Mastering OpenCV 4 with Python

Drawing both text and shapes

In this example, we are combining both mouse events and drawing text. In this sense, some text is rendered to show how to use the mouse events to perform specific actions. To better understand this example, in the next screenshot you can see the rendered text:

You can do the following:

• Add a circle using the double left-click
• Delete the last added circle using a simple left-click
• Delete all circles using the double right-click

To perform this functionality, we create a list called circles, where we maintain the current circles selected by the user. Additionally, we also create a backup image with the rendered ...