Ball Detection
Design Choice
Vision based ball detection was almost a given if we take into account the fact that we are searching for non-tracking or invasive method. Nevertheless, several methods were researched and compared:
The final design choice was to use the color detection method and it was made based on the amount of previous experience, non-invasive, robustness and easy to implement criteria.
Methodology
Color detection methods are based on removing pixels that do not pass a certain pre-defined color threshold. Thus, filtering will output an image with only the color based pixels we are looking for. From that point onwards, matching and selecting the object becomes the main concern. For selecting the ball candidate, a circular shape matching will be used taking into account that a ball will be seen as a circle from all perspectives, assuming there is no occlusion.
The whole detection process can be divided into two main parts:
- Color based filtering
- Circular shape matching