|
|
@@ -1,166 +0,0 @@
|
|
|
-import numpy as np
|
|
|
-import torch
|
|
|
-
|
|
|
-
|
|
|
-class Yolov4Matcher(object):
|
|
|
- def __init__(self, num_classes, num_anchors, anchor_size, iou_thresh):
|
|
|
- self.num_classes = num_classes
|
|
|
- self.num_anchors = num_anchors
|
|
|
- self.iou_thresh = iou_thresh
|
|
|
- self.anchor_boxes = np.array(
|
|
|
- [[0., 0., anchor[0], anchor[1]]
|
|
|
- for anchor in anchor_size]
|
|
|
- ) # [KA, 4]
|
|
|
-
|
|
|
- def compute_iou(self, anchor_boxes, gt_box):
|
|
|
- """
|
|
|
- anchor_boxes : ndarray -> [KA, 4] (cx, cy, bw, bh).
|
|
|
- gt_box : ndarray -> [1, 4] (cx, cy, bw, bh).
|
|
|
- """
|
|
|
- # anchors: [KA, 4]
|
|
|
- anchors_xyxy = np.zeros_like(anchor_boxes)
|
|
|
- anchors_area = anchor_boxes[..., 2] * anchor_boxes[..., 3]
|
|
|
- # convert [cx, cy, bw, bh] -> [x1, y1, x2, y2]
|
|
|
- anchors_xyxy[..., :2] = anchor_boxes[..., :2] - anchor_boxes[..., 2:] * 0.5 # x1y1
|
|
|
- anchors_xyxy[..., 2:] = anchor_boxes[..., :2] + anchor_boxes[..., 2:] * 0.5 # x2y2
|
|
|
-
|
|
|
- # expand gt_box: [1, 4] -> [KA, 4]
|
|
|
- gt_box = np.array(gt_box).reshape(-1, 4)
|
|
|
- gt_box = np.repeat(gt_box, anchors_xyxy.shape[0], axis=0)
|
|
|
- gt_box_area = gt_box[..., 2] * gt_box[..., 3]
|
|
|
- # convert [cx, cy, bw, bh] -> [x1, y1, x2, y2]
|
|
|
- gt_box_xyxy = np.zeros_like(gt_box)
|
|
|
- gt_box_xyxy[..., :2] = gt_box[..., :2] - gt_box[..., 2:] * 0.5 # x1y1
|
|
|
- gt_box_xyxy[..., 2:] = gt_box[..., :2] + gt_box[..., 2:] * 0.5 # x2y2
|
|
|
-
|
|
|
- # intersection
|
|
|
- inter_w = np.minimum(anchors_xyxy[:, 2], gt_box_xyxy[:, 2]) - \
|
|
|
- np.maximum(anchors_xyxy[:, 0], gt_box_xyxy[:, 0])
|
|
|
- inter_h = np.minimum(anchors_xyxy[:, 3], gt_box_xyxy[:, 3]) - \
|
|
|
- np.maximum(anchors_xyxy[:, 1], gt_box_xyxy[:, 1])
|
|
|
- inter_area = inter_w * inter_h
|
|
|
-
|
|
|
- # union
|
|
|
- union_area = anchors_area + gt_box_area - inter_area
|
|
|
-
|
|
|
- # iou
|
|
|
- iou = inter_area / union_area
|
|
|
- iou = np.clip(iou, a_min=1e-10, a_max=1.0)
|
|
|
-
|
|
|
- return iou
|
|
|
-
|
|
|
- @torch.no_grad()
|
|
|
- def __call__(self, fmp_sizes, fpn_strides, targets):
|
|
|
- """
|
|
|
- fmp_size: (List) [fmp_h, fmp_w]
|
|
|
- fpn_strides: (List) -> [8, 16, 32, ...] stride of network output.
|
|
|
- targets: (Dict) dict{'boxes': [...],
|
|
|
- 'labels': [...],
|
|
|
- 'orig_size': ...}
|
|
|
- """
|
|
|
- assert len(fmp_sizes) == len(fpn_strides)
|
|
|
- # prepare
|
|
|
- bs = len(targets)
|
|
|
- gt_objectness = [
|
|
|
- torch.zeros([bs, fmp_h, fmp_w, self.num_anchors, 1])
|
|
|
- for (fmp_h, fmp_w) in fmp_sizes
|
|
|
- ]
|
|
|
- gt_classes = [
|
|
|
- torch.zeros([bs, fmp_h, fmp_w, self.num_anchors, self.num_classes])
|
|
|
- for (fmp_h, fmp_w) in fmp_sizes
|
|
|
- ]
|
|
|
- gt_bboxes = [
|
|
|
- torch.zeros([bs, fmp_h, fmp_w, self.num_anchors, 4])
|
|
|
- for (fmp_h, fmp_w) in fmp_sizes
|
|
|
- ]
|
|
|
-
|
|
|
- for batch_index in range(bs):
|
|
|
- targets_per_image = targets[batch_index]
|
|
|
- # [N,]
|
|
|
- tgt_cls = targets_per_image["labels"].numpy()
|
|
|
- # [N, 4]
|
|
|
- tgt_box = targets_per_image['boxes'].numpy()
|
|
|
-
|
|
|
- for gt_box, gt_label in zip(tgt_box, tgt_cls):
|
|
|
- # get a bbox coords
|
|
|
- x1, y1, x2, y2 = gt_box.tolist()
|
|
|
- # xyxy -> cxcywh
|
|
|
- xc, yc = (x2 + x1) * 0.5, (y2 + y1) * 0.5
|
|
|
- bw, bh = x2 - x1, y2 - y1
|
|
|
- gt_box = [0, 0, bw, bh]
|
|
|
-
|
|
|
- # check target
|
|
|
- if bw < 1. or bh < 1.:
|
|
|
- # invalid target
|
|
|
- continue
|
|
|
-
|
|
|
- # compute IoU
|
|
|
- iou = self.compute_iou(self.anchor_boxes, gt_box)
|
|
|
- iou_mask = (iou > self.iou_thresh)
|
|
|
-
|
|
|
- label_assignment_results = []
|
|
|
- if iou_mask.sum() == 0:
|
|
|
- # We assign the anchor box with highest IoU score.
|
|
|
- iou_ind = np.argmax(iou)
|
|
|
-
|
|
|
- level = iou_ind // self.num_anchors # pyramid level
|
|
|
- anchor_idx = iou_ind - level * self.num_anchors # anchor index
|
|
|
-
|
|
|
- # get the corresponding stride
|
|
|
- stride = fpn_strides[level]
|
|
|
-
|
|
|
- # compute the grid cell
|
|
|
- xc_s = xc / stride
|
|
|
- yc_s = yc / stride
|
|
|
- grid_x = int(xc_s)
|
|
|
- grid_y = int(yc_s)
|
|
|
-
|
|
|
- label_assignment_results.append([grid_x, grid_y, level, anchor_idx])
|
|
|
- else:
|
|
|
- for iou_ind, iou_m in enumerate(iou_mask):
|
|
|
- if iou_m:
|
|
|
- level = iou_ind // self.num_anchors # pyramid level
|
|
|
- anchor_idx = iou_ind - level * self.num_anchors # anchor index
|
|
|
-
|
|
|
- # get the corresponding stride
|
|
|
- stride = fpn_strides[level]
|
|
|
-
|
|
|
- # compute the gride cell
|
|
|
- xc_s = xc / stride
|
|
|
- yc_s = yc / stride
|
|
|
- grid_x = int(xc_s)
|
|
|
- grid_y = int(yc_s)
|
|
|
-
|
|
|
- label_assignment_results.append([grid_x, grid_y, level, anchor_idx])
|
|
|
-
|
|
|
- # label assignment
|
|
|
- for result in label_assignment_results:
|
|
|
- grid_x, grid_y, level, anchor_idx = result
|
|
|
- stride = fpn_strides[level]
|
|
|
- x1s, y1s = x1 / stride, y1 / stride
|
|
|
- x2s, y2s = x2 / stride, y2 / stride
|
|
|
- fmp_h, fmp_w = fmp_sizes[level]
|
|
|
-
|
|
|
- # 3x3 center sampling
|
|
|
- for j in range(grid_y - 1, grid_y + 2):
|
|
|
- for i in range(grid_x - 1, grid_x + 2):
|
|
|
- is_in_box = (j >= y1s and j < y2s) and (i >= x1s and i < x2s)
|
|
|
- is_valid = (j >= 0 and j < fmp_h) and (i >= 0 and i < fmp_w)
|
|
|
-
|
|
|
- if is_in_box and is_valid:
|
|
|
- # obj
|
|
|
- gt_objectness[level][batch_index, j, i, anchor_idx] = 1.0
|
|
|
- # cls
|
|
|
- cls_ont_hot = torch.zeros(self.num_classes)
|
|
|
- cls_ont_hot[int(gt_label)] = 1.0
|
|
|
- gt_classes[level][batch_index, j, i, anchor_idx] = cls_ont_hot
|
|
|
- # box
|
|
|
- gt_bboxes[level][batch_index, j, i, anchor_idx] = torch.as_tensor([x1, y1, x2, y2])
|
|
|
-
|
|
|
- # [B, M, C]
|
|
|
- gt_objectness = torch.cat([gt.view(bs, -1, 1) for gt in gt_objectness], dim=1).float()
|
|
|
- gt_classes = torch.cat([gt.view(bs, -1, self.num_classes) for gt in gt_classes], dim=1).float()
|
|
|
- gt_bboxes = torch.cat([gt.view(bs, -1, 4) for gt in gt_bboxes], dim=1).float()
|
|
|
-
|
|
|
- return gt_objectness, gt_classes, gt_bboxes
|
|
|
-
|