Computer Vision: Object Detection and Image Classification with YOLO

Build real-time visual AI applications

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Computer Vision: Object Detection and Image Classification with YOLO

Build real-time visual AI applications

Practical guide to computer vision using YOLO v8 and modern vision models. Build object detection, classification, and segmentation systems for real-world applications in retail, security, and manufacturing.

computer-visionyoloobject-detectionimage-classificationcv

Computer Vision with YOLO v8

Applications of Object Detection

  • Retail: Inventory counting, shelf analysis
  • Security: Perimeter monitoring, crowd detection
  • Manufacturing: Defect detection, quality control
  • Healthcare: Medical image analysis
  • Autonomous vehicles: Scene understanding
  • Getting Started with YOLO v8

    python
    from ultralytics import YOLO
    import cv2

    Load pre-trained model

    model = YOLO("yolov8n.pt") # n=nano, s=small, m=medium, l=large, x=xlarge

    Run inference on image

    results = model("image.jpg")

    Process results

    for result in results: boxes = result.boxes # Bounding boxes for box in boxes: x1, y1, x2, y2 = box.xyxy[0].tolist() confidence = box.conf[0].item() class_id = int(box.cls[0]) class_name = model.names[class_id] print(f"{class_name}: {confidence:.2f} at [{x1:.0f}, {y1:.0f}, {x2:.0f}, {y2:.0f}]")

    Real-Time Video Detection

    python
    def process_video_stream(source: str = 0):  # 0 = webcam
        cap = cv2.VideoCapture(source)
        model = YOLO("yolov8n.pt")
        
        while cap.isOpened():
            ret, frame = cap.read()
            if not ret:
                break
            
            results = model(frame, verbose=False)
            annotated_frame = results[0].plot()
            
            cv2.imshow("Detection", annotated_frame)
            if cv2.waitKey(1) & 0xFF == ord('q'):
                break
        
        cap.release()
        cv2.destroyAllWindows()
    

    Fine-Tuning for Custom Objects

    python
    

    Prepare dataset in YOLO format

    dataset/

    images/train/ images/val/

    labels/train/ labels/val/

    data.yaml

    data.yaml

    yaml_content = """ train: ./images/train val: ./images/val nc: 3 # number of classes names: ['product', 'defect', 'barcode'] """

    Train custom model

    model = YOLO("yolov8m.pt") # Start from pretrained results = model.train( data="data.yaml", epochs=100, imgsz=640, batch=16, device=0 # GPU index )

    Instance Segmentation

    Get pixel-precise masks, not just boxes:
    python
    seg_model = YOLO("yolov8n-seg.pt")
    results = seg_model("image.jpg")
    masks = results[0].masks.data  # Segmentation masks
    

    Deployment for Production

  • Export to ONNX for cross-platform deployment
  • TensorRT optimization for NVIDIA GPUs (10x speedup)
  • Edge deployment with Coral TPU or NVIDIA Jetson
  • 相关工具

    ultralyticsopencvpytorchonnx