From 77a6d19c3b9e3c0899296a6af9a6248200db0087 Mon Sep 17 00:00:00 2001
From: Edgar O Silva <oswaldo.silva@gmail.com>
Date: Fri, 10 Jan 2014 15:59:29 -0600
Subject: [PATCH 1/2] Reading less frames per second avoids the issue of
 multiple faces detected when only one exists due to the same frame being
 updated while image detection processing is executed.

---
 examples/coffeescript/camera-face-detection.coffee | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/examples/coffeescript/camera-face-detection.coffee b/examples/coffeescript/camera-face-detection.coffee
index fb41f90..07da68d 100644
--- a/examples/coffeescript/camera-face-detection.coffee
+++ b/examples/coffeescript/camera-face-detection.coffee
@@ -41,9 +41,9 @@ intervalId = setInterval(()->
 
     # Finally we get the key pressed on the window to terminate
     # execution of the program.
-    res = namedWindow.blockingWaitKey(0, 20)
+    res = namedWindow.blockingWaitKey(0, 50)
 
     # In this case I terminate the program if any key is pressed.
     if res >= 0 then clearInterval(intervalId)
   )
-, 50)
+, 150)

From 1c96622c6728fb373d0a7b272ea4318f666f4fa5 Mon Sep 17 00:00:00 2001
From: Edgar O Silva <oswaldo.silva@gmail.com>
Date: Fri, 10 Jan 2014 16:01:01 -0600
Subject: [PATCH 2/2] Use recursinve frame reading (instead of time interval)
 from video feed to try and hit max frames per second.

---
 .../camera-face-detect-max-frames.coffee      | 56 +++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 examples/coffeescript/camera-face-detect-max-frames.coffee

diff --git a/examples/coffeescript/camera-face-detect-max-frames.coffee b/examples/coffeescript/camera-face-detect-max-frames.coffee
new file mode 100644
index 0000000..5e6eee7
--- /dev/null
+++ b/examples/coffeescript/camera-face-detect-max-frames.coffee
@@ -0,0 +1,56 @@
+cv = require 'opencv'
+
+# First we create a new VideoCapture object to get
+# video from the camera (0 for default camera)
+camera = new cv.VideoCapture(1)
+
+# we create a window to display the Video frames
+namedWindow = new cv.NamedWindow('Video', 0)
+color = [255,0,0]
+
+frameRead = () ->
+  # camera.read allows us to retrieve the current
+  # frame to be displayed in the video window.
+  camera.read((err, im) ->
+    # We can check for errors and even break the
+    # program execution if an error is detected here.
+    console.log "The err ==>#{ err }" if err
+
+    # There is no need to display the image width or Height
+    # but I leave this here in case anyone needs to check them.
+    #console.log("Width: #{im.width()}")
+    #console.log("height: #{im.height()}")
+
+    # Before working with the frame we need to check the image
+    # is already available and has a width and height greater than 0,
+    # otherwise it will fail when trying to do namedWindow.show()
+    # and the image has width or height equal or less than 0.
+    if im.width() > 0 and im.height() > 0
+      #console.log("Interval ID => #{ intervalId }")
+      #console.log(intervalId)
+      clearInterval(intervalId) if intervalId?
+      im.detectObject('./haarcascades/haarcascade_frontalface_alt.xml', {}, (err, faces) ->
+        for face in faces
+          im.rectangle([face.x, face.y], [face.x + face.width, face.y + face.height], [0,255,0], 2)
+
+        # We use the previously created namedWindow to display the
+        # video frame to wich we applied the blur and filter.
+        namedWindow.show(im)
+
+        # Finally we get the key pressed on the window to terminate
+        # execution of the program.
+        res = namedWindow.blockingWaitKey(0, 20)
+
+        # In this case we terminate the program if any key is pressed.
+        #if res >= 0 then do not set a new timeout to get a new frame.
+        setTimeout(frameRead, 5) if res < 0
+      )
+
+  )
+
+# We set an interval to retrieve frames from the
+# video source and we get the intervalId so we can
+# stop the program by pressing any key on the video feed window.
+intervalId = setInterval(() ->
+  frameRead(intervalId)
+, 100)