app.py

import gradio as gr
import cv2
import numpy as np
from ultralytics import YOLO

def detect_and_crop_spines(image, model_path):
    # Cache the YOLO model to avoid reloading it for every inference
    if not hasattr(detect_and_crop_spines, 'model'):
        detect_and_crop_spines.model = YOLO(model_path)
    
    # Convert gradio image to CV2 format if needed
    if isinstance(image, str):
        image = cv2.imread(image)
    elif isinstance(image, np.ndarray) and len(image.shape) == 3 and image.shape[2] == 3:
        image = cv2.cvtColor(image, cv2.COLOR_RGB2BGR)
    
    # Add error handling for image loading
    if image is None:
        raise ValueError("Failed to load image")

    # Use confidence threshold and add error handling for predictions
    try:
        results = detect_and_crop_spines.model.predict(image, show=False, conf=0.25)
    except Exception as e:
        return None, f"Error during detection: {str(e)}"

    annotated_image = image.copy()
    
    for det in enumerate(results[0].boxes.xyxy.cpu().numpy()):
        # Get corner points
        points = np.array([[det[0], det[1]], [det[2], det[1]], 
                          [det[2], det[3]], [det[0], det[3]]], dtype=np.float32)
        
        # Get minimum area rectangle
        rect = cv2.minAreaRect(points)
        box = cv2.boxPoints(rect)
        box = np.int0(box)
        
        # Draw rotated rectangle
        cv2.drawContours(annotated_image, [box], 0, (0, 255, 0), 2)
    
    # Convert back to RGB for Gradio
    annotated_image = cv2.cvtColor(annotated_image, cv2.COLOR_BGR2RGB)
    
    return annotated_image, f"Detected {len(results[0].boxes)} book spines"

# Create Gradio interface
demo = gr.Interface(
    fn=detect_and_crop_spines,
    inputs=[
        gr.Image(),
        gr.Text(label="YOLO Model Path", value="yolo11x.pt")
    ],
    outputs=[
        gr.Image(label="Annotated Image"),
        gr.Text(label="Detection Results")
    ],
    title="Book Spine Detector",
    description="Upload an image of a bookshelf to detect book spines using YOLO"
)

# Launch the app
demo.launch()