detect.py 文件源码

def MatchedFilter(M, t):
    """
    Performs the matched filter algorithm for target
    detection.

    Parameters:
        M: `numpy array`
            2d matrix of HSI data (N x p).

        t: `numpy array`
            A target endmember (p).

    Returns: `numpy array`
        Vector of detector output (N).

    References:
      X Jin, S Paswater, H Cline.  "A Comparative Study of Target Detection
     Algorithms for Hyperspectral Imagery."  SPIE Algorithms and Technologies
     for Multispectral, Hyperspectral, and Ultraspectral Imagery XV.  Vol
     7334.  2009.
    """

    N, p = M.shape
    # Remove mean from data
    u = M.mean(axis=0)
    M = M - np.kron(np.ones((N, 1)), u)
    t = t - u;

    R_hat = np.cov(M.T)
    G = lin.inv(R_hat)

    tmp = np.array(np.dot(t.T, np.dot(G, t)))
    w = np.dot(G, t)
    return np.dot(w, M.T) / tmp