backend.components.camera_verification.qrcode.qrcodeService

  1from flask import request, send_file, Response
  2import cv2
  3import numpy as np
  4import hashlib
  5from pyzbar import pyzbar
  6
  7from backend.components.utils.imageUtils import encode_image
  8
  9
 10def generate_qr_code(secret: str):
 11    '''
 12    Generates a QR code image from given secret.
 13
 14    **Parameters**:
 15    - `secret` (str): Secret to be encoded.
 16
 17    **Returns**:
 18    - `bytes`: QR code image bytes encoded as PNG 
 19    '''
 20    encoder = cv2.QRCodeEncoder().create()
 21    scale = 12
 22    qr = encoder.encode(secret)
 23
 24    qr = cv2.resize(qr, None, fx=scale, fy=scale, interpolation=cv2.INTER_NEAREST)
 25
 26    border = 4 * scale
 27    qr = cv2.copyMakeBorder(
 28        qr, border, border, border, border,
 29        cv2.BORDER_CONSTANT, value=255
 30    )
 31
 32    _, qr = cv2.threshold(qr, 127, 255, cv2.THRESH_BINARY)
 33    return encode_image(qr)
 34
 35
 36def decode_qr_image(img) -> str:
 37    """
 38    Input an image loaded into numpy array and return decoded QR code data as string.
 39    Uses pyzbar.
 40
 41    **Parameters**:
 42    - `img` (ndarray): Decoded image in ndarray.
 43
 44    **Returns**:
 45    - `str`: Decoded QR code
 46    """
 47    decoded_texts = pyzbar.decode(img)
 48    if decoded_texts and len(decoded_texts)>0:
 49        valid_codes = [code for code in decoded_texts if code]
 50        count = len(valid_codes)
 51
 52        if count == 1:
 53            return valid_codes[0].data.decode("utf-8")
 54        elif count > 1:
 55            raise MultipleCodesError(f"Wykryto {count} kodów QR. Wymagany jest dokładnie jeden.")
 56        else:
 57            raise NoCodeFoundError("Wykryto wzorzec QR, ale nie udało się go odczytać.")
 58
 59    raise NoCodeFoundError("Nie wykryto kodu QR.")
 60
 61
 62@DeprecationWarning
 63def decode_qr_image_legacy(img) -> str:
 64    """
 65    [DEPRECATED] Input an image loaded into numpy array and return decoded QR code data as string.
 66    Uses cv2 detector.
 67
 68    **Parameters**:
 69    - `img` (ndarray): Decoded image in ndarray.
 70
 71    **Returns**:
 72    - `str`: Decoded QR code
 73    """
 74    qr_detector = cv2.QRCodeDetector()
 75    retval, decoded_info, points, straight_qrcode = qr_detector.detectAndDecodeMulti(img)
 76    if retval and decoded_info is not None:
 77        valid_codes = [code for code in decoded_info if code]
 78        count = len(valid_codes)
 79
 80        if count == 1:
 81            return valid_codes[0]
 82        elif count > 1:
 83            raise MultipleCodesError(f"Wykryto {count} kodów QR. Wymagany jest dokładnie jeden.")
 84        else:
 85            raise NoCodeFoundError("Wykryto wzorzec QR, ale nie udało się go odczytać.")
 86
 87    raise NoCodeFoundError("Nie wykryto kodu QR.")
 88
 89
 90class QRCodeError(Exception):
 91    """Base error class for QR codes"""
 92    pass
 93
 94class MultipleCodesError(QRCodeError):
 95    """Raised when more than one code is detected"""
 96    pass
 97
 98class NoCodeFoundError(QRCodeError):
 99    """Raised when no code is detected"""
100    pass
101
102class InvalidCodeError(QRCodeError):
103    """Raised when invalid code is detected"""
104    pass
105
106class ExpiredCodeError(QRCodeError):
107    """Raised when the QR code is expired"""
108    pass