This one is for Real Time detection. It could probably me optimized, but it works!!! This is the first cool thing I've done. It taught me a lot about ctypes, how to use it and how it works. I can't take credit for the actual detection because I am using a DLL from someone else.

This will detect 1 face at least 85% of the time. Other factor such as light, head position, and distance play a role.

Requires:PIL
VideoCapture
Pyscho (could be taken out if needed)
fdlib.dll
Pygame
#Face Detection Real-Time
#supports 1 face detection so far
#http://www.kyb.mpg.de/bs/people/kienzle/facedemo/facedemo.htm
#Tech B.
#3/10/2010

from VideoCapture import Device
from ctypes import *
import Image, ImageDraw, os, time, pygame, sys
from pygame.locals import *
from psyco import full
full()

#add style and clear screen
os.system('color 02')

fd = cdll.LoadLibrary("fdlib.dll") #dll found at http://www.kyb.mpg.de/bs/people/kienzle/facedemo/facedemo.htm


#assignments
cam = Device()
pygame.init()
screen = pygame.display.set_mode((640,480))
pygame.display.set_caption('Facial Recognition')

pixX = 0
pixY = 0
pixList = []

w = c_int(640)
h = c_int(480)
threshold = c_int(0)

x = c_int * 256
y = c_int * 256
size = c_int * 256
x = x()
y = y()
size = size()


graydata = c_ubyte * (640*480)
graydata = graydata()
while 1:

for event in pygame.event.get():
if event.type == pygame.QUIT: sys.exit()
im = cam.getImage()
draw = ImageDraw.Draw(im)
img = im.convert("L")
imd = list(img.getdata())
cnt = 0
pixX = 0
pixY = 0
cnt = 0
for pix in imd:
graydata[cnt] = imd[cnt]
cnt+=1

fd.fdlib_detectfaces(byref(graydata), w, h, threshold)
n = fd.fdlib_getndetections()
if n == 1:
fd.fdlib_getdetection(c_int(0), x, y, size)

bBoxTres = size[0]/2
draw.rectangle([(x[0]+bBoxTres,y[0]+bBoxTres),(x[0]-bBoxTres,y[0]-bBoxTres)], outline=255)
imn = pygame.image.frombuffer(im.tostring(), (640,480), "RGB")
screen.blit(imn, (0,0))
pygame.display.flip()

Yes, the first piece of code picks up on 1 face inside a picture.
Does it give you a traceback, or just not pick up any face?
Make sure you have all the required modules and the dll from this site.

Head posistion needs to be frontal, and not too angled.
This was written in Python2.6 and uses PIL 1.1.6 I beleive.

It can now recognize multiple faces, it is real-time and requires a webcam.

#fdtest.cpp mostly ported to python
#Multi face
#Tech B.
#3/9/2010
#Version 1.5

from VideoCapture import Device
from ctypes import *
import Image, ImageDraw, os, time, pygame, sys
from pygame.locals import *
from psyco import full
full()

#add style and clear screen
os.system('color 02')

fd = cdll.LoadLibrary("fdlib.dll") #dll found at http://www.kyb.mpg.de/bs/people/kienzle/facedemo/facedemo.htm


#assignments
cam = Device()
pygame.init()
screen = pygame.display.set_mode((640,480))
pygame.display.set_caption('Facial Recognition')
font = pygame.font.SysFont("Curier",26)

pixX = 0
pixY = 0
pixList = []

w = c_int(640)
h = c_int(480)
threshold = c_int(0)

x = c_int * 256
y = c_int * 256
size = c_int * 256
x = x()
y = y()
size = size()


graydata = c_ubyte * (640*480)
graydata = graydata()
fps = 25.0
while 1:
    for event in pygame.event.get():
        if event.type == pygame.QUIT: sys.exit()
    im = cam.getImage()
    draw = ImageDraw.Draw(im)
    img = im.convert("L") #convert to grayscale
    imd = list(img.getdata()) #graydata needed
    cnt = 0
    pixX = 0
    pixY = 0
    cnt = 0
    for pix in imd: #Convert python data types to ctypes
        graydata[cnt] = imd[cnt]
        cnt+=1

    fd.fdlib_detectfaces(byref(graydata), w, h, threshold)
    n = fd.fdlib_getndetections() #number of faces
    i = 0
    while i < n:
        fd.fdlib_getdetection(c_int(i), x, y, size)
        bBoxTres = size[0]/2
        draw.rectangle([(x[0]+bBoxTres,y[0]+bBoxTres),(x[0]-bBoxTres,y[0]-bBoxTres)], outline=224)
        i += 1
    faceNumber = font.render('Number of Faces: '+str(n), True, (46,224,1))
    imn = pygame.image.frombuffer(im.tostring(), (640,480), "RGB")
    screen.blit(imn, (0,0))
    screen.blit(faceNumber,(0,0))
    pygame.display.flip()
    pygame.time.delay(int(1000 * 1.0/fps))

I see the problem. I'm reading from 640x480 image.

Okay I thought it was the problem, I couldn't get it to pick it up, I did however try the aplication that came with the dll, and it couldn't pick it up either. Try a defrent picture.

And as for the image size thing, the new code has im.size from the Image module.
example:

import Image

im = Image.open('test.jpg')

imSize = im.size

xSize = imSize[0]
ySize = imSize[1]

Yeah, that's about the way I updated it. I went ahead and also updated the pixel algorithm
from:

while pixX*pixY <= (xSize*ySize):
    pixList.append(im.getpixel((pixX,pixY)))
    pixX += 1
    if pixX == xSize:
        pixX = 0
        pixY += 1
    if pixY == ySize:
        break

To this:

for pix in imd:
        graydata[cnt] = imd[cnt]
        cnt+=1

Its a lot quicker, and less expensive.

I'm sorry, I don't know VB yet. I'm taking it next semister; school doesn't start till aug 23.

It shouldn't be hard if you know how to code in VB. Just figure out how to call functions in the dll.

I'll work on it when I start class as a side project, if your willing to wait that long.