add barcode scanner tutorial

Author: x4nth055

README.md

@@ -50,6 +50,7 @@ This is a repository of all the tutorials of [The Python Code](https://www.thepy
         - [How to Blur Faces in Images using OpenCV in Python](https://www.thepythoncode.com/article/blur-faces-in-images-using-opencv-in-python). ([code](machine-learning/blur-faces))
         - [Skin Cancer Detection using TensorFlow in Python](https://www.thepythoncode.com/article/skin-cancer-detection-using-tensorflow-in-python). ([code](machine-learning/skin-cancer-detection))
         - [How to Perform Malaria Cells Classification using TensorFlow 2 and Keras in Python](https://www.thepythoncode.com/article/malaria-cells-classification). ([code](machine-learning/malaria-classification))
+        - [How to Make a Barcode Reader in Python](https://www.thepythoncode.com/article/making-a-barcode-scanner-in-python). ([code](general/barcode-reader))
     - [Building a Speech Emotion Recognizer using Scikit-learn](https://www.thepythoncode.com/article/building-a-speech-emotion-recognizer-using-sklearn). ([code](machine-learning/speech-emotion-recognition))
     - [How to Convert Speech to Text in Python](https://www.thepythoncode.com/article/using-speech-recognition-to-convert-speech-to-text-python). ([code](machine-learning/speech-recognition))
     - [Top 8 Python Libraries For Data Scientists and Machine Learning Engineers](https://www.thepythoncode.com/article/top-python-libraries-for-data-scientists).

general/barcode-reader/README.md

@@ -0,0 +1,11 @@
+# [How to Make a Barcode Reader in Python](https://www.thepythoncode.com/article/making-a-barcode-scanner-in-python)
+To run this:
+- `pip3 install -r requirements.txt`
+- To detect barcodes of the images in this directory:
+    ```
+    python barcode_reader.py
+    ```
+- To detect barcodes live using your camera:
+    ```
+    python live_barcode_reader.py
+    ```

general/barcode-reader/barcode1.png

@@ -0,0 +1,44 @@
+from pyzbar import pyzbar
+import cv2
+
+
+def decode(image):
+    # decodes all barcodes from an image
+    decoded_objects = pyzbar.decode(image)
+    for obj in decoded_objects:
+        # draw the barcode
+        print("detected barcode:", obj)
+        image = draw_barcode(obj, image)
+        # print barcode type & data
+        print("Type:", obj.type)
+        print("Data:", obj.data)
+        print()
+
+    return image
+
+
+def draw_barcode(decoded, image):
+    # n_points = len(decoded.polygon)
+    # for i in range(n_points):
+    #     image = cv2.line(image, decoded.polygon[i], decoded.polygon[(i+1) % n_points], color=(0, 255, 0), thickness=5)
+    # uncomment above and comment below if you want to draw a polygon and not a rectangle
+    image = cv2.rectangle(image, (decoded.rect.left, decoded.rect.top), 
+                            (decoded.rect.left + decoded.rect.width, decoded.rect.top + decoded.rect.height),
+                            color=(0, 255, 0),
+                            thickness=5)
+    return image
+
+
+if __name__ == "__main__":
+    from glob import glob
+
+    barcodes = glob("barcode*.png")
+    for barcode_file in barcodes:
+        # load the image to opencv
+        img = cv2.imread(barcode_file)
+        # decode detected barcodes & get the image
+        # that is drawn
+        img = decode(img)
+        # show the image
+        cv2.imshow("img", img)
+        cv2.waitKey(0)

general/barcode-reader/barcode2.png

@@ -0,0 +1,40 @@
+from pyzbar import pyzbar
+import cv2
+
+
+def draw_barcode(decoded, image):
+    # n_points = len(decoded.polygon)
+    # for i in range(n_points):
+    #     image = cv2.line(image, decoded.polygon[i], decoded.polygon[(i+1) % n_points], color=(0, 255, 0), thickness=5)
+    image = cv2.rectangle(image, (decoded.rect.left, decoded.rect.top), 
+                            (decoded.rect.left + decoded.rect.width, decoded.rect.top + decoded.rect.height),
+                            color=(0, 255, 0),
+                            thickness=5)
+    return image
+
+def decode(image):
+    # decodes all barcodes from an image
+    decoded_objects = pyzbar.decode(image)
+    for obj in decoded_objects:
+        # draw the barcode
+        image = draw_barcode(obj, image)
+        # print barcode type & data
+        print("Type:", obj.type)
+        print("Data:", obj.data)
+        print()
+
+    return image
+
+
+if __name__ == "__main__":
+    cap = cv2.VideoCapture(0)
+    while True:
+        # read the frame from the camera
+        _, frame = cap.read()
+        # decode detected barcodes & get the image
+        # that is drawn
+        frame, decoded_objects = decode(frame)
+        # show the image in the window
+        cv2.imshow("frame", frame)
+        if cv2.waitKey(1) == ord("q"):
+            break

general/barcode-reader/barcode3.png

@@ -0,0 +1,2 @@
+opencv-python
+pyzbar