def get_geoindex(geo_matrix, index_pixel):
    """ This functions returns geo-coordinates of pixels of image coordinate.
    Args:
        param geo_matrix: this is a tuple which tells us which image coordinate corresponds
                          to which geo-coordinates.
        type geo_matrix: tuple of 2 list.
        
        param index_pixel: coordinates of our reqired point in image.
        type index_pixel: tuple.
        
    Returns: 
         returns the  geo coodinates of a coordinates of a given pixel in an image
    """
    if geo_matrix is None or index_pixel is None:
        raise TypeError("NoneType value in one of the arguments")
    if not isinstance(geo_matrix,tuple):
        raise TypeError('Please provide a tuple for geo_matrix argument.')
 
    if not isinstance(index_pixel,tuple):
        raise TypeError('Please provide a tuple for index_pixel.')

    vX_geo = geo_matrix[0][index_pixel[0]]
    vL = len(geo_matrix[1])
    # instead of using this modify the y as difference value.
    vY_geo = geo_matrix[1][index_pixel[1]]
    #vY_geo = geo_matrix[1][vL - index_pixel[1]]
    
    return (vX_geo,vY_geo)