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Thursday, August 30, 2012

Python script using OpenCV to detect / recognition faces on photos

This is old tutorial make long time ago by me to detect faces on photos.

If you know more about OpenCV module , then is easy to understand source code.

First I load the modules:

import opencv.cv as cv
import opencv.highgui as gui
import opencv

Next I set the variables and data blocks processed some particular features of the modules loaded.

hc = cv.cvLoad("haarcascade_frontalface_default.xml")
img = gui.cvLoadImage("me.jpg",cv.CV_BGR2RGB)
storage = cv.cvCreateMemStorage(0)
cascade = cv.cvLoadHaarClassifierCascade('haarcascade_frontalface_alt.xml',cv.cvSize(1, 1))
grayscale = cv.cvCreateImage(cv.cvSize(img.width, img.height), 8, 1)
cv.cvCvtColor(img, grayscale, cv.CV_BGR2GRAY)

This is part where is detect faces and save the output like a jpeg image.

faces = cv.cvHaarDetectObjects(grayscale, cascade,\ 
storage,1.2,2,cv.CV_HAAR_DO_CANNY_PRUNING, cv.cvSize(5, 5))

if faces:
 for i in faces:
  cv.cvRectangle(img, cv.cvPoint( int(i.x), int(i.y)),cv.cvPoint(int(i.x + i.width), int(i.y + i.height)),cv.CV_RGB(0, 255, 0), 3, 8, 0)
gui.cvSaveImage("faces_detected.jpg", img)

The haarcascade_frontalface_default.xml file it's from internet, but you can create one if you want.

Maybe in the next tutorial I will show how.

Let's see the result. The input image file is:

... and the result is:

Saturday, August 25, 2012

The new tutorial about pstats python module.

Today I make a new tutorial about pstats python module.

The pstats module is a statistics browser for reading and examining profiler program.

This is provided in the modules cProfile, profile and pstats.

Because it's a long tutorial with long row , I put this tutorial on my tutorials website.

You can find it here on Python section.

Friday, August 24, 2012

Python 3.2 : Start with Django 1.4.

Although most of us prefer the python version 2.6, today I tried to install the latest version of django and python 2.3.2 .
Make a new folder , named test-dj .
$mkdir test-dj
$cd test-dj/
On the official site, I got the two archives:
django-django-1.4-919-ge57338f.zip
Python-3.2.3.tar.bz2
I will start with the installation of python. We unzip the archive:
$tar xvjf Python-3.2.3.tar.bz2 
We execute the following commands to install python:
$cd Python-3.2.3
$./configure
$make all
$sudo make altinstall
# python3.2 setup.py install 
Let's see what we have.
$ whereis  python3
python3: /usr/lib/python3.0 /usr/local/bin/python3.2m-config
/usr/local/bin/python3.2 /usr/local/bin/python3.2m 
/usr/local/lib/python3.2
As you see it's ...
python3.2
python3.2m
python3.2m-config
In accordance with the PEP-3149 we can got this:
Python implementations MAY include additional flags in the file name tag as appropriate. For example, on POSIX systems these flags will also contribute to the file name:

        * --with-pydebug (flag: d)
        * --with-pymalloc (flag: m)
        * --with-wide-unicode (flag: u)

Now we need to install django.
$unzip django-django-1.4-919-ge57338f.zip
Go to the django folder:
$cd django-django-e57338f/
# python3.2 setup.py install 
Now , we can test it:
# python3.2
Python 3.2.3 (default, Aug 24 2012, 19:24:21) 
[GCC 4.4.1] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import django 
>>> print(django.get_version())
1.5
>>> 
I will make another tutorial about how to configure the django to have one website.