OpenCV By Example

Feature extraction

Now, let's extract the features of each object. To understand the feature concept of a feature vector, we will extract very simple features, but it is enough to get good results. In other solutions, we can get more complex features, such as texture descriptors, contour descriptors, and so on.

In our example, we only have these three types of objects, nuts, rings, and screws, in different possible positions. All these possible objects and positions are shown in the following figure:

We will explore the good characteristics that will help the computer to identify each object. The characteristics are as follows:

• The area of an object ...