OpenCV  4.1.0
Open Source Computer Vision
Adding a Trackbar to our applications!


In this tutorial you will learn how to:


Let's modify the program made in the tutorial Adding (blending) two images using OpenCV. We will let the user enter the \(\alpha\) value by using the Trackbar.

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We only analyze the code that is related to Trackbar:

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Note the following (C++ code):

Finally, we have to define the callback function on_trackbar for C++ and Python code, using an anonymous inner class listener in Java

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Note that (C++ code):