OpenALPR による英語ナンバープレート認識（ソースコードと実行結果）

REM Python をシステム領域にインストール
winget install --scope machine --id Python.Python.3.12 -e --silent
REM Python のパス設定
set "PYTHON_PATH=C:\Program Files\Python312"
set "PYTHON_SCRIPTS_PATH=C:\Program Files\Python312\Scripts"
echo "%PATH%" | find /i "%PYTHON_PATH%" >nul
if errorlevel 1 setx PATH "%PATH%;%PYTHON_PATH%" /M >nul
echo "%PATH%" | find /i "%PYTHON_SCRIPTS_PATH%" >nul
if errorlevel 1 setx PATH "%PATH%;%PYTHON_SCRIPTS_PATH%" /M >nul

winget install --scope machine Codeium.Windsurf -e --silent

# OpenALPR による英語ナンバープレート認識
import os, sys, json, tempfile, zipfile, urllib.request, subprocess, time, shutil
try:
    import cv2
except Exception:
    subprocess.check_call([sys.executable, "-m", "pip", "install", "opencv-python"])
    import cv2

URL="https://github.com/openalpr/openalpr/releases/download/v2.3.0/openalpr-2.3.0-win-64bit.zip"
ROOT=os.path.join(os.environ.get("LOCALAPPDATA", tempfile.gettempdir()), "openalpr-2.3.0-win-64bit")
ALPR_EXE=None; CONFIG=None; RUNTIME=None

def ensure_openalpr():
    global ALPR_EXE, CONFIG, RUNTIME
    if not (os.path.isdir(ROOT) and any("alpr.exe" in f for _,_,f in os.walk(ROOT))):
        os.makedirs(ROOT, exist_ok=True)
        zpath=os.path.join(ROOT,"openalpr.zip")
        print("Downloading OpenALPR 2.3.0...")
        urllib.request.urlretrieve(URL, zpath)
        print("Extracting...")
        with zipfile.ZipFile(zpath) as zf: zf.extractall(ROOT)
        os.remove(zpath)
    # find alpr.exe
    found=None
    for d,_,f in os.walk(ROOT):
        if "alpr.exe" in f:
            found=os.path.join(d,"alpr.exe"); break
    if not found: raise RuntimeError("alpr.exe not found")
    ALPR_EXE=found
    base=os.path.dirname(found)
    # config file
    for c in [os.path.join(base,"openalpr.conf"),
              os.path.join(base,"etc","openalpr","openalpr.conf")]:
        if os.path.isfile(c): CONFIG=c; break
    if not CONFIG: raise RuntimeError("openalpr.conf not found")
    # runtime_data
    for r in [os.path.join(base,"runtime_data"),
              os.path.join(base,"..","share","openalpr","runtime_data")]:
        if os.path.isdir(r): RUNTIME=os.path.abspath(r); break
    if not RUNTIME: raise RuntimeError("runtime_data not found")

def capture_frame(path):
    cap=cv2.VideoCapture(0, cv2.CAP_DSHOW)
    if not cap.isOpened(): raise RuntimeError("Camera not available")
    time.sleep(0.3)
    ret,frame=cap.read(); cap.release()
    if not ret: raise RuntimeError("Failed to grab frame")
    cv2.imwrite(path, frame)
    return frame

def run_alpr(img, country="us", topn="10"):
    env=os.environ.copy()
    env["OPENALPR_CONFIG_FILE"]=CONFIG
    env["OPENALPR_RUNTIME_DIR"]=RUNTIME
    cmd=[ALPR_EXE, "-c", country, "--json", "-n", topn, img]
    r=subprocess.run(cmd, env=env, stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True, cwd=os.path.dirname(ALPR_EXE))
    if r.returncode!=0 and not r.stdout.strip():
        raise RuntimeError("ALPR error: "+r.stderr.strip())
    return json.loads(r.stdout or "{}")

def main():
    ensure_openalpr()
    with tempfile.TemporaryDirectory() as td:
        img=os.path.join(td,"frame.jpg")
        print("Capturing frame...")
        frame=capture_frame(img)
        print("Recognizing...")
        res=run_alpr(img)

        # 結果を表示
        if "results" in res and res["results"]:
            text=f"{res['results'][0].get('plate','')} ({res['results'][0].get('confidence',0):.1f}%)"
            cv2.putText(frame, text, (30,50), cv2.FONT_HERSHEY_SIMPLEX,1,(0,255,0),2)
        cv2.imshow("Captured Frame", frame)
        print(json.dumps(res, indent=2, ensure_ascii=False))
        cv2.waitKey(0)
        cv2.destroyAllWindows()

if __name__=="__main__":
    try:
        main()
    except Exception as e:
        print("Error:", e)
        sys.exit(1)