def test_batched_nms_rotated_0_degree_cuda(self):
# torch.manual_seed(0)
N = 2000
num_classes = 50
boxes, scores = self._create_tensors(N)
idxs = torch.randint(0, num_classes, (N, ))
rotated_boxes = torch.zeros(N, 5)
rotated_boxes[:, 0] = (boxes[:, 0] + boxes[:, 2]) / 2.0
rotated_boxes[:, 1] = (boxes[:, 1] + boxes[:, 3]) / 2.0
rotated_boxes[:, 2] = boxes[:, 2] - boxes[:, 0]
rotated_boxes[:, 3] = boxes[:, 3] - boxes[:, 1]
err_msg = "Rotated NMS with 0 degree is incompatible with horizontal NMS for IoU={}"
for iou in [0.2, 0.5, 0.8]:
backup = boxes.clone()
keep_ref = batched_nms(boxes.cuda(), scores.cuda(), idxs, iou)
assert torch.allclose(boxes,
backup), "boxes modified by batched_nms"
backup = rotated_boxes.clone()
keep = batched_nms_rotated(rotated_boxes.cuda(), scores.cuda(),
idxs, iou)
assert torch.allclose(
rotated_boxes,
backup), "rotated_boxes modified by batched_nms_rotated"
self.assertLessEqual(nms_edit_distance(keep, keep_ref), 1,
err_msg.format(iou))
def merge_branch_instances(instances, num_branch, nms_thrsh, topk_per_image):
"""
Merge detection results from different branches of TridentNet.
Return detection results by applying non-maximum suppression (NMS) on bounding boxes
and keep the unsuppressed boxes and other instances (e.g mask) if any.
Args:
instances (list[Instances]): A list of N * num_branch instances that store detection
results. Contain N images and each image has num_branch instances.
num_branch (int): Number of branches used for merging detection results for each image.
nms_thresh (float): The threshold to use for box non-maximum suppression. Value in [0, 1].
topk_per_image (int): The number of top scoring detections to return. Set < 0 to return
all detections.
Returns:
results: (list[Instances]): A list of N instances, one for each image in the batch,
that stores the topk most confidence detections after merging results from multiple
branches.
"""
if num_branch == 1:
return instances
batch_size = len(instances) // num_branch
results = []
for i in range(batch_size):
instance = Instances.cat(
[instances[i + batch_size * j] for j in range(num_branch)])
# Apply per-class NMS
keep = batched_nms(instance.pred_boxes.tensor, instance.scores,
instance.pred_classes, nms_thrsh)
keep = keep[:topk_per_image]
result = instance[keep]
results.append(result)
return results
def find_top_rpn_proposals(
proposals,
pred_objectness_logits,
images,
nms_thresh,
pre_nms_topk,
post_nms_topk,
min_box_side_len,
training, # pylint: disable=W0613
):
"""
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, 4).
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 RPN 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 RPN 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 4
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 = Boxes(topk_proposals[n])
scores_per_img = topk_scores[n]
# 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(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 cvpods 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
def inference_single_image(self, box_cls, box_delta, anchors, image_size):
"""
Single-image inference. Return bounding-box detection results by thresholding
on scores and applying non-maximum suppression (NMS).
Arguments:
box_cls (list[Tensor]): list of #feature levels. Each entry contains
tensor of size (H x W x A, K)
box_delta (list[Tensor]): Same shape as 'box_cls' except that K becomes 4.
anchors (list[Boxes]): list of #feature levels. Each entry contains
a Boxes object, which contains all the anchors for that
image in that feature level.
image_size (tuple(H, W)): a tuple of the image height and width.
Returns:
Same as `inference`, but for only one image.
"""
boxes_all = []
scores_all = []
class_idxs_all = []
# Iterate over every feature level
for box_cls_i, box_reg_i, anchors_i in zip(box_cls, box_delta,
anchors):
# (HxWxAxK,)
box_cls_i = box_cls_i.flatten().sigmoid_()
# Keep top k top scoring indices only.
num_topk = min(self.topk_candidates, box_reg_i.size(0))
# torch.sort is actually faster than .topk (at least on GPUs)
predicted_prob, topk_idxs = box_cls_i.sort(descending=True)
predicted_prob = predicted_prob[:num_topk]
topk_idxs = topk_idxs[:num_topk]
# filter out the proposals with low confidence score
keep_idxs = predicted_prob > self.score_threshold
predicted_prob = predicted_prob[keep_idxs]
topk_idxs = topk_idxs[keep_idxs]
anchor_idxs = topk_idxs // self.num_classes
classes_idxs = topk_idxs % self.num_classes
box_reg_i = box_reg_i[anchor_idxs]
anchors_i = anchors_i[anchor_idxs]
# predict boxes
predicted_boxes = self.box2box_transform.apply_deltas(
box_reg_i, anchors_i.tensor)
boxes_all.append(predicted_boxes)
scores_all.append(predicted_prob)
class_idxs_all.append(classes_idxs)
boxes_all, scores_all, class_idxs_all = [
cat(x) for x in [boxes_all, scores_all, class_idxs_all]
]
keep = batched_nms(boxes_all, scores_all, class_idxs_all,
self.nms_threshold)
keep = keep[:self.max_detections_per_image]
result = Instances(image_size)
result.pred_boxes = Boxes(boxes_all[keep])
result.scores = scores_all[keep]
result.pred_classes = class_idxs_all[keep]
return result