <test_depend>ament_pep257</test_depend>
   <test_depend>python3-pytest</test_depend>
 
+  <depend>usb-cam</depend>
+
   <export>
     <build_type>ament_python</build_type>
   </export>