'**SUMMARY**
We roll old school with this vanilla threshold function. It takes your image
converts it to grayscale, and applies a threshold. Values above the threshold
are white, values below the threshold are black (note this is in contrast to
binarize... which is a stupid function that drives me up a wall). The resulting
black and white image is returned.
**PARAMETERS**
* *value* - the threshold, goes between 0 and 255.
**RETURNS**
A black and white SimpleCV image.
**EXAMPLE**
>>> img = Image("purplemonkeydishwasher.png")
>>> result = img.threshold(42)
**NOTES**
THRESHOLD RULES BINARIZE DROOLS!
**SEE ALSO**
:py:meth:`binarize`'

def threshold(self, value):

    gray = self._getGrayscaleBitmap()
    result = self.getEmpty(1)
    cv.Threshold(gray, result, value, 255, cv.CV_THRESH_BINARY)
    retVal = Image(result)
    return retVal
