Provides BlackHat operation on images
img_ret=cv_blackhat(image,kernel_type,kernel_size)
Input Image on which the operation of BlackHat is to be performed
It accepts Integer/Float as Input 1->MORPH_RECT 2-> MORPH_ELLIPSE 3-> MORPH_CROSS
It accepts a list as input specifying the size of Kernel needed example [5,5]
Returned Image after blackhat operation
Performs Blackhat Operation
Blackhat gives the difference between the closing of the input image and input image. For more information on kernel type see structuring element section of http://opencv-python-tutroals.readthedocs.org/en/latest/py_tutorials/py_imgproc/py_morphological_ops/py_morphological_ops.html