Method encode

examples/mlperf/helpers.py:317–336

(self, reference_boxes, proposals)

    self.apply_to_remove = apply_to_remove

  def encode(self, reference_boxes, proposals):
    TO_REMOVE = self.apply_to_remove  # TODO remove
    ex_widths = proposals[..., 2] - proposals[..., 0] + TO_REMOVE
    ex_heights = proposals[..., 3] - proposals[..., 1] + TO_REMOVE
    ex_ctr_x = proposals[..., 0] + 0.5 * ex_widths
    ex_ctr_y = proposals[..., 1] + 0.5 * ex_heights

    gt_widths = reference_boxes[..., 2] - reference_boxes[..., 0] + TO_REMOVE
    gt_heights = reference_boxes[..., 3] - reference_boxes[..., 1] + TO_REMOVE
    gt_ctr_x = reference_boxes[..., 0] + 0.5 * gt_widths
    gt_ctr_y = reference_boxes[..., 1] + 0.5 * gt_heights

    wx, wy, ww, wh = self.weights
    targets_dx = wx * (gt_ctr_x - ex_ctr_x) / ex_widths
    targets_dy = wy * (gt_ctr_y - ex_ctr_y) / ex_heights
    targets_dw = ww * Tensor.log(gt_widths / ex_widths)
    targets_dh = wh * Tensor.log(gt_heights / ex_heights)

    targets = Tensor.stack(targets_dx, targets_dy, targets_dw, targets_dh, dim=-1)
    return targets

  def decode(self, rel_codes, boxes):
    boxes = boxes.cast(rel_codes.dtype)