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OpenPCDet/pcdet/models/dense_heads/anchor_head_multi.py

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2025-09-21 20:19:05 +08:00
import numpy as np
import torch
import torch.nn as nn
from ..backbones_2d import BaseBEVBackbone
from .anchor_head_template import AnchorHeadTemplate
class SingleHead(BaseBEVBackbone):
def __init__(self, model_cfg, input_channels, num_class, num_anchors_per_location, code_size, rpn_head_cfg=None,
head_label_indices=None, separate_reg_config=None):
super().__init__(rpn_head_cfg, input_channels)
self.num_anchors_per_location = num_anchors_per_location
self.num_class = num_class
self.code_size = code_size
self.model_cfg = model_cfg
self.separate_reg_config = separate_reg_config
self.register_buffer('head_label_indices', head_label_indices)
if self.separate_reg_config is not None:
code_size_cnt = 0
self.conv_box = nn.ModuleDict()
self.conv_box_names = []
num_middle_conv = self.separate_reg_config.NUM_MIDDLE_CONV
num_middle_filter = self.separate_reg_config.NUM_MIDDLE_FILTER
conv_cls_list = []
c_in = input_channels
for k in range(num_middle_conv):
conv_cls_list.extend([
nn.Conv2d(
c_in, num_middle_filter,
kernel_size=3, stride=1, padding=1, bias=False
),
nn.BatchNorm2d(num_middle_filter),
nn.ReLU()
])
c_in = num_middle_filter
conv_cls_list.append(nn.Conv2d(
c_in, self.num_anchors_per_location * self.num_class,
kernel_size=3, stride=1, padding=1
))
self.conv_cls = nn.Sequential(*conv_cls_list)
for reg_config in self.separate_reg_config.REG_LIST:
reg_name, reg_channel = reg_config.split(':')
reg_channel = int(reg_channel)
cur_conv_list = []
c_in = input_channels
for k in range(num_middle_conv):
cur_conv_list.extend([
nn.Conv2d(
c_in, num_middle_filter,
kernel_size=3, stride=1, padding=1, bias=False
),
nn.BatchNorm2d(num_middle_filter),
nn.ReLU()
])
c_in = num_middle_filter
cur_conv_list.append(nn.Conv2d(
c_in, self.num_anchors_per_location * int(reg_channel),
kernel_size=3, stride=1, padding=1, bias=True
))
code_size_cnt += reg_channel
self.conv_box[f'conv_{reg_name}'] = nn.Sequential(*cur_conv_list)
self.conv_box_names.append(f'conv_{reg_name}')
for m in self.conv_box.modules():
if isinstance(m, nn.Conv2d):
nn.init.kaiming_normal_(m.weight, mode='fan_out', nonlinearity='relu')
if m.bias is not None:
nn.init.constant_(m.bias, 0)
assert code_size_cnt == code_size, f'Code size does not match: {code_size_cnt}:{code_size}'
else:
self.conv_cls = nn.Conv2d(
input_channels, self.num_anchors_per_location * self.num_class,
kernel_size=1
)
self.conv_box = nn.Conv2d(
input_channels, self.num_anchors_per_location * self.code_size,
kernel_size=1
)
if self.model_cfg.get('USE_DIRECTION_CLASSIFIER', None) is not None:
self.conv_dir_cls = nn.Conv2d(
input_channels,
self.num_anchors_per_location * self.model_cfg.NUM_DIR_BINS,
kernel_size=1
)
else:
self.conv_dir_cls = None
self.use_multihead = self.model_cfg.get('USE_MULTIHEAD', False)
self.init_weights()
def init_weights(self):
pi = 0.01
if isinstance(self.conv_cls, nn.Conv2d):
nn.init.constant_(self.conv_cls.bias, -np.log((1 - pi) / pi))
else:
nn.init.constant_(self.conv_cls[-1].bias, -np.log((1 - pi) / pi))
def forward(self, spatial_features_2d):
ret_dict = {}
spatial_features_2d = super().forward({'spatial_features': spatial_features_2d})['spatial_features_2d']
cls_preds = self.conv_cls(spatial_features_2d)
if self.separate_reg_config is None:
box_preds = self.conv_box(spatial_features_2d)
else:
box_preds_list = []
for reg_name in self.conv_box_names:
box_preds_list.append(self.conv_box[reg_name](spatial_features_2d))
box_preds = torch.cat(box_preds_list, dim=1)
if not self.use_multihead:
box_preds = box_preds.permute(0, 2, 3, 1).contiguous()
cls_preds = cls_preds.permute(0, 2, 3, 1).contiguous()
else:
H, W = box_preds.shape[2:]
batch_size = box_preds.shape[0]
box_preds = box_preds.view(-1, self.num_anchors_per_location,
self.code_size, H, W).permute(0, 1, 3, 4, 2).contiguous()
cls_preds = cls_preds.view(-1, self.num_anchors_per_location,
self.num_class, H, W).permute(0, 1, 3, 4, 2).contiguous()
box_preds = box_preds.view(batch_size, -1, self.code_size)
cls_preds = cls_preds.view(batch_size, -1, self.num_class)
if self.conv_dir_cls is not None:
dir_cls_preds = self.conv_dir_cls(spatial_features_2d)
if self.use_multihead:
dir_cls_preds = dir_cls_preds.view(
-1, self.num_anchors_per_location, self.model_cfg.NUM_DIR_BINS, H, W).permute(0, 1, 3, 4,
2).contiguous()
dir_cls_preds = dir_cls_preds.view(batch_size, -1, self.model_cfg.NUM_DIR_BINS)
else:
dir_cls_preds = dir_cls_preds.permute(0, 2, 3, 1).contiguous()
else:
dir_cls_preds = None
ret_dict['cls_preds'] = cls_preds
ret_dict['box_preds'] = box_preds
ret_dict['dir_cls_preds'] = dir_cls_preds
return ret_dict
class AnchorHeadMulti(AnchorHeadTemplate):
def __init__(self, model_cfg, input_channels, num_class, class_names, grid_size, point_cloud_range,
predict_boxes_when_training=True, **kwargs):
super().__init__(
model_cfg=model_cfg, num_class=num_class, class_names=class_names, grid_size=grid_size,
point_cloud_range=point_cloud_range, predict_boxes_when_training=predict_boxes_when_training
)
self.model_cfg = model_cfg
self.separate_multihead = self.model_cfg.get('SEPARATE_MULTIHEAD', False)
if self.model_cfg.get('SHARED_CONV_NUM_FILTER', None) is not None:
shared_conv_num_filter = self.model_cfg.SHARED_CONV_NUM_FILTER
self.shared_conv = nn.Sequential(
nn.Conv2d(input_channels, shared_conv_num_filter, 3, stride=1, padding=1, bias=False),
nn.BatchNorm2d(shared_conv_num_filter, eps=1e-3, momentum=0.01),
nn.ReLU(),
)
else:
self.shared_conv = None
shared_conv_num_filter = input_channels
self.rpn_heads = None
self.make_multihead(shared_conv_num_filter)
def make_multihead(self, input_channels):
rpn_head_cfgs = self.model_cfg.RPN_HEAD_CFGS
rpn_heads = []
class_names = []
for rpn_head_cfg in rpn_head_cfgs:
class_names.extend(rpn_head_cfg['HEAD_CLS_NAME'])
for rpn_head_cfg in rpn_head_cfgs:
num_anchors_per_location = sum([self.num_anchors_per_location[class_names.index(head_cls)]
for head_cls in rpn_head_cfg['HEAD_CLS_NAME']])
head_label_indices = torch.from_numpy(np.array([
self.class_names.index(cur_name) + 1 for cur_name in rpn_head_cfg['HEAD_CLS_NAME']
]))
rpn_head = SingleHead(
self.model_cfg, input_channels,
len(rpn_head_cfg['HEAD_CLS_NAME']) if self.separate_multihead else self.num_class,
num_anchors_per_location, self.box_coder.code_size, rpn_head_cfg,
head_label_indices=head_label_indices,
separate_reg_config=self.model_cfg.get('SEPARATE_REG_CONFIG', None)
)
rpn_heads.append(rpn_head)
self.rpn_heads = nn.ModuleList(rpn_heads)
def forward(self, data_dict):
spatial_features_2d = data_dict['spatial_features_2d']
if self.shared_conv is not None:
spatial_features_2d = self.shared_conv(spatial_features_2d)
ret_dicts = []
for rpn_head in self.rpn_heads:
ret_dicts.append(rpn_head(spatial_features_2d))
cls_preds = [ret_dict['cls_preds'] for ret_dict in ret_dicts]
box_preds = [ret_dict['box_preds'] for ret_dict in ret_dicts]
ret = {
'cls_preds': cls_preds if self.separate_multihead else torch.cat(cls_preds, dim=1),
'box_preds': box_preds if self.separate_multihead else torch.cat(box_preds, dim=1),
}
if self.model_cfg.get('USE_DIRECTION_CLASSIFIER', False):
dir_cls_preds = [ret_dict['dir_cls_preds'] for ret_dict in ret_dicts]
ret['dir_cls_preds'] = dir_cls_preds if self.separate_multihead else torch.cat(dir_cls_preds, dim=1)
self.forward_ret_dict.update(ret)
if self.training:
targets_dict = self.assign_targets(
gt_boxes=data_dict['gt_boxes']
)
self.forward_ret_dict.update(targets_dict)
if not self.training or self.predict_boxes_when_training:
batch_cls_preds, batch_box_preds = self.generate_predicted_boxes(
batch_size=data_dict['batch_size'],
cls_preds=ret['cls_preds'], box_preds=ret['box_preds'], dir_cls_preds=ret.get('dir_cls_preds', None)
)
if isinstance(batch_cls_preds, list):
multihead_label_mapping = []
for idx in range(len(batch_cls_preds)):
multihead_label_mapping.append(self.rpn_heads[idx].head_label_indices)
data_dict['multihead_label_mapping'] = multihead_label_mapping
data_dict['batch_cls_preds'] = batch_cls_preds
data_dict['batch_box_preds'] = batch_box_preds
data_dict['cls_preds_normalized'] = False
return data_dict
def get_cls_layer_loss(self):
loss_weights = self.model_cfg.LOSS_CONFIG.LOSS_WEIGHTS
if 'pos_cls_weight' in loss_weights:
pos_cls_weight = loss_weights['pos_cls_weight']
neg_cls_weight = loss_weights['neg_cls_weight']
else:
pos_cls_weight = neg_cls_weight = 1.0
cls_preds = self.forward_ret_dict['cls_preds']
box_cls_labels = self.forward_ret_dict['box_cls_labels']
if not isinstance(cls_preds, list):
cls_preds = [cls_preds]
batch_size = int(cls_preds[0].shape[0])
cared = box_cls_labels >= 0 # [N, num_anchors]
positives = box_cls_labels > 0
negatives = box_cls_labels == 0
negative_cls_weights = negatives * 1.0 * neg_cls_weight
cls_weights = (negative_cls_weights + pos_cls_weight * positives).float()
reg_weights = positives.float()
if self.num_class == 1:
# class agnostic
box_cls_labels[positives] = 1
pos_normalizer = positives.sum(1, keepdim=True).float()
reg_weights /= torch.clamp(pos_normalizer, min=1.0)
cls_weights /= torch.clamp(pos_normalizer, min=1.0)
cls_targets = box_cls_labels * cared.type_as(box_cls_labels)
one_hot_targets = torch.zeros(
*list(cls_targets.shape), self.num_class + 1, dtype=cls_preds[0].dtype, device=cls_targets.device
)
one_hot_targets.scatter_(-1, cls_targets.unsqueeze(dim=-1).long(), 1.0)
one_hot_targets = one_hot_targets[..., 1:]
start_idx = c_idx = 0
cls_losses = 0
for idx, cls_pred in enumerate(cls_preds):
cur_num_class = self.rpn_heads[idx].num_class
cls_pred = cls_pred.view(batch_size, -1, cur_num_class)
if self.separate_multihead:
one_hot_target = one_hot_targets[:, start_idx:start_idx + cls_pred.shape[1],
c_idx:c_idx + cur_num_class]
c_idx += cur_num_class
else:
one_hot_target = one_hot_targets[:, start_idx:start_idx + cls_pred.shape[1]]
cls_weight = cls_weights[:, start_idx:start_idx + cls_pred.shape[1]]
cls_loss_src = self.cls_loss_func(cls_pred, one_hot_target, weights=cls_weight) # [N, M]
cls_loss = cls_loss_src.sum() / batch_size
cls_loss = cls_loss * loss_weights['cls_weight']
cls_losses += cls_loss
start_idx += cls_pred.shape[1]
assert start_idx == one_hot_targets.shape[1]
tb_dict = {
'rpn_loss_cls': cls_losses.item()
}
return cls_losses, tb_dict
def get_box_reg_layer_loss(self):
box_preds = self.forward_ret_dict['box_preds']
box_dir_cls_preds = self.forward_ret_dict.get('dir_cls_preds', None)
box_reg_targets = self.forward_ret_dict['box_reg_targets']
box_cls_labels = self.forward_ret_dict['box_cls_labels']
positives = box_cls_labels > 0
reg_weights = positives.float()
pos_normalizer = positives.sum(1, keepdim=True).float()
reg_weights /= torch.clamp(pos_normalizer, min=1.0)
if not isinstance(box_preds, list):
box_preds = [box_preds]
batch_size = int(box_preds[0].shape[0])
if isinstance(self.anchors, list):
if self.use_multihead:
anchors = torch.cat(
[anchor.permute(3, 4, 0, 1, 2, 5).contiguous().view(-1, anchor.shape[-1])
for anchor in self.anchors], dim=0
)
else:
anchors = torch.cat(self.anchors, dim=-3)
else:
anchors = self.anchors
anchors = anchors.view(1, -1, anchors.shape[-1]).repeat(batch_size, 1, 1)
start_idx = 0
box_losses = 0
tb_dict = {}
for idx, box_pred in enumerate(box_preds):
box_pred = box_pred.view(
batch_size, -1,
box_pred.shape[-1] // self.num_anchors_per_location if not self.use_multihead else box_pred.shape[-1]
)
box_reg_target = box_reg_targets[:, start_idx:start_idx + box_pred.shape[1]]
reg_weight = reg_weights[:, start_idx:start_idx + box_pred.shape[1]]
# sin(a - b) = sinacosb-cosasinb
if box_dir_cls_preds is not None:
box_pred_sin, reg_target_sin = self.add_sin_difference(box_pred, box_reg_target)
loc_loss_src = self.reg_loss_func(box_pred_sin, reg_target_sin, weights=reg_weight) # [N, M]
else:
loc_loss_src = self.reg_loss_func(box_pred, box_reg_target, weights=reg_weight) # [N, M]
loc_loss = loc_loss_src.sum() / batch_size
loc_loss = loc_loss * self.model_cfg.LOSS_CONFIG.LOSS_WEIGHTS['loc_weight']
box_losses += loc_loss
tb_dict['rpn_loss_loc'] = tb_dict.get('rpn_loss_loc', 0) + loc_loss.item()
if box_dir_cls_preds is not None:
if not isinstance(box_dir_cls_preds, list):
box_dir_cls_preds = [box_dir_cls_preds]
dir_targets = self.get_direction_target(
anchors, box_reg_targets,
dir_offset=self.model_cfg.DIR_OFFSET,
num_bins=self.model_cfg.NUM_DIR_BINS
)
box_dir_cls_pred = box_dir_cls_preds[idx]
dir_logit = box_dir_cls_pred.view(batch_size, -1, self.model_cfg.NUM_DIR_BINS)
weights = positives.type_as(dir_logit)
weights /= torch.clamp(weights.sum(-1, keepdim=True), min=1.0)
weight = weights[:, start_idx:start_idx + box_pred.shape[1]]
dir_target = dir_targets[:, start_idx:start_idx + box_pred.shape[1]]
dir_loss = self.dir_loss_func(dir_logit, dir_target, weights=weight)
dir_loss = dir_loss.sum() / batch_size
dir_loss = dir_loss * self.model_cfg.LOSS_CONFIG.LOSS_WEIGHTS['dir_weight']
box_losses += dir_loss
tb_dict['rpn_loss_dir'] = tb_dict.get('rpn_loss_dir', 0) + dir_loss.item()
start_idx += box_pred.shape[1]
return box_losses, tb_dict