diff --git a/.github/workflows/ci_docker.yml b/.github/workflows/ci_docker.yml
index fb01f8d..d59eee6 100644
--- a/.github/workflows/ci_docker.yml
+++ b/.github/workflows/ci_docker.yml
@@ -54,6 +54,8 @@ jobs:
           tags: |
             scit0/extract_otp_secret_keys_no_qr_reader:latest
             ghcr.io/scito/extract_otp_secret_keys_no_qr_reader:latest
+            scit0/extract_otp_secret_keys:latest-no-qreader
+            ghcr.io/scito/extract_otp_secret_keys:latest-no-qreader
           # build on feature branches, push only on master branch
           # TODO push: ${{ github.ref == 'refs/heads/master' }}
           push: true
diff --git a/README.md b/README.md
index d5deba5..dd98f6d 100644
--- a/README.md
+++ b/README.md
@@ -20,7 +20,16 @@ cd extract_otp_secret_keys
 
 ## Usage
 
-### With builtin QR decoder
+### Capture QR codes from camera
+
+1. Open "Google Authenticator" app on the mobile phone
+2. Export the QR codes from "Google Authenticator" app
+3. Point the QR codes to the camera of your computer
+4. Call this script with the file as input:
+
+    python extract_otp_secret_keys.py
+
+### With builtin QR decoder from image files
 
 1. Open "Google Authenticator" app on the mobile phone
 2. Export the QR codes from "Google Authenticator" app
@@ -30,7 +39,7 @@ cd extract_otp_secret_keys
 
     python extract_otp_secret_keys.py example_export.png
 
-### With external QR decoder app
+### With external QR decoder app from text files
 
 1. Open "Google Authenticator" app on the mobile phone
 2. Export the QR codes from "Google Authenticator" app
@@ -43,22 +52,28 @@ cd extract_otp_secret_keys
 
 ## Program help: arguments and options
 
-<pre>usage: extract_otp_secret_keys.py [-h] [--json FILE] [--csv FILE] [--keepass FILE] [--printqr] [--saveqr DIR] [--verbose | --quiet] infile [infile ...]
+<pre>usage: extract_otp_secret_keys.py [-h] [--camera NUMBER] [--json FILE] [--csv FILE] [--keepass FILE] [--printqr] [--saveqr DIR] [--verbose | --quiet] [infile ...]
+
+Extracts one time password (OTP) secret keys from QR codes, e.g. from Google Authenticator app.
+If no infiles are provided, the QR codes are interactively captured from the camera.
 
 positional arguments:
-  infile                   1) file or - for stdin with "otpauth-migration://..." URLs separated by newlines, lines starting with # are ignored; or 2) image file containing a QR code or = for stdin for an image containing a QR code
+  infile                      a) file or - for stdin with 'otpauth-migration://...' URLs separated by newlines, lines starting with # are ignored;
+                              b) image file containing a QR code or = for stdin for an image containing a QR code
 
 options:
-  -h, --help               show this help message and exit
-  --json FILE, -j FILE     export json file or - for stdout
-  --csv FILE, -c FILE      export csv file or - for stdout
-  --keepass FILE, -k FILE  export totp/hotp csv file(s) for KeePass, - for stdout
-  --printqr, -p            print QR code(s) as text to the terminal (requires qrcode module)
-  --saveqr DIR, -s DIR     save QR code(s) as images to the given folder (requires qrcode module)
-  --verbose, -v            verbose output
-  --quiet, -q              no stdout output, except output set by -
+  -h, --help                  show this help message and exit
+  --camera NUMBER, -C NUMBER  camera number of system (default camera: 0)
+  --json FILE, -j FILE        export json file or - for stdout
+  --csv FILE, -c FILE         export csv file or - for stdout
+  --keepass FILE, -k FILE     export totp/hotp csv file(s) for KeePass, - for stdout
+  --printqr, -p               print QR code(s) as text to the terminal (requires qrcode module)
+  --saveqr DIR, -s DIR        save QR code(s) as images to the given folder (requires qrcode module)
+  --verbose, -v               verbose output
+  --quiet, -q                 no stdout output, except output set by -
 
 examples:
+python extract_otp_secret_keys.py
 python extract_otp_secret_keys.py example_*.txt
 python extract_otp_secret_keys.py - < example_export.txt
 python extract_otp_secret_keys.py --csv - example_*.png | tail -n+2
@@ -318,6 +333,7 @@ docker run --rm -v "$(pwd)":/files:ro -i extract_otp_secret_keys = < example_exp
 docker run --entrypoint /bin/bash -it --rm -v "$(pwd)":/files:ro extract_otp_secret_keys
 docker run --entrypoint /extract/run_pytest.sh --rm -v "$(pwd)":/files:ro extract_otp_secret_keys
 
+docker login -uscit0
 docker build . -t extract_otp_secret_keys_no_qr_reader -f Dockerfile_no_qr_reader --pull
 docker build . -t extract_otp_secret_keys_no_qr_reader -f Dockerfile_no_qr_reader --pull --build-arg run_tests=false
 docker run --entrypoint /extract/run_pytest.sh --rm -v "$(pwd)":/files:ro extract_otp_secret_keys_no_qr_reader
diff --git a/example_export.txt b/example_export.txt
index 1af539f..6b0fa7e 100644
--- a/example_export.txt
+++ b/example_export.txt
@@ -1,4 +1,5 @@
 # 2FA example from https://www.raspberrypi.org/blog/setting-up-two-factor-authentication-on-your-raspberry-pi/
+
 # Secret key: 7KSQL2JTUDIS5EF65KLMRQIIGY
 # otpauth://totp/pi@raspberrypi?secret=7KSQL2JTUDIS5EF65KLMRQIIGY&issuer=raspberrypi
 otpauth-migration://offline?data=CjUKEPqlBekzoNEukL7qlsjBCDYSDnBpQHJhc3BiZXJyeXBpGgtyYXNwYmVycnlwaSABKAEwAhABGAEgACjr4JKK%2B%2F%2F%2F%2F%2F8B
diff --git a/extract_otp_secret_keys.py b/extract_otp_secret_keys.py
index f467783..0ec87a8 100644
--- a/extract_otp_secret_keys.py
+++ b/extract_otp_secret_keys.py
@@ -45,35 +45,45 @@ import argparse
 import base64
 import csv
 import fileinput
-import importlib
 import json
 import os
 import re
 import sys
 import urllib.parse as urlparse
+from enum import Enum
+from operator import add
+
+from qrcode import QRCode
 
 import protobuf_generated_python.google_auth_pb2
 
-# These dynamic import are below:
-# import cv2
-# import numpy
-# from qreader import QReader
+try:
+    import cv2
+    import numpy
+
+    try:
+        import pyzbar.pyzbar as zbar
+        from qreader import QReader
+    except ImportError as e:
+        abort(f"""
+ERROR: Cannot import QReader module. This problem is probably due to the missing zbar shared library.
+On Linux and macOS libzbar0 must be installed.
+See in README.md for the installation of the libzbar0.
+Exception: {e}""")
+    qreader_available = True
+except ImportError as e:
+    qreader_available = False
+
 
 def sys_main():
     main(sys.argv[1:])
 
 
 def main(sys_args):
-    global verbose, quiet, qreader_available
-
     # allow to use sys.stdout with with (avoid closing)
     sys.stdout.close = lambda: None
-    # sys.stdout.reconfigure(encoding='utf-8')
-
 
     args = parse_args(sys_args)
-    verbose = args.verbose if args.verbose else 0
-    quiet = args.quiet
 
     otps = extract_otps(args)
     write_csv(args, otps)
@@ -82,16 +92,25 @@ def main(sys_args):
 
 
 def parse_args(sys_args):
-    formatter = lambda prog: argparse.RawDescriptionHelpFormatter(prog, max_help_position=52)
-    example_text = '''examples:
+    global verbose, quiet
+    formatter = lambda prog: argparse.RawTextHelpFormatter(prog, max_help_position=52)
+    description_text = "Extracts one time password (OTP) secret keys from QR codes, e.g. from Google Authenticator app."
+    if qreader_available:
+        description_text += "\nIf no infiles are provided, the QR codes are interactively captured from the camera."
+    example_text = """examples:
+python extract_otp_secret_keys.py
 python extract_otp_secret_keys.py example_*.txt
 python extract_otp_secret_keys.py - < example_export.txt
 python extract_otp_secret_keys.py --csv - example_*.png | tail -n+2
-python extract_otp_secret_keys.py = < example_export.png'''
+python extract_otp_secret_keys.py = < example_export.png"""
 
     arg_parser = argparse.ArgumentParser(formatter_class=formatter,
+                                         description=description_text,
                                          epilog=example_text)
-    arg_parser.add_argument('infile', help='1) file or - for stdin with "otpauth-migration://..." URLs separated by newlines, lines starting with # are ignored; or 2) image file containing a QR code or = for stdin for an image containing a QR code', nargs='+')
+    arg_parser.add_argument('infile', help="""a) file or - for stdin with 'otpauth-migration://...' URLs separated by newlines, lines starting with # are ignored;
+b) image file containing a QR code or = for stdin for an image containing a QR code""", nargs='*' if qreader_available else '+')
+    if qreader_available:
+        arg_parser.add_argument('--camera', '-C', help='camera number of system (default camera: 0)', default=0, nargs=1, metavar=('NUMBER'))
     arg_parser.add_argument('--json', '-j', help='export json file or - for stdout', metavar=('FILE'))
     arg_parser.add_argument('--csv', '-c', help='export csv file or - for stdout', metavar=('FILE'))
     arg_parser.add_argument('--keepass', '-k', help='export totp/hotp csv file(s) for KeePass, - for stdout', metavar=('FILE'))
@@ -103,58 +122,122 @@ python extract_otp_secret_keys.py = < example_export.png'''
     args = arg_parser.parse_args(sys_args)
     if args.csv == '-' or args.json == '-' or args.keepass == '-':
         args.quiet = args.q = True
+
+    verbose = args.verbose if args.verbose else 0
+    quiet = True if args.quiet else False
+
     return args
 
 
 def extract_otps(args):
-    global verbose, quiet
-    quiet = args.quiet
+    if not args.infile:
+        return extract_otps_from_camera(args)
+    else:
+        return extract_otps_from_files(args)
 
+
+def extract_otps_from_camera(args):
+    if verbose: print("Capture QR codes from camera")
+    otp_urls = []
     otps = []
 
-    i = j = k = 0
-    if verbose: print('Input files: {}'.format(args.infile))
-    for infile in args.infile:
-        if verbose: print('Processing infile {}'.format(infile))
-        k += 1
-        for line in get_lines_from_file(infile):
-            if verbose: print(line)
-            if line.startswith('#') or line == '': continue
-            i += 1
-            payload = get_payload_from_line(line, i, infile)
+    QRMode = Enum('QRMode', ['QREADER', 'DEEP_QREADER', 'CV2'], start = 0)
+    qr_mode = QRMode.QREADER
+    if verbose: print(f"QR reading mode: {qr_mode}")
 
-            # pylint: disable=no-member
-            for raw_otp in payload.otp_parameters:
-                j += 1
-                if verbose: print('\n{}. Secret Key'.format(j))
-                secret = convert_secret_from_bytes_to_base32_str(raw_otp.secret)
-                otp_type_enum = get_enum_name_by_number(raw_otp, 'type')
-                otp_type = get_otp_type_str_from_code(raw_otp.type)
-                otp_url = build_otp_url(secret, raw_otp)
-                otp = {
-                    "name": raw_otp.name,
-                    "secret": secret,
-                    "issuer": raw_otp.issuer,
-                    "type": otp_type,
-                    "counter": raw_otp.counter if raw_otp.type == 1 else None,
-                    "url": otp_url
-                }
-                if not quiet:
-                    print_otp(otp)
-                if args.printqr:
-                    print_qr(args, otp_url)
-                if args.saveqr:
-                    save_qr(otp, args, j)
-                if not quiet:
-                    print()
+    cam = cv2.VideoCapture(args.camera)
+    window_name = "Extract OTP Secret Keys: Capture QR Codes from Camera"
+    cv2.namedWindow(window_name, cv2.WINDOW_AUTOSIZE)
+    font = cv2.FONT_HERSHEY_PLAIN
+    font_scale = 1
+    font_thickness = 1
+    pos_text = 5, 20
+    font_dy = 0, cv2.getTextSize("M", font, font_scale, font_thickness)[0][1] + 5
+    font_line = cv2.LINE_AA
+    text_color = 255, 255, 255
+    rect_color = 255, 0, 255
+    rect_color_success = 0, 255, 0
+    rect_thickness = 5
+
+    decoder = QReader()
+    while True:
+        success, img = cam.read()
+        if not success:
+            eprint("ERROR: Failed to capture image")
+            break
+        if qr_mode in [QRMode.QREADER, QRMode.DEEP_QREADER]:
+            bbox, found = decoder.detect(img)
+            if qr_mode == QRMode.DEEP_QREADER:
+                otp_url = decoder.detect_and_decode(img)
+            elif qr_mode == QRMode.QREADER:
+                otp_url = decoder.decode(img, bbox) if found else None
+            if found:
+                cv2.rectangle(img, (bbox[0], bbox[1]), (bbox[2], bbox[3]), rect_color_success if otp_url else rect_color, rect_thickness)
+            if otp_url:
+                extract_otps_from_otp_url(otp_url, otp_urls, otps, args)
+        elif qr_mode == QRMode.CV2:
+            for qrcode in zbar.decode(img):
+                otp_url = qrcode.data.decode('utf-8')
+                pts = numpy.array([qrcode.polygon], numpy.int32)
+                pts = pts.reshape((-1, 1, 2))
+                cv2.polylines(img, [pts], True, rect_color_success if otp_url else rect_color, rect_thickness)
+                extract_otps_from_otp_url(otp_url, otp_urls, otps, args)
+        else:
+            assert False, f"ERROR: Wrong QReader mode {qreader.name}"
+
+        cv2.putText(img, f"Mode: {qr_mode.name} (Hit space to change)", pos_text, font, font_scale, text_color, font_thickness, font_line)
+        cv2.putText(img, "Hit ESC to quit", tuple(map(add, pos_text, font_dy)), font, font_scale, text_color, font_thickness, font_line)
+
+        window_dim = cv2.getWindowImageRect(window_name)
+        qrcodes_text = f"{len(otp_urls)} QR code{'s'[:len(otp_urls) != 1]} captured"
+        pos_qrcodes_text = window_dim[2] - cv2.getTextSize(qrcodes_text, font, font_scale, font_thickness)[0][0] - 5, pos_text[1]
+        cv2.putText(img, qrcodes_text, pos_qrcodes_text, font, font_scale, text_color, font_thickness, font_line)
+
+        otps_text = f"{len(otps)} otp{'s'[:len(otps) != 1]} extracted"
+        pos_otps_text = window_dim[2] - cv2.getTextSize(otps_text, font, font_scale, font_thickness)[0][0] - 5, pos_text[1] + font_dy[1]
+        cv2.putText(img, otps_text, pos_otps_text, font, font_scale, text_color, font_thickness, font_line)
+        cv2.imshow(window_name, img)
+
+        key = cv2.waitKey(1) & 0xFF
+        if key == 27 or key == ord('q') or key == 13:
+            # ESC pressed
+            break
+        elif key == 32:
+            qr_mode = QRMode((qr_mode.value + 1) % len(QRMode))
+            if verbose: print(f"QR reading mode: {qr_mode}")
+
+    cam.release()
+    cv2.destroyAllWindows()
 
-                otps.append(otp)
-    if verbose: print('{} infile(s) processed'.format(k))
     return otps
 
 
-def get_lines_from_file(filename):
-    global qreader_available
+def extract_otps_from_otp_url(otp_url, otp_urls, otps, args):
+    if otp_url and verbose: print(otp_url)
+    if otp_url and otp_url not in otp_urls:
+        otp_urls.append(otp_url)
+        extract_otp_from_otp_url(otp_url, otps, len(otp_urls), len(otps), 'camera', args)
+        if verbose: print(f"{len(otps)} otp{'s'[:len(otps) != 1]} from {len(otp_urls)} QR code{'s'[:len(otp_urls) != 1]} extracted")
+
+
+def extract_otps_from_files(args):
+    otps = []
+
+    i = j = k = 0
+    if verbose: print(f"Input files: {args.infile}")
+    for infile in args.infile:
+        if verbose: print(f"Processing infile {infile}")
+        k += 1
+        for line in get_otp_urls_from_file(infile):
+            if verbose: print(line)
+            if line.startswith('#') or line == '': continue
+            i += 1
+            j = extract_otp_from_otp_url(line, otps, i, j, infile, args)
+    if verbose: print(f"{k} infile{'s'[:k != 1]} processed")
+    return otps
+
+
+def get_otp_urls_from_file(filename):
     # stdin stream cannot be rewinded, thus distinguish, use - for utf-8 stdin and = for binary image stdin
     if filename != '=':
         check_file_exists(filename)
@@ -163,45 +246,73 @@ def get_lines_from_file(filename):
             return lines
 
     # could not process text file, try reading as image
-    if filename != '-':
-        return convert_img_to_line(filename)
+    if filename != '-' and qreader_available:
+        return convert_img_to_otp_url(filename)
+
+    return []
 
 
 def read_lines_from_text_file(filename):
-    if verbose: print('Reading lines of {}'.format(filename))
+    if verbose: print(f"Reading lines of {filename}")
     finput = fileinput.input(filename)
     try:
         lines = []
         for line in (line.strip() for line in finput):
             if verbose: print(line)
             if is_binary(line):
-                abort('\nBinary input was given in stdin, please use = instead of - as infile argument for images.')
+                abort("\nBinary input was given in stdin, please use = instead of - as infile argument for images.")
             # unfortunately yield line leads to random test fails
             lines.append(line)
         if not lines:
-            eprint("WARN: {} is empty".format(filename.replace('-', 'stdin')))
+            eprint(f"WARN: {filename.replace('-', 'stdin')} is empty")
         return lines
     except UnicodeDecodeError:
         if filename == '-':
-            abort('\nERROR: Unable to open text file form stdin. '
-            'In case you want read an image file from stdin, you must use "=" instead of "-".')
+            abort("\nERROR: Unable to open text file form stdin. "
+            "In case you want read an image file from stdin, you must use '=' instead of '-'.")
         else: # The file is probably an image, process below
             return None
     finally:
         finput.close()
 
 
-def convert_img_to_line(filename):
-    try:
-        import cv2
-        import numpy
-    except Exception as e:
-        eprint("WARNING: No cv2 or numpy module installed. Exception: {}".format(str(e)))
-        return []
-    if verbose: print('Reading image {}'.format(filename))
+def extract_otp_from_otp_url(otpauth_migration_url, otps, i, j, infile, args):
+    payload = get_payload_from_otp_url(otpauth_migration_url, i, infile)
+
+    # pylint: disable=no-member
+    for raw_otp in payload.otp_parameters:
+        j += 1
+        if verbose: print(f"\n{j}. Secret Key")
+        secret = convert_secret_from_bytes_to_base32_str(raw_otp.secret)
+        otp_type_enum = get_enum_name_by_number(raw_otp, 'type')
+        otp_type = get_otp_type_str_from_code(raw_otp.type)
+        otp_url = build_otp_url(secret, raw_otp)
+        otp = {
+            "name": raw_otp.name,
+            "secret": secret,
+            "issuer": raw_otp.issuer,
+            "type": otp_type,
+            "counter": raw_otp.counter if raw_otp.type == 1 else None,
+            "url": otp_url
+        }
+        otps.append(otp)
+        if not quiet:
+            print_otp(otp)
+        if args.printqr:
+            print_qr(args, otp_url)
+        if args.saveqr:
+            save_qr(otp, args, j)
+        if not quiet:
+            print()
+
+    return j
+
+
+def convert_img_to_otp_url(filename):
+    if verbose: print(f"Reading image {filename}")
     try:
         if filename != '=':
-            image = cv2.imread(filename)
+            img = cv2.imread(filename)
         else:
             try:
                 stdin = sys.stdin.buffer.read()
@@ -213,60 +324,48 @@ def convert_img_to_line(filename):
             try:
                 img_array = numpy.frombuffer(stdin, dtype='uint8')
             except TypeError as e:
-                abort('\nERROR: Cannot read binary stdin buffer. Exception: {}'.format(str(e)))
+                abort(f"\nERROR: Cannot read binary stdin buffer. Exception: {e}")
             if not img_array.size:
                 return []
-            image = cv2.imdecode(img_array, cv2.IMREAD_UNCHANGED)
+            img = cv2.imdecode(img_array, cv2.IMREAD_UNCHANGED)
 
-        if image is None:
-            abort('\nERROR: Unable to open file for reading.\ninput file: {}'.format(filename))
+        if img is None:
+            abort(f"\nERROR: Unable to open file for reading.\ninput file: {filename}")
 
-        # dynamic import of QReader since this module has a dependency to zbar lib and import it only when necessary
-        try:
-            from qreader import QReader
-        except ImportError as e:
-            abort('''
-ERROR: Cannot import QReader module. This problem is probably due to the missing zbar shared library.
-On Linux and macOS libzbar0 must be installed.
-See in README.md for the installation of the libzbar0.
-Exception: {}'''.format(str(e)))
-
-        decoder = QReader()
-        decoded_text = decoder.detect_and_decode(image=image)
+        decoded_text = QReader().detect_and_decode(img)
         if decoded_text is None:
-            abort('\nERROR: Unable to read QR Code from file.\ninput file: {}'.format(filename))
+            abort(f"\nERROR: Unable to read QR Code from file.\ninput file: {filename}")
 
         return [decoded_text]
     except Exception as e:
-        abort('\nERROR: Encountered exception "{}".\ninput file: {}'.format(str(e), filename))
+        abort(f"\nERROR: Encountered exception '{e}'.\ninput file: {filename}")
 
 
-def get_payload_from_line(line, i, infile):
-    global verbose
-    if not line.startswith('otpauth-migration://'):
-        eprint( '\nWARN: line is not a otpauth-migration:// URL\ninput file: {}\nline "{}"\nProbably a wrong file was given'.format(infile, line))
-    parsed_url = urlparse.urlparse(line)
-    if verbose > 1: print('\nDEBUG: parsed_url={}'.format(parsed_url))
+def get_payload_from_otp_url(otpauth_migration_url, i, input_source):
+    if not otpauth_migration_url.startswith('otpauth-migration://'):
+        eprint(f"\nWARN: line is not a otpauth-migration:// URL\ninput: {input_source}\nline '{otpauth_migration_url}'\nProbably a wrong file was given")
+    parsed_url = urlparse.urlparse(otpauth_migration_url)
+    if verbose > 2: print(f"\nDEBUG: parsed_url={parsed_url}")
     try:
         params = urlparse.parse_qs(parsed_url.query, strict_parsing=True)
     except:  # Not necessary for Python >= 3.11
         params = []
-    if verbose > 1: print('\nDEBUG: querystring params={}'.format(params))
+    if verbose > 2: print(f"\nDEBUG: querystring params={params}")
     if 'data' not in params:
-        abort('\nERROR: no data query parameter in input URL\ninput file: {}\nline "{}"\nProbably a wrong file was given'.format(infile, line))
+        abort(f"\nERROR: no data query parameter in input URL\ninput file: {input_source}\nline '{otpauth_migration_url}'\nProbably a wrong file was given")
     data_base64 = params['data'][0]
-    if verbose > 1: print('\nDEBUG: data_base64={}'.format(data_base64))
+    if verbose > 2: print(f"\nDEBUG: data_base64={data_base64}")
     data_base64_fixed = data_base64.replace(' ', '+')
-    if verbose > 1: print('\nDEBUG: data_base64_fixed={}'.format(data_base64))
+    if verbose > 2: print(f"\nDEBUG: data_base64_fixed={data_base64_fixed}")
     data = base64.b64decode(data_base64_fixed, validate=True)
     payload = protobuf_generated_python.google_auth_pb2.MigrationPayload()
     try:
         payload.ParseFromString(data)
     except:
-        abort('\nERROR: Cannot decode otpauth-migration migration payload.\n'
-        'data={}'.format(data_base64))
+        abort(f"\nERROR: Cannot decode otpauth-migration migration payload.\n"
+        f"data={data_base64}")
     if verbose:
-        print('\n{}. Payload Line'.format(i), payload, sep='\n')
+        print(f"\n{i}. Payload Line", payload, sep='\n')
 
     return payload
 
@@ -289,17 +388,17 @@ def build_otp_url(secret, raw_otp):
     url_params = {'secret': secret}
     if raw_otp.type == 1: url_params['counter'] = raw_otp.counter
     if raw_otp.issuer: url_params['issuer'] = raw_otp.issuer
-    otp_url = 'otpauth://{}/{}?'.format(get_otp_type_str_from_code(raw_otp.type), urlparse.quote(raw_otp.name)) + urlparse.urlencode( url_params)
+    otp_url = f"otpauth://{get_otp_type_str_from_code(raw_otp.type)}/{urlparse.quote(raw_otp.name)}?" + urlparse.urlencode(url_params)
     return otp_url
 
 
 def print_otp(otp):
-    print('Name:    {}'.format(otp['name']))
-    print('Secret:  {}'.format(otp['secret']))
-    if otp['issuer']: print('Issuer:  {}'.format(otp['issuer']))
-    print('Type:    {}'.format(otp['type']))
+    print(f"Name:    {otp['name']}")
+    print(f"Secret:  {otp['secret']}")
+    if otp['issuer']: print(f"Issuer:  {otp['issuer']}")
+    print(f"Type:    {otp['type']}")
     if otp['type'] == 'hotp':
-        print('Counter: {}'.format(otp['counter']))
+        print(f"Counter: {otp['counter']}")
     if verbose:
         print(otp['url'])
 
@@ -310,39 +409,34 @@ def save_qr(otp, args, j):
     pattern = re.compile(r'[\W_]+')
     file_otp_name = pattern.sub('', otp['name'])
     file_otp_issuer = pattern.sub('', otp['issuer'])
-    save_qr_file(args, otp['url'], '{}/{}-{}{}.png'.format(dir, j, file_otp_name, '-' + file_otp_issuer if file_otp_issuer else ''))
+    save_qr_file(args, otp['url'], f"{dir}/{j}-{file_otp_name}{'-' + file_otp_issuer if file_otp_issuer else ''}.png")
     return file_otp_issuer
 
 
 def save_qr_file(args, data, name):
-    from qrcode import QRCode
-    global verbose
     qr = QRCode()
     qr.add_data(data)
     img = qr.make_image(fill_color='black', back_color='white')
-    if verbose: print('Saving to {}'.format(name))
+    if verbose: print(f"Saving to {name}")
     img.save(name)
 
 
 def print_qr(args, data):
-    from qrcode import QRCode
     qr = QRCode()
     qr.add_data(data)
     qr.print_ascii()
 
 
 def write_csv(args, otps):
-    global verbose, quiet
     if args.csv and len(otps) > 0:
         with open_file_or_stdout_for_csv(args.csv) as outfile:
             writer = csv.DictWriter(outfile, otps[0].keys())
             writer.writeheader()
             writer.writerows(otps)
-        if not quiet: print("Exported {} otps to csv {}".format(len(otps), args.csv))
+        if not quiet: print(f"Exported {len(otps)} otp{'s'[:len(otps) != 1]} to csv {args.csv}")
 
 
 def write_keepass_csv(args, otps):
-    global verbose, quiet
     if args.keepass and len(otps) > 0:
         has_totp = has_otp_type(otps, 'totp')
         has_hotp = has_otp_type(otps, 'hotp')
@@ -360,7 +454,7 @@ def write_keepass_csv(args, otps):
                             'Title': otp['issuer'],
                             'User Name': otp['name'],
                             'TimeOtp-Secret-Base32': otp['secret'] if otp['type'] == 'totp' else None,
-                            'Group': "OTP/{}".format(otp['type'].upper())
+                            'Group': f"OTP/{otp['type'].upper()}"
                         })
                         count_totp_entries += 1
         if has_hotp:
@@ -374,20 +468,19 @@ def write_keepass_csv(args, otps):
                             'User Name': otp['name'],
                             'HmacOtp-Secret-Base32': otp['secret'] if otp['type'] == 'hotp' else None,
                             'HmacOtp-Counter': otp['counter'] if otp['type'] == 'hotp' else None,
-                            'Group': "OTP/{}".format(otp['type'].upper())
+                            'Group': f"OTP/{otp['type'].upper()}"
                         })
                         count_hotp_entries += 1
         if not quiet:
-            if count_totp_entries > 0: print( "Exported {} totp entries to keepass csv file {}".format(count_totp_entries, otp_filename_totp))
-            if count_hotp_entries > 0: print( "Exported {} hotp entries to keepass csv file {}".format(count_hotp_entries, otp_filename_hotp))
+            if count_totp_entries > 0: print(f"Exported {count_totp_entries} totp entrie{'s'[:count_totp_entries != 1]} to keepass csv file {otp_filename_totp}")
+            if count_hotp_entries > 0: print(f"Exported {count_hotp_entries} hotp entrie{'s'[:count_hotp_entries != 1]} to keepass csv file {otp_filename_hotp}")
 
 
 def write_json(args, otps):
-    global verbose, quiet
     if args.json:
         with open_file_or_stdout(args.json) as outfile:
             json.dump(otps, outfile, indent=4)
-        if not quiet: print("Exported {} otp entries to json {}".format(len(otps), args.json))
+        if not quiet: print(f"Exported {len(otps)} otp{'s'[:len(otps) != 1]} to json {args.json}")
 
 
 def has_otp_type(otps, otp_type):
@@ -420,8 +513,8 @@ def open_file_or_stdout_for_csv(filename):
 
 def check_file_exists(filename):
     if filename != '-' and not os.path.isfile(filename):
-        abort('\nERROR: Input file provided is non-existent or not a file.'
-        '\ninput file: {}'.format(filename))
+        abort(f"\nERROR: Input file provided is non-existent or not a file."
+        f"\ninput file: {filename}")
 
 
 def is_binary(line):
@@ -432,11 +525,6 @@ def is_binary(line):
         return True
 
 
-def check_module_available(module_name):
-    module_spec = importlib.util.find_spec(module_name)
-    return module_spec is not None
-
-
 def eprint(*args, **kwargs):
     '''Print to stderr.'''
     print(*args, file=sys.stderr, **kwargs)
diff --git a/requirements.txt b/requirements.txt
index c57362c..5243777 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,3 +3,4 @@ qrcode
 Pillow
 qreader
 opencv-python
+pyzbar
diff --git a/test/print_verbose_output.txt b/test/print_verbose_output.txt
index cf01dae..d920927 100644
--- a/test/print_verbose_output.txt
+++ b/test/print_verbose_output.txt
@@ -2,6 +2,7 @@ Input files: ['example_export.txt']
 Processing infile example_export.txt
 Reading lines of example_export.txt
 # 2FA example from https://www.raspberrypi.org/blog/setting-up-two-factor-authentication-on-your-raspberry-pi/
+
 # Secret key: 7KSQL2JTUDIS5EF65KLMRQIIGY
 # otpauth://totp/pi@raspberrypi?secret=7KSQL2JTUDIS5EF65KLMRQIIGY&issuer=raspberrypi
 otpauth-migration://offline?data=CjUKEPqlBekzoNEukL7qlsjBCDYSDnBpQHJhc3BiZXJyeXBpGgtyYXNwYmVycnlwaSABKAEwAhABGAEgACjr4JKK%2B%2F%2F%2F%2F%2F8B
@@ -20,6 +21,7 @@ otpauth-migration://offline?data=CiUKEPqlBekzoNEukL7qlsjBCDYSCWhvdHAgZGVtbyABKAE
 # Name: "encoding: ¿äÄéÉ? (demo)"
 otpauth-migration://offline?data=CjYKEPqlBekzoNEukL7qlsjBCDYSHGVuY29kaW5nOiDCv8Okw4TDqcOJPyAoZGVtbykgASgBMAIQARgBIAAorfCurv%2F%2F%2F%2F%2F%2FAQ%3D%3D
 # 2FA example from https://www.raspberrypi.org/blog/setting-up-two-factor-authentication-on-your-raspberry-pi/
+
 # Secret key: 7KSQL2JTUDIS5EF65KLMRQIIGY
 # otpauth://totp/pi@raspberrypi?secret=7KSQL2JTUDIS5EF65KLMRQIIGY&issuer=raspberrypi
 otpauth-migration://offline?data=CjUKEPqlBekzoNEukL7qlsjBCDYSDnBpQHJhc3BiZXJyeXBpGgtyYXNwYmVycnlwaSABKAEwAhABGAEgACjr4JKK%2B%2F%2F%2F%2F%2F8B
@@ -157,4 +159,4 @@ Secret:  7KSQL2JTUDIS5EF65KLMRQIIGY
 Type:    totp
 otpauth://totp/encoding%3A%20%C2%BF%C3%A4%C3%84%C3%A9%C3%89%3F%20%28demo%29?secret=7KSQL2JTUDIS5EF65KLMRQIIGY
 
-1 infile(s) processed
+1 infile processed
diff --git a/test_extract_otp_secret_keys_pytest.py b/test_extract_otp_secret_keys_pytest.py
index 0031971..b62b676 100644
--- a/test_extract_otp_secret_keys_pytest.py
+++ b/test_extract_otp_secret_keys_pytest.py
@@ -28,7 +28,7 @@ import pytest
 import extract_otp_secret_keys
 from utils import *
 
-qreader_available = extract_otp_secret_keys.check_module_available('cv2')
+qreader_available = extract_otp_secret_keys.qreader_available
 
 
 def test_extract_stdout(capsys):
@@ -42,22 +42,6 @@ def test_extract_stdout(capsys):
     assert captured.err == ''
 
 
-@pytest.mark.qreader
-def test_extract_multiple_files_and_mixed(capsys):
-    # Act
-    extract_otp_secret_keys.main([
-        'example_export.txt',
-        'test/test_googleauth_export.png',
-        'example_export.txt',
-        'test/test_googleauth_export.png'])
-
-    # Assert
-    captured = capsys.readouterr()
-
-    assert captured.out == EXPECTED_STDOUT_FROM_EXAMPLE_EXPORT + EXPECTED_STDOUT_FROM_EXAMPLE_EXPORT_PNG + EXPECTED_STDOUT_FROM_EXAMPLE_EXPORT + EXPECTED_STDOUT_FROM_EXAMPLE_EXPORT_PNG
-    assert captured.err == ''
-
-
 def test_extract_non_existent_file(capsys):
     # Act
     with pytest.raises(SystemExit) as e:
@@ -144,26 +128,6 @@ def test_extract_stdin_img_empty(capsys, monkeypatch):
     assert captured.err == 'WARN: stdin is empty\n'
 
 
-@pytest.mark.qreader
-def test_extract_stdin_stdout_wrong_symbol(capsys, monkeypatch):
-    # Arrange
-    monkeypatch.setattr('sys.stdin', io.StringIO(read_file_to_str('example_export.txt')))
-
-    # Act
-    with pytest.raises(SystemExit) as e:
-        extract_otp_secret_keys.main(['='])
-
-    # Assert
-    captured = capsys.readouterr()
-
-    expected_stderr = "\nERROR: Cannot read binary stdin buffer. Exception: a bytes-like object is required, not 'str'\n"
-
-    assert captured.err == expected_stderr
-    assert captured.out == ''
-    assert e.value.code == 1
-    assert e.type == SystemExit
-
-
 def test_extract_csv(capsys):
     # Arrange
     cleanup()
@@ -443,7 +407,7 @@ def test_extract_verbose(capsys, relaxed):
 
 def test_extract_debug(capsys):
     # Act
-    extract_otp_secret_keys.main(['-vv', 'example_export.txt'])
+    extract_otp_secret_keys.main(['-vvv', 'example_export.txt'])
 
     # Assert
     captured = capsys.readouterr()
@@ -469,7 +433,7 @@ def test_extract_help(capsys):
     assert e.type == SystemExit
     assert e.value.code == 0
 
-
+@pytest.mark.skipif(qreader_available, reason="Cannot test interactive mode")
 def test_extract_no_arguments(capsys):
     # Act
     with pytest.raises(SystemExit) as e:
@@ -530,13 +494,13 @@ def test_wrong_content(capsys):
 
     expected_stderr = '''
 WARN: line is not a otpauth-migration:// URL
-input file: test/test_export_wrong_content.txt
-line "Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua."
+input: test/test_export_wrong_content.txt
+line 'Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua.'
 Probably a wrong file was given
 
 ERROR: no data query parameter in input URL
 input file: test/test_export_wrong_content.txt
-line "Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua."
+line 'Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua.'
 Probably a wrong file was given
 '''
 
@@ -555,8 +519,8 @@ def test_wrong_prefix(capsys):
 
     expected_stderr = '''
 WARN: line is not a otpauth-migration:// URL
-input file: test/test_export_wrong_prefix.txt
-line "QR-Code:otpauth-migration://offline?data=CjUKEPqlBekzoNEukL7qlsjBCDYSDnBpQHJhc3BiZXJyeXBpGgtyYXNwYmVycnlwaSABKAEwAhABGAEgACjr4JKK%2B%2F%2F%2F%2F%2F8B"
+input: test/test_export_wrong_prefix.txt
+line 'QR-Code:otpauth-migration://offline?data=CjUKEPqlBekzoNEukL7qlsjBCDYSDnBpQHJhc3BiZXJyeXBpGgtyYXNwYmVycnlwaSABKAEwAhABGAEgACjr4JKK%2B%2F%2F%2F%2F%2F8B'
 Probably a wrong file was given
 '''
 
@@ -588,6 +552,23 @@ def test_img_qr_reader_from_file_happy_path(capsys):
     assert captured.out == EXPECTED_STDOUT_FROM_EXAMPLE_EXPORT_PNG
     assert captured.err == ''
 
+
+@pytest.mark.qreader
+def test_extract_multiple_files_and_mixed(capsys):
+    # Act
+    extract_otp_secret_keys.main([
+        'example_export.txt',
+        'test/test_googleauth_export.png',
+        'example_export.txt',
+        'test/test_googleauth_export.png'])
+
+    # Assert
+    captured = capsys.readouterr()
+
+    assert captured.out == EXPECTED_STDOUT_FROM_EXAMPLE_EXPORT + EXPECTED_STDOUT_FROM_EXAMPLE_EXPORT_PNG + EXPECTED_STDOUT_FROM_EXAMPLE_EXPORT + EXPECTED_STDOUT_FROM_EXAMPLE_EXPORT_PNG
+    assert captured.err == ''
+
+
 @pytest.mark.qreader
 def test_img_qr_reader_from_stdin(capsys, monkeypatch):
     # Arrange
@@ -643,6 +624,26 @@ def test_img_qr_reader_from_stdin_wrong_symbol(capsys, monkeypatch):
     assert e.type == SystemExit
 
 
+@pytest.mark.qreader
+def test_extract_stdin_stdout_wrong_symbol(capsys, monkeypatch):
+    # Arrange
+    monkeypatch.setattr('sys.stdin', io.StringIO(read_file_to_str('example_export.txt')))
+
+    # Act
+    with pytest.raises(SystemExit) as e:
+        extract_otp_secret_keys.main(['='])
+
+    # Assert
+    captured = capsys.readouterr()
+
+    expected_stderr = "\nERROR: Cannot read binary stdin buffer. Exception: a bytes-like object is required, not 'str'\n"
+
+    assert captured.err == expected_stderr
+    assert captured.out == ''
+    assert e.value.code == 1
+    assert e.type == SystemExit
+
+
 @pytest.mark.qreader
 def test_img_qr_reader_no_qr_code_in_image(capsys):
     # Act
@@ -686,13 +687,13 @@ def test_non_image_file(capsys):
     captured = capsys.readouterr()
     expected_stderr = '''
 WARN: line is not a otpauth-migration:// URL
-input file: test/text_masquerading_as_image.jpeg
-line "This is just a text file masquerading as an image file."
+input: test/text_masquerading_as_image.jpeg
+line 'This is just a text file masquerading as an image file.'
 Probably a wrong file was given
 
 ERROR: no data query parameter in input URL
 input file: test/text_masquerading_as_image.jpeg
-line "This is just a text file masquerading as an image file."
+line 'This is just a text file masquerading as an image file.'
 Probably a wrong file was given
 '''
 
diff --git a/test_extract_otp_secret_keys_unittest.py b/test_extract_otp_secret_keys_unittest.py
index 874ef09..acdd851 100644
--- a/test_extract_otp_secret_keys_unittest.py
+++ b/test_extract_otp_secret_keys_unittest.py
@@ -179,7 +179,7 @@ Type:    totp
     def test_extract_debug(self):
         out = io.StringIO()
         with redirect_stdout(out):
-            extract_otp_secret_keys.main(['-vv', 'example_export.txt'])
+            extract_otp_secret_keys.main(['-vvv', 'example_export.txt'])
         actual_output = out.getvalue()
 
         expected_stdout = read_file_to_str('test/print_verbose_output.txt')
diff --git a/test_extract_qrcode_unittest.py b/test_extract_qrcode_unittest.py
index 7f9c718..9152511 100644
--- a/test_extract_qrcode_unittest.py
+++ b/test_extract_qrcode_unittest.py
@@ -65,13 +65,13 @@ class TestQRImageExtract(unittest.TestCase):
         expected_output = [
             '',
             'WARN: line is not a otpauth-migration:// URL',
-            'input file: test/text_masquerading_as_image.jpeg',
-            'line "This is just a text file masquerading as an image file."',
+            'input: test/text_masquerading_as_image.jpeg',
+            "line 'This is just a text file masquerading as an image file.'",
             'Probably a wrong file was given',
             '',
             'ERROR: no data query parameter in input URL',
             'input file: test/text_masquerading_as_image.jpeg',
-            'line "This is just a text file masquerading as an image file."',
+            "line 'This is just a text file masquerading as an image file.'",
             'Probably a wrong file was given'
         ]