import tensorflow as tf


        num_topk = config.class_num_joints[(params['model_scope'] if 'all' not in params['model_scope'] else '*')] // 2
        gather_col = tf.nn.top_k(temp_loss, k=num_topk, sorted=True)[1]
        gather_row = tf.reshape(tf.tile(tf.reshape(tf.range(cur_batch_size), [-1, 1]), [1, num_topk]), [-1, 1])
