OpenCV 4 with Python Blueprints - Second Edition

Storing the data

We will store the data once the user clicks on the Take Snapshot button, and the _on_snapshot event listener method is called, as shown in the following code block:

    def _on_snapshot(self, evt):        """Takes a snapshot of the current frame           This method takes a snapshot of the current frame, preprocesses           it to extract the head region, and upon success adds the data           sample to the training set.        """

Let's take a look at the code inside this method, as follows:

1. First, we figure out the label of the image by finding out which of the radio buttons was selected, like this:

        if self.neutral.GetValue():            label = 'neutral'        elif self.happy.GetValue():            label = 'happy'        elif self.sad.GetValue():            label = 'sad' elif self.surprised.GetValue(): ...