otx.algorithms.detection.adapters.mmdet.models.assigners#

Initial file for mmdetection assigners.

Classes

CustomMaxIoUAssigner(pos_iou_thr, neg_iou_thr)

Assign a corresponding gt bbox or background to each bbox.
class otx.algorithms.detection.adapters.mmdet.models.assigners.CustomMaxIoUAssigner(pos_iou_thr, neg_iou_thr, min_pos_iou=0.0, gt_max_assign_all=True, ignore_iof_thr=-1, ignore_wrt_candidates=True, match_low_quality=True, gpu_assign_thr=-1, iou_calculator={'type': 'BboxOverlaps2D'})[source]#

Bases: MaxIoUAssigner

Assign a corresponding gt bbox or background to each bbox.

Each proposals will be assigned with -1, or a semi-positive integer indicating the ground truth index.

  • -1: negative sample, no assigned gt

  • semi-positive integer: positive sample, index (0-based) of assigned gt

This CustomMaxIoUAssigner patches assign funtion of mmdet’s MaxIouAssigner so that it can prevent CPU OOM for images whose gt is extremely large

assign(bboxes, gt_bboxes, gt_bboxes_ignore=None, gt_labels=None)[source]#

Assign gt to bboxes.

This method assign a gt bbox to every bbox (proposal/anchor), each bbox will be assigned with -1, or a semi-positive number. -1 means negative sample, semi-positive number is the index (0-based) of assigned gt. The assignment is done in following steps, the order matters.

Especially CustomMaxIoUAssigner split gt_bboxes tensor into small tensors when gt_bboxes is too large.

  1. assign every bbox to the background

  2. assign proposals whose iou with all gts < neg_iou_thr to 0

  3. for each bbox, if the iou with its nearest gt >= pos_iou_thr, assign it to that bbox

  4. for each gt bbox, assign its nearest proposals (may be more than one) to itself

Parameters:

  • bboxes (Tensor) – Bounding boxes to be assigned, shape(n, 4).

  • gt_bboxes (Tensor) – Groundtruth boxes, shape (k, 4).

  • gt_bboxes_ignore (Tensor, optional) – Ground truth bboxes that are labelled as ignored, e.g., crowd boxes in COCO.

  • gt_labels (Tensor, optional) – Label of gt_bboxes, shape (k, ).

Returns:

The assign result.

Return type:

AssignResult

Example

>>> self = MaxIoUAssigner(0.5, 0.5)
>>> bboxes = torch.Tensor([[0, 0, 10, 10], [10, 10, 20, 20]])
>>> gt_bboxes = torch.Tensor([[0, 0, 10, 9]])
>>> assign_result = self.assign(bboxes, gt_bboxes)
>>> expected_gt_inds = torch.LongTensor([1, 0])
>>> assert torch.all(assign_result.gt_inds == expected_gt_inds)