Example of lti::integralImage

Integral images are a method for efficiently computing the sum of all pixels
within a rectangular region with less than a dozen of sums, regardless of the
size of the image.

This is a simple example to illustrate the use of the lti::integralImage
functor, which is called that way just because that is the name used in the
technical literature for the method.  In the library a more adequate name would
have been integralChannel, but nobody could have guessed what was meant with
it.

The example implements a "box-filter", in which each pixel receives the value
of the average of a neighborhood.


Compilation
-----------

1. Ensure that the library has been already created:

   cd {YOUR-BASE-DIR}/ltilib-2/linux/
   make libsr libsd

2. Compile the example:

   cd {YOUR-BASE-DIR}/ltilib-2/examples/integralImage/
   make

If you don't find a Makefile in the directory, copy the one in
ltilib-2/examples/template/Makefile into this directory.

Running
-------

From the directory of the example, call the executable giving it as
argument the name of an image.

   cd {YOUR-BASE-DIR}/ltilib-2/examples/integralImage/
   ./integralImage ../../img/baboon.png


