To visualize and detect the trajectory of a bowling ball from a video 1. Preprocessing the Video - Use OpenCV (cv2) to read frames from the video. - Convert frames to grayscale and apply filtering to reduce noise. 2. Object Detection (Ball Tracking) Multiple techniques to detect the bowling ball: A. Background Subtraction - If the background is mostly static, use cv2.createBackgroundSubtractorMOG2(). - This helps to extract moving objects (the ball). B. Color-Based Detection (If Ball Has a Distinct Color) - Convert the frame to HSV color space. - Use cv2.inRange() to create a mask for the ball's color. C. Hough Circle Transform (For Spherical Objects) - Use cv2.HoughCircles() to detect circular shapes. D. Deep Learning-Based Detection - If the ball is not easily detected with the above methods, you can use a pre-trained YOLO or SSD object detection model. 3. Tracking the Ball's Trajectory Once the ball is detected in each frame: - Store its (x, y) coordinates over time. - Use matplotlib to visualize the trajectory. 4. Curve Fitting for Smooth Trajectory - Use numpy.polyfit() to fit a curve (e.g., quadratic fit) to the detected trajectory. - Overlay the predicted trajectory on the video frames. ___________________________________________________________________________________________________________________________________________ | Feature | OpenCV | CNN | |-----------------------------|--------------------------------------|-------------------------------------| | **Speed** | ✅ Faster on CPU | ❌ Slower without GPU | | **Accuracy** | ❌ Sensitive to noise | ✅ More robust to variations | | **Setup Complexity** | ✅ No training needed | ❌ Requires dataset & training | | **Lighting Variance** | ❌ Affected by shadows & reflections | ✅ More resilient | | **Real-Time Performance** | ✅ Works well on low-power devices | ✅ If optimized with TensorRT/ONNX | | **Robustness to Occlusion** | ❌ Fails easily | ✅ Handles occlusion better | | **Customizability** | ✅ Easy to tweak parameters | ❌ Harder to interpret results | - If you need a quick, CPU-friendly, and easily interpretable solution: OpenCV (edge detection, background subtraction, Hough Circles, or simple tracking). - If you need high accuracy and robustness to lighting & occlusions: CNN-based object detection (YOLO, SSD, Faster R-CNN). ___________________________________________________________________________________________________________________________________________ Hybrid Approach (Best of Both Worlds) 1. **Use OpenCV for Fast Preprocessing** - Apply background subtraction or edge detection to isolate regions of interest. 2. **Use CNN Only for Final Detection** - Instead of running YOLO on the full frame, run it only on extracted regions to speed up processing. 3. **Tracking with OpenCV (Kalman Filter or Optical Flow)** - Reduce redundant CNN calls by using object tracking after initial detection. ___________________________________________________________________________________________________________________________________________ Do not stop the recording_2 at frame 200. go ahead