app.py

import streamlit as st
import cv2
from ultralytics import YOLO
import os
import easyocr
from moviepy import ImageSequenceClip

st.title("🚗 PlateVision 🔍")
st.caption("AI-powered license plate detection & recognition from images and videos")

os.makedirs("input", exist_ok=True)
os.makedirs("output", exist_ok=True)

@st.cache_resource
def load_yolo_model():
    return YOLO("best_model.pt")

@st.cache_resource
def load_ocr_reader():
    return easyocr.Reader(['en'], model_storage_directory='model')

def process_and_find_plate(input_path, output_path):
    extension = os.path.splitext(input_path)[1].lower()
    if extension in ['.mp4', '.mkv']:
        return find_plate_on_video(input_path, output_path)
    elif extension in ['.jpg', '.jpeg', '.png']:
        return find_plate_on_image(input_path, output_path)
    else:
        st.error("Unsupported file type")
        return None

def find_plate_on_image(input_path, output_path):
    model = load_yolo_model()
    reader = load_ocr_reader()

    image = cv2.imread(input_path)
    image = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)
    outputs = model.predict(image, verbose=False)

    for output in outputs:
        for box in output.boxes:
            x1, y1, x2, y2 = map(int, box.xyxy[0])
            confidence = box.conf[0]
            roi = image[y1:y2, x1:x2]
            results = reader.readtext(roi)
            plate_num = results[0][1].strip() if results else "Not Visible!"
            cv2.rectangle(image, (x1, y1), (x2, y2), (0, 0, 255), 2)
            cv2.putText(image, f'{confidence*100:.2f}%', (x1, y1 - 20),
                        cv2.FONT_HERSHEY_SIMPLEX, 0.6, (0, 255, 0), 2)
            cv2.putText(image, f'Number: {plate_num}', (x1, y2 + 20),
                        cv2.FONT_HERSHEY_SIMPLEX, 0.6, (0, 255, 0), 2)

    cv2.imwrite(output_path, cv2.cvtColor(image, cv2.COLOR_RGB2BGR))
    return output_path

def find_plate_on_video(input_path, output_path):
    model = load_yolo_model()
    reader = load_ocr_reader()

    cap = cv2.VideoCapture(input_path)
    if not cap.isOpened():
        st.error("Error opening the video")
        return None

    fps = int(cap.get(cv2.CAP_PROP_FPS)) or 25
    total_frames = int(cap.get(cv2.CAP_PROP_FRAME_COUNT)) or 1
    frames = []
    frame_idx = 0
    skip_frame = 3  # ✅ define properly

    progress_bar = st.progress(0, text="🔍 Analyzing video frames...")

    while cap.isOpened():
        ret, frame = cap.read()
        if not ret:
            break

        if frame_idx % skip_frame == 0:
            rgb_frame = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
            outputs = model.predict(rgb_frame, verbose=False)

            for output in outputs:
                for box in output.boxes:
                    x1, y1, x2, y2 = map(int, box.xyxy[0])
                    confidence = box.conf[0]
                    roi = frame[y1:y2, x1:x2]
                    results = reader.readtext(roi)
                    plate_num = results[0][1].strip() if results else "Not Visible!"
                    cv2.rectangle(frame, (x1, y1), (x2, y2), (0, 0, 255), 2)
                    cv2.putText(frame, f'{confidence*100:.2f}%', (x1, y1 - 20),
                                cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0, 255, 0), 2)
                    cv2.putText(frame, f'Number: {plate_num}', (x1, y2 + 20),
                                cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0, 255, 0), 2)

            frames.append(cv2.cvtColor(frame, cv2.COLOR_BGR2RGB))

        frame_idx += 1
        progress = min(frame_idx / total_frames, 1.0)
        progress_bar.progress(progress, text=f"📸 Processed {frame_idx}/{total_frames} frames...")

    cap.release()
    progress_bar.empty()

    # ✅ fix undefined variable (use skip_frame)
    output_fps = max(fps // skip_frame, 1)
    clip = ImageSequenceClip(frames, fps=output_fps)
    clip.write_videofile(output_path, codec='libx264', audio=False, logger=None)

    return output_path

uploaded_file = st.file_uploader("📤 Upload an image or video", type=['jpg', 'jpeg', 'png', 'mp4', 'mkv'])

if uploaded_file is not None:
    input_path = f"input/{uploaded_file.name}"
    output_path = f"output/{uploaded_file.name}"
    with open(input_path, 'wb') as f:
        f.write(uploaded_file.getbuffer())

    with st.spinner("🚦 Detecting plates... please fasten your seatbelt!"):
        path = process_and_find_plate(input_path, output_path)

    if path and path.endswith(('.mp4', '.mkv')):
        with open(path, 'rb') as video_file:
            st.video(video_file.read())
    elif path and path.endswith(('.jpg', '.jpeg', '.png')):
        st.image(path)
    else:
        st.error("Error occurred while processing the file.")