app.py

import gradio as gr
import cv2
import numpy as np
from PIL import Image, ImageDraw
from ultralytics import YOLO
from paddleocr import PaddleOCR
import logging
import os
import requests

# Setup logging
logging.basicConfig(level=logging.INFO)
os.makedirs("debug_outputs", exist_ok=True)

# Path to the YOLOv8 model
model_path = "yolov8-license-plate.pt"  # Replace this with your correct model path or URL

# If model is not available, download it (replace the URL with the correct one)
download_url = "https://your-model-url.com/your-model.pt"  # Replace with actual URL

if not os.path.exists(model_path):
    print(f"Downloading model weights from {download_url}...")
    response = requests.get(download_url)
    with open(model_path, "wb") as f:
        f.write(response.content)

# Load the model (either downloaded or pre-existing)
model = YOLO(model_path)

# PaddleOCR for text recognition
ocr = PaddleOCR(use_angle_cls=True, lang='en')

def locate_plate_within_vehicle(vehicle_crop):
    """Try to locate license plate inside a vehicle region using edge detection"""
    gray = cv2.cvtColor(np.array(vehicle_crop), cv2.COLOR_RGB2GRAY)
    blurred = cv2.bilateralFilter(gray, 11, 17, 17)
    edged = cv2.Canny(blurred, 30, 200)

    contours, _ = cv2.findContours(edged.copy(), cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)
    contours = sorted(contours, key=cv2.contourArea, reverse=True)[:5]

    for c in contours:
        x, y, w, h = cv2.boundingRect(c)
        aspect_ratio = w / float(h)
        if 2 < aspect_ratio < 6 and w > 60:
            plate = vehicle_crop.crop((x, y, x + w, y + h))
            return plate
    return None

def detect_vehicles(image):
    image_np = np.array(image)
    results = model.predict(image_np, conf=0.4)
    vehicle_regions = []

    for result in results:
        if result.boxes is not None:
            boxes = result.boxes.xyxy.cpu().numpy().astype(int)
            classes = result.boxes.cls.cpu().numpy().astype(int)
            for box, cls_id in zip(boxes, classes):
                if cls_id in [2, 3, 5, 7]:  # car, motorcycle, bus, truck
                    x_min, y_min, x_max, y_max = box[:4]
                    vehicle_regions.append((x_min, y_min, x_max, y_max))
    return vehicle_regions

def extract_text_from_plate(plate_image, idx):
    try:
        plate_cv2 = cv2.cvtColor(np.array(plate_image), cv2.COLOR_RGB2BGR)
        cv2.imwrite(f"debug_outputs/preprocessed_plate_{idx}.jpg", plate_cv2)
        result = ocr.ocr(plate_cv2, cls=True)

        if result and isinstance(result, list) and len(result[0]) > 0:
            text = " ".join([line[1][0] for line in result[0]])
            return text.strip()
        return "[No text detected]"
    except Exception as e:
        logging.warning(f"OCR failed: {e}")
        return f"[OCR failed]"

def process_image(image):
    try:
        if isinstance(image, np.ndarray):
            image = Image.fromarray(image)

        draw = ImageDraw.Draw(image)
        vehicles = detect_vehicles(image)

        if not vehicles:
            return image, "No vehicles detected."

        all_texts = []

        for idx, (x_min, y_min, x_max, y_max) in enumerate(vehicles):
            draw.rectangle([x_min, y_min, x_max, y_max], outline="blue", width=2)
            vehicle_crop = image.crop((x_min, y_min, x_max, y_max))
            vehicle_crop.save(f"debug_outputs/vehicle_{idx}.jpg")

            plate_crop = locate_plate_within_vehicle(vehicle_crop)
            if plate_crop:
                plate_crop.save(f"debug_outputs/plate_{idx}.jpg")
                text = extract_text_from_plate(plate_crop, idx)
                all_texts.append(f"Vehicle {idx + 1}: {text}")
            else:
                all_texts.append(f"Vehicle {idx + 1}: [No plate found]")

        return image, "\n".join(all_texts)

    except Exception as e:
        logging.exception("Unexpected error during image processing:")
        return image, f"Error: {str(e)}"

# Gradio UI
with gr.Blocks() as demo:
    gr.Markdown("## 🚘 FREE License Plate Detector (YOLOv8n + OCR)")
    with gr.Row():
        with gr.Column():
            image_input = gr.Image(type="pil", label="Upload or Capture Image")
        with gr.Column():
            image_output = gr.Image(type="pil", label="Detected Vehicles")
            plates_output = gr.Textbox(label="Recognized Number Plates")

    process_button = gr.Button("🔍 Process Image")
    process_button.click(process_image, inputs=image_input, outputs=[image_output, plates_output])

demo.launch()