def grasp_fast_rcnn_inference_single_image_rotated(scores, boxes, tilts, zs,
image_shape, score_thresh,
nms_thresh, topk_per_image):
"""
Single-image inference. Return rotated bounding-box detection results by thresholding
on scores and applying rotated non-maximum suppression (Rotated NMS).
Args:
Same as `fast_rcnn_inference_rotated`, but with rotated boxes, scores, and image shapes
per image.
Returns:
Same as `fast_rcnn_inference_rotated`, but for only one image.
"""
valid_mask = torch.isfinite(boxes).all(dim=1) & torch.isfinite(scores).all(
dim=1) & torch.isfinite(tilts).all(dim=1) & torch.isfinite(zs).all(
dim=1)
if not valid_mask.all():
boxes = boxes[valid_mask]
scores = scores[valid_mask]
tilts = tilts[valid_mask]
zs = zs[valid_mask]
B = 5 # box dimension
scores = scores[:, :-1]
num_bbox_reg_classes = boxes.shape[1] // B
# Convert to Boxes to use the `clip` function ...
boxes = RotatedBoxes(boxes.reshape(-1, B))
boxes.clip(image_shape)
boxes = boxes.tensor.view(-1, num_bbox_reg_classes, B) # R x C x B
# Filter results based on detection scores
filter_mask = scores > score_thresh # R x K
# R' x 2. First column contains indices of the R predictions;
# Second column contains indices of classes.
filter_inds = filter_mask.nonzero()
if num_bbox_reg_classes == 1:
boxes = boxes[filter_inds[:, 0], 0]
else:
boxes = boxes[filter_mask]
scores = scores[filter_mask]
tilts = tilts[filter_inds[:, 0]]
zs = zs[filter_inds[:, 0]]
# Apply per-class Rotated NMS
keep = batched_nms_rotated(boxes, scores, filter_inds[:, 1], nms_thresh)
if topk_per_image >= 0:
keep = keep[:topk_per_image]
boxes, scores, filter_inds = boxes[keep], scores[keep], filter_inds[keep]
tilts, zs = tilts[keep], zs[keep]
result = Instances(image_shape)
result.pred_boxes = RotatedBoxes(boxes)
result.scores = scores
result.pred_classes = filter_inds[:, 1]
result.pred_zs = torch.flatten(zs)
result.pred_tilts = torch.flatten(tilts)
return result, filter_inds[:, 0]
def find_top_rrpn_proposals(
proposals,
pred_objectness_logits,
images,
nms_thresh,
pre_nms_topk,
post_nms_topk,
min_box_side_len,
training,
):
"""
For each feature map, select the `pre_nms_topk` highest scoring proposals,
apply NMS, clip proposals, and remove small boxes. Return the `post_nms_topk`
highest scoring proposals among all the feature maps if `training` is True,
otherwise, returns the highest `post_nms_topk` scoring proposals for each
feature map.
Args:
proposals (list[Tensor]): A list of L tensors. Tensor i has shape (N, Hi*Wi*A, 5).
All proposal predictions on the feature maps.
pred_objectness_logits (list[Tensor]): A list of L tensors. Tensor i has shape (N, Hi*Wi*A).
images (ImageList): Input images as an :class:`ImageList`.
nms_thresh (float): IoU threshold to use for NMS
pre_nms_topk (int): number of top k scoring proposals to keep before applying NMS.
When RRPN is run on multiple feature maps (as in FPN) this number is per
feature map.
post_nms_topk (int): number of top k scoring proposals to keep after applying NMS.
When RRPN is run on multiple feature maps (as in FPN) this number is total,
over all feature maps.
min_box_side_len (float): minimum proposal box side length in pixels (absolute units
wrt input images).
training (bool): True if proposals are to be used in training, otherwise False.
This arg exists only to support a legacy bug; look for the "NB: Legacy bug ..."
comment.
Returns:
proposals (list[Instances]): list of N Instances. The i-th Instances
stores post_nms_topk object proposals for image i.
"""
image_sizes = images.image_sizes # in (h, w) order
num_images = len(image_sizes)
device = proposals[0].device
# 1. Select top-k anchor for every level and every image
topk_scores = [] # #lvl Tensor, each of shape N x topk
topk_proposals = []
level_ids = [] # #lvl Tensor, each of shape (topk,)
batch_idx = torch.arange(num_images, device=device)
for level_id, proposals_i, logits_i in zip(itertools.count(), proposals,
pred_objectness_logits):
Hi_Wi_A = logits_i.shape[1]
num_proposals_i = min(pre_nms_topk, Hi_Wi_A)
# sort is faster than topk (https://github.com/pytorch/pytorch/issues/22812)
# topk_scores_i, topk_idx = logits_i.topk(num_proposals_i, dim=1)
logits_i, idx = logits_i.sort(descending=True, dim=1)
topk_scores_i = logits_i[batch_idx, :num_proposals_i]
topk_idx = idx[batch_idx, :num_proposals_i]
# each is N x topk
topk_proposals_i = proposals_i[batch_idx[:, None],
topk_idx] # N x topk x 5
topk_proposals.append(topk_proposals_i)
topk_scores.append(topk_scores_i)
level_ids.append(
torch.full((num_proposals_i, ),
level_id,
dtype=torch.int64,
device=device))
# 2. Concat all levels together
topk_scores = cat(topk_scores, dim=1)
topk_proposals = cat(topk_proposals, dim=1)
level_ids = cat(level_ids, dim=0)
# 3. For each image, run a per-level NMS, and choose topk results.
results = []
for n, image_size in enumerate(image_sizes):
boxes = RotatedBoxes(topk_proposals[n])
scores_per_img = topk_scores[n]
valid_mask = torch.isfinite(
boxes.tensor).all(dim=1) & torch.isfinite(scores_per_img)
if not valid_mask.all():
boxes = boxes[valid_mask]
scores_per_img = scores_per_img[valid_mask]
boxes.clip(image_size)
# filter empty boxes
keep = boxes.nonempty(threshold=min_box_side_len)
lvl = level_ids
if keep.sum().item() != len(boxes):
boxes, scores_per_img, lvl = (boxes[keep], scores_per_img[keep],
level_ids[keep])
keep = batched_nms_rotated(boxes.tensor, scores_per_img, lvl,
nms_thresh)
# In Detectron1, there was different behavior during training vs. testing.
# (https://github.com/facebookresearch/Detectron/issues/459)
# During training, topk is over the proposals from *all* images in the training batch.
# During testing, it is over the proposals for each image separately.
# As a result, the training behavior becomes batch-dependent,
# and the configuration "POST_NMS_TOPK_TRAIN" end up relying on the batch size.
# This bug is addressed in Detectron2 to make the behavior independent of batch size.
keep = keep[:post_nms_topk]
res = Instances(image_size)
res.proposal_boxes = boxes[keep]
res.objectness_logits = scores_per_img[keep]
results.append(res)
return results
