Add support for inverted-color QR codes

Author: tadeubas

seedqreader.py

@@ -56,6 +56,8 @@
 FORMAT_SPECTER = 'Specter'
 FORMAT_BBQR = 'BBQR'
 
+PYZBAR_SYMBOLS = (pyzbar.ZBarSymbol.QRCODE, pyzbar.ZBarSymbol.SQCODE)
+
 # helper obj to handle bbqr encoding and file_type
 bbqr_obj = None
 
@@ -596,8 +598,14 @@ def run(self):
                 # Set the pixmap to the label
                 self.video_stream.emit(scaled_pixmap)
 
-                data = pyzbar.decode(frame)
+                data = pyzbar.decode(frame, PYZBAR_SYMBOLS)
                 str_data = ""
+
+                # Try to invert colors
+                if not data:
+                    frame = cv2.bitwise_not(frame)
+                    data = pyzbar.decode(frame, PYZBAR_SYMBOLS)
+
                 if data:
                     # print("try to_str(data[0].data)", data)
                     try: