Welcome to DOFBOT Pro repository

21.Hough linear detection

This section is a dedicated course for the Jetson-Nano mainboard. The Orin mainboard does not have a ROS1 environment and cannot run the following programs. The startup commands for this section are run on the Jetson-Nano host machine (mainboard). Simply open a terminal directly on the mainboard and enter the course commands; there is no need to run them in Docker.

21.1. Use

Source code launch file path: ~/dofbot_ws/src/opencv_apps/launch

Step 1: Start the camera

roslaunch dofbot_visual opencv_apps.launch img_flip:=false

• img_flip parameter: whether the image needs to be flipped horizontally, the default is false.

Step 2: Start the corner detection function of Opencv_apps

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roslaunch opencv_apps hough_lines.launch                  # Hough linear detection

Each functional case will have a parameter [debug_view], Boolean type, whether to use Opencv to display images, which is displayed by default.

If no display is required, set it to [False], for example

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roslaunch opencv_apps contour_moments.launch debug_view:=False

However, after starting in this way, some cases cannot be displayed in other ways, because in the source code, some [debug_view] is set to [False], which will turn off image processing.

21.2 Display method

• rqt_image_view

Enter the following command to select the corresponding topic

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rqt_image_view

• opencv

The system displays it by default, no need to do anything.

21.3 Effect display

The lower the threshold, the more lines there are and the easier it is for the picture to freeze.