Implement some optimization in shape detection.

oi-sensor/oi-sensor.py

@@ -19,6 +19,7 @@ from asyncua import Server
 import argparse
 import time
 
+
 SLEEP_DURATION = 10e-3 # 10 milliseconds
 
 # algorith defaults
@@ -39,6 +40,8 @@ a('--ipv4', help='The IPv4 address on which the OPC UA server runs', default="0.
 a('--port', help='The port on which the OPC UA server runs', default="4840")
 a('--camera', help='The index of the camera (i.e. indxed in /dev/videoX)', default=0)
 a('--headless', help='Run without screen in a headless mode (boolean, default=0)', default=False)
+# XXX: allow to specify from CLI DEFAULT_LH & friends
+
 args = parser.parse_args()
 ipv4 = args.ipv4
 port = args.port
@@ -65,6 +68,10 @@ async def main():
     myvar = await myobj.add_variable(idx, "shape", 0.0)
     await myvar.set_writable()
 
+    # Initialize
+    result_stack = []
+    current_shape = 0.0
+
     # init camera
     cap = cv2.VideoCapture(camera)
     font = cv2.FONT_HERSHEY_COMPLEX
@@ -149,8 +156,22 @@ async def main():
                         result = 0.0
                     # printout
                     print("\tDetected area (px)=%.2f, result=%d" %(area, result))
+
+                    # update list for last X results (FILO)
+                    default_occurence_number = 5
+                    result_stack.append(result)
+                    if len(result_stack) > default_occurence_number:
+                        # leave only last X items
+                        result_stack = result_stack[-default_occurence_number:]
+
+                    # to avoid sometimes errors in detection algorithm we change OPC UA node
+                    # variable only if at least we have 40% (2) of last 5 items detected as this
+                    # shape. Not complex but avoid false results.
+                    count = result_stack.count(result)
+                    if count >= 2:
                         # update OPC UA server's node attribute
-                    await myvar.write_value(0.0)
+                        current_shape = result
+                        await myvar.write_value(result)
 
             # show current MASK and camera output windows
             if not headless: