proposal.py 文件源码

def _combine_box_and_delta(self, bboxes, deltas):
    widths = bboxes[:, 2] - bboxes[:, 0] + 1.0
    heights = bboxes[:, 3] - bboxes[:, 1] + 1.0
    ctr_x = bboxes[:, 0] + 0.5 * widths
    ctr_y = bboxes[:, 1] + 0.5 * heights

    # use 0::4 to make it a [-1, 1] matrix, while the columns are 4
    dx = deltas[:, 0::4]
    dy = deltas[:, 1::4]
    dw = deltas[:, 2::4]
    dh = deltas[:, 3::4]

    # do not understand the transformation
    # TF ?????reshape????????????????
    pred_ctr_x = tf.reshape(dx * widths[:, tf.newaxis] + ctr_x[:, tf.newaxis], (-1,))
    pred_ctr_y = tf.reshape(dy * heights[:, tf.newaxis] + ctr_y[:, tf.newaxis], (-1,))
    pred_w = tf.reshape(tf.exp(dw) * widths[:, tf.newaxis], (-1,))
    pred_h = tf.reshape(tf.exp(dh) * heights[:, tf.newaxis], (-1,))

    pred_boxes = tf.pack(
      [pred_ctr_x - 0.5 * pred_w,
       pred_ctr_y - 0.5 * pred_h,
       pred_ctr_x + 0.5 * pred_w,
       pred_ctr_y + 0.5 * pred_h],
      axis=1
    )

    return pred_boxes