Hello friends! Today we will detect circular features in a still image using MATLAB. We will use the bicycle photograph from the original tutorial, locate candidate wheel boundaries and display the estimated centres and radii over the image. The aim is to understand the complete process rather than copy one sensitivity value and expect it to work everywhere. Image size, contrast, the expected radius and the chosen preprocessing all affect the result. We will make those choices explicit and explain how to change them. This is a circle-detection tutorial, not a wheel-recognition system. A circular sign or another rounded object can produce a valid detection too. Once the basic detector works, additional information about position, size or colour can help decide which circles belong to the ob ...