Add another CLI mode which allows to run oi-sensor in environment

where a X11 server is NOT available.

oi-sensor/oi-sensor.py

@@ -20,16 +20,26 @@ import argparse
 
 SLEEP_DURATION = 10e-3 # 10 milliseconds
 
+# algorith defaults
+DEFAULT_LH = (0, 180,)
+DEFAULT_LS = (0, 255,)
+DEFAULT_LV = (0, 255,)
+DEFAULT_UH = (135, 180,)
+DEFAULT_US = (190, 255,)
+DEFAULT_UV = (190, 255,)
+
 # command line handling
 parser = argparse.ArgumentParser(description='Run optical inspection OPC UA server.')
 a = parser.add_argument
 a('--ipv4', help='The IPv4 address on which the OPC UA server runs', default="0.0.0.0")
 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)
 args = parser.parse_args()
 ipv4 = args.ipv4
 port = args.port
 camera = int(args.camera)
+headless = bool(int(args.headless))
 
 def nothing(x):
     # any operation
@@ -53,14 +63,16 @@ async def main():
 
     # init camera
     cap = cv2.VideoCapture(camera)
-    cv2.namedWindow("Trackbars")
-    cv2.createTrackbar("L-H", "Trackbars", 0, 180, nothing)
-    cv2.createTrackbar("L-S", "Trackbars", 0, 255, nothing)
-    cv2.createTrackbar("L-V", "Trackbars", 0, 255, nothing)
-    cv2.createTrackbar("U-H", "Trackbars", 135, 180, nothing)
-    cv2.createTrackbar("U-S", "Trackbars", 190, 255, nothing)
-    cv2.createTrackbar("U-V", "Trackbars", 190, 255, nothing)
     font = cv2.FONT_HERSHEY_COMPLEX
+    if not headless:
+        # create UI
+        cv2.namedWindow("Trackbars")
+        cv2.createTrackbar("L-H", "Trackbars", DEFAULT_LH[0], DEFAULT_LH[1], nothing)
+        cv2.createTrackbar("L-S", "Trackbars", DEFAULT_LS[0], DEFAULT_LS[1], nothing)
+        cv2.createTrackbar("L-V", "Trackbars", DEFAULT_LV[0], DEFAULT_LV[1], nothing)
+        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)
 
     _logger.info("Starting server!")
     async with server:
@@ -73,12 +85,22 @@ async def main():
             # read and process camera 
             _, frame = cap.read()
             hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)
-            l_h = cv2.getTrackbarPos("L-H", "Trackbars")
-            l_s = cv2.getTrackbarPos("L-S", "Trackbars")
-            l_v = cv2.getTrackbarPos("L-V", "Trackbars")
-            u_h = cv2.getTrackbarPos("U-H", "Trackbars")
-            u_s = cv2.getTrackbarPos("U-S", "Trackbars")
-            u_v = cv2.getTrackbarPos("U-V", "Trackbars")
+            if not headless:
+                l_h = cv2.getTrackbarPos("L-H", "Trackbars")
+                l_s = cv2.getTrackbarPos("L-S", "Trackbars")
+                l_v = cv2.getTrackbarPos("L-V", "Trackbars")
+                u_h = cv2.getTrackbarPos("U-H", "Trackbars")
+                u_s = cv2.getTrackbarPos("U-S", "Trackbars")
+                u_v = cv2.getTrackbarPos("U-V", "Trackbars")
+            else:
+                # read defaults provided
+                l_h = DEFAULT_LH[0]
+                l_s = DEFAULT_LS[0]
+                l_v = DEFAULT_LV[0]
+                u_h = DEFAULT_UH[0]
+                u_s = DEFAULT_US[0]
+                u_v = DEFAULT_UV[0]
+
             lower_red = np.array([l_h, l_s, l_v])
             upper_red = np.array([u_h, u_s, u_v])
 
@@ -110,8 +132,10 @@ async def main():
                     else:
                         await myvar.write_value(0.0)
 
-            cv2.imshow("Frame", frame)
-            cv2.imshow("Mask", mask)
+            # show current MASK and camera output windows
+            if not headless:
+                cv2.imshow("Frame", frame)
+                cv2.imshow("Mask", mask)
 
             key = cv2.waitKey(1)
             if key == 27: