This op produces Region of Interests from given bounding boxes(bbox_deltas) encoded wrt anchors according to eq.2 in arXiv:1506.01497
tf.raw_ops.GenerateBoundingBoxProposals(
    scores,
    bbox_deltas,
    image_info,
    anchors,
    nms_threshold,
    pre_nms_topn,
    min_size,
    post_nms_topn=300,
    name=None
)
  The op selects top `pre_nms_topn` scoring boxes, decodes them with respect to anchors,
  applies non-maximal suppression on overlapping boxes with higher than
  `nms_threshold` intersection-over-union (iou) value, discarding boxes where shorter
  side is less than `min_size`.
  Inputs:
  `scores`: A 4D tensor of shape [Batch, Height, Width, Num Anchors] containing the scores per anchor at given position
  `bbox_deltas`: is a tensor of shape [Batch, Height, Width, 4 x Num Anchors] boxes encoded to each anchor
  `anchors`: A 1D tensor of shape [4 x Num Anchors], representing the anchors.
  Outputs:
  `rois`: output RoIs, a 3D tensor of shape [Batch, post_nms_topn, 4], padded by 0 if less than post_nms_topn candidates found.
  `roi_probabilities`: probability scores of each roi in 'rois', a 2D tensor of shape [Batch,post_nms_topn], padded with 0 if needed, sorted by scores.
| Returns | |
|---|---|
| A tuple of Tensorobjects (rois, roi_probabilities). | |
| rois | A Tensorof typefloat32. | 
| roi_probabilities | A Tensorof typefloat32. |