Mastering Computer Vision with TensorFlow 2.x

Contour detection

We first need to import the image and then use the Canny edge detector to find the edges in the image. This works very well as the shape of our object is a circle with a rounded edge. The following is the detailed code required:

threshold =100canny_output = cv2.Canny(img, threshold, threshold * 2)contours, hierarchy = cv2.findContours(canny_output, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)

As the preceding code shows, after Canny edge detection, we applied the OpenCV findContours() method. This method has three arguments:

• The image, which in our case is a Canny edge detector output.
• The retrieval method, which has many options. The one we are using is an external method as we are interested in drawing a bounding box around ...