Add a trackbar which allows user to define the number of pixels

which make up an area of interest for evaluation for us.

oi-sensor/oi-sensor.py

@@ -27,6 +27,7 @@ DEFAULT_LV = (0, 255,)
 DEFAULT_UH = (135, 180,)
 DEFAULT_US = (190, 255,)
 DEFAULT_UV = (190, 255,)
+DEFAULT_AREA = (400, 1000,)
 
 # command line handling
 parser = argparse.ArgumentParser(description='Run optical inspection OPC UA server.')
@@ -73,6 +74,7 @@ async def main():
         cv2.createTrackbar("U-H", "Trackbars", DEFAULT_UH[0], DEFAULT_UH[1], nothing)
         cv2.createTrackbar("U-S", "Trackbars", DEFAULT_US[0], DEFAULT_US[1], nothing)
         cv2.createTrackbar("U-V", "Trackbars", DEFAULT_UV[0], DEFAULT_UV[1], nothing)
+        cv2.createTrackbar("Area", "Trackbars", DEFAULT_AREA[0], DEFAULT_AREA[1], nothing)
 
     _logger.info("Starting server!")
     async with server:
@@ -92,6 +94,7 @@ async def main():
                 u_h = cv2.getTrackbarPos("U-H", "Trackbars")
                 u_s = cv2.getTrackbarPos("U-S", "Trackbars")
                 u_v = cv2.getTrackbarPos("U-V", "Trackbars")
+                designated_area = cv2.getTrackbarPos("Area", "Trackbars")
             else:
                 # read defaults provided
                 l_h = DEFAULT_LH[0]
@@ -100,6 +103,7 @@ async def main():
                 u_h = DEFAULT_UH[0]
                 u_s = DEFAULT_US[0]
                 u_v = DEFAULT_UV[0]
+                designated_area = DEFAULT_AREA[0]
 
             lower_red = np.array([l_h, l_s, l_v])
             upper_red = np.array([u_h, u_s, u_v])
@@ -117,7 +121,7 @@ async def main():
                 x = approx.ravel()[0]
                 y = approx.ravel()[1]
 
-                if area > 400:
+                if area > designated_area:
                     cv2.drawContours(frame, [approx], 0, (0, 0, 0), 5)
                     number_of_points = len(approx)
                     if number_of_points == 3: