Electronics

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Make A Snapchat lens for your webcam?

Ever use a Snapchat lens and just wonder “How’d they do that?”. Well, even if not, I’m going to take a look at some of the face tracking and computer vision technologies that ma...
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DIY Retro Style Digital Camera

Cameras have been around for centuries. But since the birth of digital, many of the old film cameras have just been tossed aside. Let’s give these amazing pieces of technology a second chance by ...

Step 1

Install Software

In order to track faces using a webcam on the Raspberry Pi, you need to install “Computer Vision” software. There’s an easy to use python-based software called “SimpleCV” that is free to install on Windows, Mac and Linux. My instructions below are for how to install it on a Raspberry Pi.

sudo apt-get update

sudo apt-get upgrade

sudo apt-get install ipython python-opencv python-scipy

sudo pip install https://github.com/sightmachine/SimpleCV/zipball/master

sudo pip install pyparsing svgwrite

sudo modprobe bcm2835-v4l2

Step 2

Writing The Program



Here’s some sample python code that I used to track a mustache onto faces that the webcam recognizes:

#!/usr/bin/python

from SimpleCV import *
display = Display()
cam = Camera()
mustache = Image("stache4.png")
mask = mustache.hueDistance(color=Color.GREEN).binarize()
result = (mask.invert() - mustache)

face_cascade = HaarCascade("face.xml")
nose_cascade = HaarCascade("nose.xml")

while display.isNotDone():
 image = cam.getImage().flipHorizontal()
 faces = image.findHaarFeatures(face_cascade)
 if faces:
 faces = faces.sortArea()
 face = faces[-1]
 myFace = face.crop()
 noses = myFace.findHaarFeatures(nose_cascade)
 if noses:
 noses = noses.sortArea()
 nose = noses[0]
 xf = face.x - (face.width()/2)
 yf = face.y - (face.height()/2)
 xm = nose.x - (nose.width()/2)
 ym = nose.y - (nose.width()/2)

xstache = xf+xm-(mustache.width/2)+(nose.width()/2)
 ystache = yf+ym+(2*nose.height()/3)
 image = image.blit(mustache,pos=(xstache,ystache), mask=mask.invert())
 image.show()