Update rc_driver.py

Add threshold checking to determine if traffic light is on

computer/rc_driver.py

@@ -77,6 +77,9 @@ class ObjectDetection(object):
         # y camera coordinate of the target point 'P'
         v = 0
 
+        # minimum value to proceed traffic light state validation
+        threshold = 150     
+        
         # detection
         cascade_obj = cascade_classifier.detectMultiScale(
             gray_image,
@@ -101,22 +104,25 @@ class ObjectDetection(object):
                 roi = gray_image[y_pos+10:y_pos + height-10, x_pos+10:x_pos + width-10]
                 mask = cv2.GaussianBlur(roi, (25, 25), 0)
                 (minVal, maxVal, minLoc, maxLoc) = cv2.minMaxLoc(mask)
-                cv2.circle(roi, maxLoc, 5, (255, 0, 0), 2)
                 
-                # Red light
-                if 1.0/8*(height-30) < maxLoc[1] < 4.0/8*(height-30):
-                    cv2.putText(image, 'Red', (x_pos+5, y_pos-5), cv2.FONT_HERSHEY_SIMPLEX, 0.5, (0, 0, 255), 2)
-                    self.red_light = True
+                # check if light is on
+                if maxVal - minVal > threshold:
+                    cv2.circle(roi, maxLoc, 5, (255, 0, 0), 2)
                     
-                # Green light
-                elif 5.5/8*(height-30) < maxLoc[1] < height-30:
-                    cv2.putText(image, 'Green', (x_pos+5, y_pos - 10), cv2.FONT_HERSHEY_SIMPLEX, 0.5, (0, 255, 0), 2)
-                    self.green_light = True
+                    # Red light
+                    if 1.0/8*(height-30) < maxLoc[1] < 4.0/8*(height-30):
+                        cv2.putText(image, 'Red', (x_pos+5, y_pos-5), cv2.FONT_HERSHEY_SIMPLEX, 0.5, (0, 0, 255), 2)
+                        self.red_light = True
                     
-                # yellow light
-                #elif 4.0/8*(height-30) < maxLoc[1] < 5.5/8*(height-30):
-                #    cv2.putText(image, 'Yellow', (x_pos+5, y_pos - 10), cv2.FONT_HERSHEY_SIMPLEX, 0.5, (0, 255, 255), 2)
-                #    self.yellow_light = True
+                    # Green light
+                    elif 5.5/8*(height-30) < maxLoc[1] < height-30:
+                        cv2.putText(image, 'Green', (x_pos+5, y_pos - 10), cv2.FONT_HERSHEY_SIMPLEX, 0.5, (0, 255, 0), 2)
+                        self.green_light = True
+    
+                    # yellow light
+                    #elif 4.0/8*(height-30) < maxLoc[1] < 5.5/8*(height-30):
+                    #    cv2.putText(image, 'Yellow', (x_pos+5, y_pos - 10), cv2.FONT_HERSHEY_SIMPLEX, 0.5, (0, 255, 255), 2)
+                    #    self.yellow_light = True
         return v