Video feed with face detection example.

examples/coffeescript/camera-face-detection.coffee

@@ -0,0 +1,67 @@
+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',1)
+color = [255,0,0]
+
+# We set an interval to retrieve frames from the
+# video source and we get the intervalId so we can
+# stop the program from the video feed window.
+intervalId = setInterval(()->
+
+  # 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
+      # We apply filters and effects to the frame we got from the
+      # camera to manipulate the video that we'll display.
+      # First we convert to grayscale.
+      #im.convertGrayscale()
+      # We then apply GaussianBlur.
+      # It takes an array of type double and size 2
+      # that indicates how strong the gaussian blur should be.
+      im.gaussianBlur([7,7])
+      # We then apply canny edge filtering.
+      # Params are lower and higher threshold and aperture size,
+      # although nodejs-opencv overwrite the aperture size param
+      # with 0. An update to consider it is needed.
+      #im.canny(0, 30, 3)
+      #gray = new cv.Matrix(src1.width(), src2.height())
+      #gray = im.copy()
+      #gray.convertGrayscale()
+
+      im.detectObject('./haarcascades/haarcascade_frontalface_alt.xml', {}, (err, faces) ->
+        console.log("Faces length => #{ faces }")
+        for face in faces
+          im.rectangle([face.x, face.y], [face.x + face.width, face.y + face.height], [0,255,0], 2)
+
+        namedWindow.show(im)
+      )
+      # We use the previously created namedWindow to display the
+      # video frame to wich we applied the blur and filter.
+
+    # Finally we get the key pressed on the window to terminate
+    # execution of the program.
+    res = namedWindow.blockingWaitKey(0, 20)
+
+    # In this case I terminate the program if any key is pressed.
+    if res >= 0 then clearInterval(intervalId)
+  )
+, 50)

examples/coffeescript/image-basic-shapes.coffee

@@ -0,0 +1,29 @@
+cv = require('opencv')
+
+
+cv.readImage("./images/mona.png", (err, im) ->
+  # Create new NamedWindow object to hold the image
+  # NamedWindow takes two arguments String WindowName and String windowSize
+  namedWindow = new cv.NamedWindow('Display Window', '400x400')
+
+  # We add a couple of basic shapes to the image, just to show how
+  # to create basic shapes.
+  # im.rectangle([startX, StartY], [width, height], color(array of RGB)
+  im.rectangle([50, 50], [200, 200], [0, 255, 0], 2)
+  # im.ellipse(centerX, centerY, width, height, color(array of RGB)
+  im.ellipse(150, 150, 50, 50, [255, 255, 0], 2)
+
+  # We then tell the image to show the image we loaded.
+  namedWindow.show(im)
+
+  console.log("Image should be displayed inside a window.")
+  # Finally we tell the NamedWindow to wait for any key being pressed to close
+  # itself (by passing a 0 as the first param, or wait a defined amount of time
+  # by passing the time as a second argument (in milliseconds)
+  #
+  # If we do not tell the window to wait it will just load and show the image
+  # and close so fast that it will appear nothing happened.
+  namedWindow.blockingWaitKey(0, 5000)
+
+  console.log("And the window should close automatically or by pressing any key on it.")
+)