improved code structure

main.py

@@ -2,68 +2,86 @@
 
 import cv2
 import os
-from os import path
 import time
 from datetime import datetime
 
 # Opencv DNN
 net = cv2.dnn.readNet("dnn_model/yolov4-tiny.weights", "dnn_model/yolov4-tiny.cfg")
 model = cv2.dnn_DetectionModel(net)
-model.setInputParams(size=(320, 320), scale=1/255)
+model.setInputParams(size=(320, 320), scale=1 / 255)
 
 # Load Class list
 classes = []
+
 with open("dnn_model/classes.txt", "r") as f:
     for class_name in f.readlines():
         class_name = class_name.strip()
         classes.append(class_name)
 
-#print("Objects list")
-#print("classes")
-
 # Initialize camera
 cap = cv2.VideoCapture(0)
 cap.set(cv2.CAP_PROP_FRAME_WIDTH, 1280)
 cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 720)
 
-start_time = time.time()
-
 # Configurations
-thres = 0.25        # confidence threshold
-timeInterval = 5    # timeinterval for capturing
-capture = True      # capture if True
+thres = os.getenv("THRES",0.25)        # confidence threshold
+timeInterval = os.getenv("TIMEINT",5)    # time interval for capturing
+capture = os.getenv("CAPTURE",True)      # capture if True
 folder = "images/"  # path to store images
 
-if not os.path.exists(folder):
-    os.mkdir(folder)
 
-# Font/Box style used for labelling object detected
-font = cv2.FONT_HERSHEY_PLAIN
-font_scale = 1
-thick = 2
+# Object Detection
+def objdetect(frame, thres):
+    (class_ids, scores, bboxes) = model.detect(
+            frame, confThreshold=thres, nmsThreshold=0.4
+    )
+    for class_id, score, bbox in zip(class_ids, scores, bboxes):
+        (x, y, w, h) = bbox
+        class_name = classes[class_id]
+
+        cv2.putText(
+            frame,
+            class_name.capitalize(),
+            (x, y - 10),
+            cv2.FONT_HERSHEY_PLAIN,
+            fontScale=1,
+            color=(0, 200, 50),
+            thickness=2,
+        )
 
-while True:
-    if cap.isOpened():
-        # Get Frames
-        ret, frame = cap.read()
-        if ret:
-            # Object Detection
-            (class_ids, scores, bboxes) = model.detect(frame, confThreshold = thres, nmsThreshold=.4)
-            for class_id, score, bbox in zip(class_ids, scores, bboxes):
-                (x, y, w, h) = bbox
-                class_name = classes[class_id]
+        cv2.rectangle(
+            frame,
+            (x, y),
+            (x + w, y + h),
+            color=(0, 200, 50),
+            thickness=2,
+        )
 
-                cv2.putText(frame, class_name.capitalize(), (x,y - 10), font, font_scale, (0, 200, 50), thick)
-                cv2.rectangle(frame, (x, y), (x + w, y + h), (0, 200, 50), thick)
-            # Uncomment below lines to see real time feed of object detection
-            #cv2.imshow("ObjectDetection", frame)
-            #cv2.waitKey(1)
-            if int(round(time.time()-start_time, 2)) >= timeInterval:
-                filename = "{}.png".format(datetime.now().strftime("%Y-%m-%d_%H-%M-%S"))
-                cv2.imwrite(os.path.join(folder,filename), frame)
-                start_time = time.time()
-        if capture != True:
+
+# cap.isOpened() to check cap object has started capturing the frame.
+while cap.isOpened() and capture:
+    # Get Frames
+    ret, frame = cap.read()
+
+    if ret:
+        # Error Handling
+        try:
+            if not os.path.exists(folder):
+                os.mkdir(folder)
+        except PermissionError as pe:
+            print("Cannot create folder "+str(pe))
             break
+        else:
+            objdetect(frame, thres)
+
+        # Saving images to specified folder.
+        filename = "{}.jpeg".format(datetime.now().strftime("%Y-%m-%d_%H-%M-%S"))
+        cv2.imwrite(os.path.join(folder, filename), frame)
+
+        # Suspend execution for set time interval.
+        time.sleep(timeInterval)
+    else:
+        break
 
 cap.release()
 cv2.destroyAllWindows()