'**SUMMARY**
Calculate the integral image and return it as a numpy array.
The integral image gives the sum of all of the pixels above and to the
right of a given pixel location. It is useful for computing Haar cascades.
The return type is a numpy array the same size of the image. The integral
image requires 32Bit values which are not easily supported by the SimpleCV
Image class.
**PARAMETERS**
* *tilted*  - if tilted is true we tilt the image 45 degrees and then calculate the results.
**RETURNS**
A numpy array of the values.
**EXAMPLE**
>>> img = Image("logo")
>>> derp = img.integralImage()
**SEE ALSO**
http://en.wikipedia.org/wiki/Summed_area_table'

def integralImage(self, tilted=False):

    if tilted:
        img2 = cv.CreateImage(((self.width + 1), (self.height + 1)), cv.IPL_DEPTH_32F, 1)
        img3 = cv.CreateImage(((self.width + 1), (self.height + 1)), cv.IPL_DEPTH_32F, 1)
        cv.Integral(self._getGrayscaleBitmap(), img3, None, img2)
    else:
        img2 = cv.CreateImage(((self.width + 1), (self.height + 1)), cv.IPL_DEPTH_32F, 1)
        cv.Integral(self._getGrayscaleBitmap(), img2)
    return np.array(cv.GetMat(img2))
