diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
new file mode 100644
index 0000000..e51700f
--- /dev/null
+++ b/.gitlab-ci.yml
@@ -0,0 +1,34 @@
+stages:
+  - test-csv
+  - test-image_extensions
+
+variables:
+  PIP_CACHE_DIR: "$CI_PROJECT_DIR/.cache/pip"
+
+cache:
+  key: "$CI_JOB_NAME"
+  paths:
+    - .cache/pip
+
+before_script:
+    - apt-get update
+    - apt-get install -y python3-pyqt5 xvfb
+    - python3 -m venv venv
+    - source venv/bin/activate
+    - python3 -m pip install --upgrade pip
+    - pip3 install -r requirements.txt
+    - pip install pytest pytest-qt
+    - export PYTHONPATH=$PYTHONPATH:$CI_PROJECT_DIR/app
+
+test-csv:
+    stage: test-csv
+    image: python:3.8
+    script:
+        - xvfb-run -a --server-args="-screen 0 1024x768x24" pytest test/test_generate_csv.py --tb=short -v
+
+test-image_extensions:
+  stage: test-image_extensions
+  image: python:3.8
+  script:
+        - xvfb-run -a --server-args="-screen 0 1024x768x24" pytest test/test_img_paths.py --tb=short -v
+
diff --git a/app/.gitkeep b/app/.gitkeep
new file mode 100644
index 0000000..e69de29
diff --git a/main.py b/app/main.py
similarity index 96%
rename from main.py
rename to app/main.py
index 2b16427..0e2ac0d 100644
--- a/main.py
+++ b/app/main.py
@@ -6,13 +6,14 @@
 import numpy as np
 from PyQt5 import QtWidgets
 from PyQt5.QtCore import Qt
-from PyQt5.QtGui import QPixmap, QIntValidator, QKeySequence
+from PyQt5.QtGui import QPixmap, QIntValidator, QKeySequence, QImageReader
 from PyQt5.QtWidgets import QApplication, QWidget, QLabel, QCheckBox, QFileDialog, QDesktopWidget, QLineEdit, \
     QRadioButton, QShortcut, QScrollArea, QVBoxLayout, QGroupBox, QFormLayout
 from xlsxwriter.workbook import Workbook
 
 
-def get_img_paths(dir, extensions=('.jpg', '.png', '.jpeg')):
+def get_img_paths(dir, extensions=tuple(['.' + extension.data().decode('utf-8') for
+                                         extension in QImageReader.supportedImageFormats()])):
     '''
     :param dir: folder with files
     :param extensions: tuple with file endings. e.g. ('.jpg', '.png'). Files with these endings will be added to img_paths
@@ -129,7 +130,7 @@ def init_ui(self):
         self.next_button.clicked.connect(self.continue_app)
         self.next_button.setObjectName("blueButton")
 
-        # Erro message
+        # Error message
         self.error_message.setGeometry(20, 810, self.width - 20, 20)
         self.error_message.setAlignment(Qt.AlignCenter)
         self.error_message.setStyleSheet('color: red; font-weight: bold')
@@ -211,7 +212,7 @@ def pick_labels_file(self):
             self.numLabelsInput.setText(str(len(labels)))
             self.generate_label_inputs()
 
-            # fill the input fileds with loaded labels
+            # fill the input fields with loaded labels
             for input, label in zip(self.label_inputs, labels):
                 input.setText(label)
 
@@ -250,6 +251,7 @@ def generate_label_inputs(self):
             self.groupBox.setLayout(self.formLayout)
             self.scroll.setWidget(self.groupBox)
             self.scroll.setWidgetResizable(True)
+
     def centerOnScreen(self):
         """
         Centers the window on the screen.
@@ -330,6 +332,7 @@ def __init__(self, labels, input_folder, mode):
         self.curr_image_headline = QLabel('Current image', self)
         self.csv_note = QLabel('(csv will be also generated automatically after closing the app)', self)
         self.csv_generated_message = QLabel(self)
+        self.german_format_check_box = QCheckBox("Save as German format", self)
         self.show_next_checkbox = QCheckBox("Automatically show next image when labeled", self)
         self.generate_xlsx_checkbox = QCheckBox("Also generate .xlsx file", self)
 
@@ -355,6 +358,7 @@ def init_ui(self):
 
         # "create xlsx" checkbox
         self.generate_xlsx_checkbox.setChecked(False)
+        self.german_format_check_box.setGeometry(self.img_panel_width + 140, 560, 300, 20)
         self.generate_xlsx_checkbox.setGeometry(self.img_panel_width + 140, 606, 300, 20)
 
         # image headline
@@ -390,6 +394,8 @@ def init_ui(self):
         ui_line.setGeometry(20, 98, 1012, 1)
         ui_line.setStyleSheet('background-color: black')
 
+        # init checkbox to generate the csv in german format add sep with replacing the delimiter
+
         # apply custom styles
         try:
             styles_path = "./styles.qss"
@@ -474,7 +480,7 @@ def set_label(self, label):
                 elif self.mode == 'move':
                     # label was in assigned labels, so I want to remove it from label folder,
                     # but this was the last label, so move the image to input folder.
-                    # Don't remove it, because it it not save anywehre else
+                    # Don't remove it, because it not save anywhere else
                     if img_name not in self.assigned_labels.keys():
                         shutil.move(os.path.join(self.input_folder, label, img_name), self.input_folder)
                     else:
@@ -601,7 +607,12 @@ def generate_csv(self, out_filename):
         csv_file_path = os.path.join(path_to_save, out_filename) + '.csv'
 
         with open(csv_file_path, "w", newline='') as csv_file:
-            writer = csv.writer(csv_file, delimiter=',')
+            if(self.german_format_check_box.isChecked()):
+                delimiter = ';'
+            else:
+                delimiter = ','
+
+            writer = csv.writer(csv_file, delimiter=delimiter)
 
             # write header
             writer.writerow(['img'] + self.labels)
@@ -640,7 +651,7 @@ def csv_to_xlsx(self, csv_file_path):
     def set_button_color(self, filename):
         """
         changes color of button which corresponds to selected label
-        :filename filename of loaded image:
+        :filename of loaded image:
         """
 
         if filename in self.assigned_labels.keys():
diff --git a/test/.gitkeep b/test/.gitkeep
new file mode 100644
index 0000000..e69de29
diff --git a/test/test_generate_csv.py b/test/test_generate_csv.py
new file mode 100644
index 0000000..3b70cc8
--- /dev/null
+++ b/test/test_generate_csv.py
@@ -0,0 +1,51 @@
+import pytest
+from PyQt5.QtWidgets import QApplication
+from app.main import LabelerWindow
+
+@pytest.fixture
+def app(qtbot):
+    test_app = LabelerWindow(labels=['landschaft', 'menschen'], input_folder='test_folder', mode='csv')
+    qtbot.addWidget(test_app)
+    return test_app
+
+def test_generate_csv_german(app, qtbot, tmpdir):
+    # Set up the environment for the test
+    app.german_format_check_box.setChecked(True)
+    app.assigned_labels = {
+        'test1.jpg': ['landschaft'],
+        'test2.BMP': ['landschaft'],
+        'test3.jpg': ['menschen'],
+        'test4.gif': ['menschen']
+    }
+    output_csv = "test_output"
+    app.generate_csv(output_csv)
+
+    with open(r"test_folder/output/" + output_csv + ".csv") as f:
+        lines = f.readlines()
+
+    assert lines[0].strip() == 'img;landschaft;menschen'
+    assert lines[1].strip() == 'test1.jpg;1;0'
+    assert lines[2].strip() == 'test2.BMP;1;0'
+    assert lines[3].strip() == 'test3.jpg;0;1'
+    assert lines[4].strip() == 'test4.gif;0;1'
+
+def test_generate_csv_no_german_format(app, qtbot, tmpdir):
+    # Set up the environment for the test
+    app.german_format_check_box.setChecked(False)
+    app.assigned_labels = {
+        'test1.jpg': ['landschaft'],
+        'test2.BMP': ['landschaft'],
+        'test3.jpg': ['menschen'],
+        'test4.gif': ['menschen']
+    }
+    output_csv = "test_output"
+    app.generate_csv(output_csv)
+
+    with open(r"test_folder/output/" + output_csv + ".csv") as f:
+        lines = f.readlines()
+
+    assert lines[0].strip() == 'img,landschaft,menschen'
+    assert lines[1].strip() == 'test1.jpg,1,0'
+    assert lines[2].strip() == 'test2.BMP,1,0'
+    assert lines[3].strip() == 'test3.jpg,0,1'
+    assert lines[4].strip() == 'test4.gif,0,1'
\ No newline at end of file
diff --git a/test/test_img_paths.py b/test/test_img_paths.py
new file mode 100644
index 0000000..96a10d0
--- /dev/null
+++ b/test/test_img_paths.py
@@ -0,0 +1,38 @@
+import os
+import pytest
+from app.main import get_img_paths
+from PyQt5.QtGui import QImageReader
+
+def test_supported_image_formats(tmpdir):
+    # Get supported image formats from QImageReader
+    # This will return a tuple of which represent the supported image file extensions (e.g., '.jpg', '.png')
+    expected_formats = tuple('.' + extension.data().decode('utf-8') for extension in QImageReader.supportedImageFormats())
+    
+    # Create a temporary directory with dummy image files of each supported format
+    # Using the tmpdir fixture from pytest to create a temporary directory that will be automatically cleaned up
+    for fmt in expected_formats:
+        # Construct the file path for a dummy image file with the given format
+        file_path = os.path.join(tmpdir, f'test_image{fmt}')
+        # Create an empty file with the specified format
+        open(file_path, 'a').close()
+    
+    # Get image paths using the updated get_img_paths function
+    # This function should return a list of paths to the image files in the directory that match the supported formats
+    img_paths = get_img_paths(tmpdir)
+    
+    # Ensure all supported image formats are detected
+    # The number of detected image paths should match the number of supported formats
+    assert len(img_paths) == len(expected_formats)
+    # Verify that each detected image path has an extension that is in the expected formats
+    for path in img_paths:
+        assert os.path.splitext(path)[1] in expected_formats
+
+def test_no_images_found(tmpdir):
+    # Create a temporary directory with no image files
+    # Using the tmpdir fixture from pytest to create a temporary directory
+    # This time, we do not create any image files in the directory
+    img_paths = get_img_paths(tmpdir)
+    
+    # Ensure no images are found
+    # Since no image files were created in the directory, get_img_paths should return an empty list
+    assert img_paths == []
\ No newline at end of file
diff --git a/test_folder/.gitkeep b/test_folder/.gitkeep
new file mode 100644
index 0000000..e69de29
diff --git a/test_folder/test1.jpg b/test_folder/test1.jpg
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index 0000000..f04940e
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diff --git a/test_folder/test2.BMP b/test_folder/test2.BMP
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index 0000000..3ba9f4a
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diff --git a/test_folder/test3.jpg b/test_folder/test3.jpg
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index 0000000..54b4dca
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diff --git a/test_folder/test4.gif b/test_folder/test4.gif
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index 0000000..074d234
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