Commented most relevant files for submission

face_recognition/app/app.py

@@ -11,6 +11,7 @@ import cv2
 import numpy as np
 import imutils
 app = Flask(__name__)
+#establish connection to minio for this instance of the api
 minioClient = Minio('minio:9000', access_key=os.environ['s3-name'], secret_key=os.environ['s3-password'], secure=False)
  
 @app.route('/')
@@ -27,25 +28,29 @@ def access_minio():
 def new_user_id():
 #save demo object to reserve id in minio
     id = None
+    #five tries to generate unique id
     for limited_try in range(0,5):
         id = str(uuid.uuid4())
         if check_id(id) == False:
             break
     demo_object = ['test']
+    #dump demo object and save it like its a face encoding to reserve id
     with open('/tmp/demo_object.pkl', 'wb') as f:
         pickle.dump(demo_object, f)
     minioClient.fput_object('users', str(id), '/tmp/demo_object.pkl')
     return jsonify({'id':id})
   
 @app.route('/init_face')
-#call like https://face.sguba.de/init_face?id=123&encoded_string=abc
+#call like https://face.sguba.de/init_face?id=123&encoded_string=base64encoded_urlsafe_string
 def new_face():
     id  = request.args.get('id', None)
     img = request.args.get('encoded_string', None)
     temporary_img_path = '/tmp/'+str(id)+'.jpg'
     temporary_pkl_path = '/tmp/'+str(id)+'.pkl'
+    #transcode base64_string to img and generate encoding
     save_img(img, temporary_img_path)
     face_encoding_response = encode_face(temporary_img_path)
+    #check if encoding was successfull, if yes save encoding in minio
     if face_encoding_response['success']==True:
     	with open(temporary_pkl_path, 'wb') as file:
         	pickle.dump(face_encoding_response['encoding'], file)
@@ -59,8 +64,10 @@ def check_face():
     img = request.args.get('encoded_string', None)
     temporary_img_path = '/tmp/'+str(id)+'.jpg'
     temporary_pkl_path = '/tmp/'+str(id)+'.pkl'
+    #transcode base64_string to img and generate encoding
     save_img(img, temporary_img_path)
     face_encoding_response = encode_face(temporary_img_path)
+    #check if encoding was successfull, if yes get initial encoding from minio and compare encodings
     if face_encoding_response['success']==True:
         minioClient.fget_object('users', str(id), temporary_pkl_path)
         with open(temporary_pkl_path, 'rb') as file:
@@ -84,7 +91,9 @@ def check_id(id):
     return known
 
 def save_img(encoded_data, filename):
+    #length of base64 string is always a multiple of 4, if not its padded with =, here we add padding that might have been lost so there are no errors when decoding the img
     encoded_data += "=" * ((4 - len(encoded_data) % 4) % 4)
+    #convert string to binary, decode base64, decode image and rotate it 90 degree because android studio rotates the camera, then save image to temp
     encoded_data = bytes(encoded_data, encoding='utf-8')
     nparr = np.fromstring(base64.urlsafe_b64decode(encoded_data), np.uint8)
     img = cv2.imdecode(nparr, cv2.IMREAD_ANYCOLOR)
@@ -92,18 +101,18 @@ def save_img(encoded_data, filename):
     return cv2.imwrite(filename, img)
   
 def encode_face(path):
+    #create face encoding from data, and check wether it was succesfull. If it was unsuccesfull the encodings list is empty
     success = None
     face = face_recognition.load_image_file(path)
     face_encoding = face_recognition.face_encodings(face)
     if len(face_encoding)==0:
-        success = False
-        response = {'success':success, 'encoding':None}
+        response = {'success':False, 'encoding':None}
     else:
-        success = True
-        response = {'success':success, 'encoding':face_encoding[0]}
+        response = {'success':True, 'encoding':face_encoding[0]}
     return response
           
 def setup():
+    #create minio buckets that are used at startup if they dont exist already
     try:
         minioClient.make_bucket("users")
     except BucketAlreadyOwnedByYou as err:
@@ -113,7 +122,8 @@ def setup():
     except ResponseError as err:
         raise
   
- 
+ #check if the script is run primarily and not imported etc.
 if __name__ == '__main__':
     setup()
+    #start running the api
     app.run(host='0.0.0.0')