Initial commit

This is the first working version

Camera_latency_fps_measure.py

@@ -0,0 +1,67 @@
+# -*- coding: utf-8 -*-
+"""
+This utility measures the latency and frame rate for a 
+USB webcam.  The preview window shows the timestamps to indicate latency
+(you will need to point the camera at the monitor), and the console will
+print out the frame per second. 
+
+You may need to edit the camera channel, width, height, 
+
+Created on Mon Feb 08 23:00:39 2016
+
+@author: perrytsao 
+More info at www.makehardware.com/webcam-latency
+
+"""
+import timeit
+import time
+import cv2
+
+###############################################
+width=640
+height=480
+fps=15
+camera_channel=1
+fname="camera_latency"
+###############################################
+wait_time=1
+
+cv2.namedWindow("preview")
+vc = cv2.VideoCapture(camera_channel)
+vc.set(cv2.CAP_PROP_FRAME_WIDTH,width)
+vc.set(cv2.CAP_PROP_FRAME_HEIGHT,height)
+vc.set(cv2.CAP_PROP_FPS,fps) 
+
+################################################
+time.sleep(2)
+font = cv2.FONT_HERSHEY_SIMPLEX
+try: 
+    if vc.isOpened(): # try to get the first frame
+        rval, frame_o = vc.read()
+
+    else:
+        rval = False
+    ii=100
+    toc=0    
+    tic=timeit.default_timer()
+    while rval:
+        toc_old=toc
+        toc=timeit.default_timer()        
+        delta=toc-toc_old
+        print("delta: %0.3f  fps: %0.3f" % (delta, 1/delta))
+        cv2.putText(frame_o, "%0.3f" % (toc-tic), (50,200), font, 2, (255,255,255),4,cv2.LINE_AA)       
+        cv2.imshow("preview", frame_o)
+        key = cv2.waitKey(wait_time)
+
+        ## Monitor keyboard
+        if key == 27: # exit on ESC
+            break
+        elif key == 32:
+            cv2.imwrite(fname+str(ii)+".jpg", frame_o)
+            ii+=1
+        rval, frame_o = vc.read()
+
+finally: 
+    vc.release()
+    cv2.destroyAllWindows()
+