dcn.py 文件源码

def identify_saliency(grads):
    """Identify top k saliency scores.

       Args.
            grads: gradient of the entropy wrt features
       Trick.
            use tf.nn.top_k ops to extract position indices
    """

    M = tf.sqrt(tf.reduce_sum(tf.square(grads),3)+1e-8)
    top_k_values, top_k_idxs = tf.nn.top_k(ops.flatten(M), N_PATCHES, sorted=False)

    # shuffle patch indices for batch normalization
    top_k_idxs = tf.random_shuffle(tf.transpose(top_k_idxs))
    top_k_idxs = tf.transpose(top_k_idxs)

    return top_k_values, top_k_idxs, M