mmdet/models/dense_heads/dino_head.py

# Copyright (c) OpenMMLab. All rights reserved.
import copy
from typing import Dict, List, Tuple
from torch import Tensor

import torch
import torch.nn as nn
import torch.nn.functional as F
from mmcv.cnn import Linear
from mmcv.ops.nms import nms
from mmengine.model import bias_init_with_prob, constant_init
from mmengine.structures import InstanceData

from mmdet.registry import MODELS
from mmdet.structures import SampleList
from mmdet.structures.bbox import bbox_cxcywh_to_xyxy, bbox_xyxy_to_cxcywh
from mmdet.utils import InstanceList, OptInstanceList, reduce_mean
from ..utils import multi_apply
from ..layers import inverse_sigmoid
from .detr_head import DETRHead


# def adjust_bbox_to_pixel(bboxes: Tensor):
#     # 向下取整得到目标的左上角坐标
#     adjusted_bboxes = torch.floor(bboxes)
#     # 向上取整得到目标的右下角坐标
#     adjusted_bboxes[:, 2:] = torch.ceil(bboxes[:, 2:])
#     return adjusted_bboxes


def adjust_bbox_to_pixel(bboxes: Tensor):
    # 四舍五入取整坐标
    adjusted_bboxes = torch.round(bboxes)
    return adjusted_bboxes




@MODELS.register_module()
class DINOHead(DETRHead):
    r"""Head of the DINO: DETR with Improved DeNoising Anchor Boxes
    for End-to-End Object Detection

    Code is modified from the `official github repo
    <https://github.com/IDEA-Research/DINO>`_.

    More details can be found in the `paper
    <https://arxiv.org/abs/2203.03605>`_ .
    """
    def __init__(self,
                 *args,
                 share_pred_layer: bool = False,
                 num_pred_layer: int = 6,
                 as_two_stage: bool = False,
                 pre_bboxes_round: bool = False,
                 **kwargs) -> None:
        self.share_pred_layer = share_pred_layer
        self.num_pred_layer = num_pred_layer
        self.as_two_stage = as_two_stage
        self.pre_bboxes_round = pre_bboxes_round
        super().__init__(*args, **kwargs)

    def _init_layers(self) -> None:
        """Initialize classification branch and regression branch of head."""
        fc_cls = Linear(self.embed_dims, self.cls_out_channels)

        reg_branch = []
        for _ in range(self.num_reg_fcs):
            reg_branch.append(Linear(self.embed_dims, self.embed_dims))
            reg_branch.append(nn.ReLU())
        reg_branch.append(Linear(self.embed_dims, 4))
        reg_branch = nn.Sequential(*reg_branch)

        if self.share_pred_layer:
            self.cls_branches = nn.ModuleList(
                [fc_cls for _ in range(self.num_pred_layer)])
            self.reg_branches = nn.ModuleList(
                [reg_branch for _ in range(self.num_pred_layer)])
        else:
            self.cls_branches = nn.ModuleList(
                [copy.deepcopy(fc_cls) for _ in range(self.num_pred_layer)])
            self.reg_branches = nn.ModuleList([
                copy.deepcopy(reg_branch) for _ in range(self.num_pred_layer)
            ])


    def init_weights(self) -> None:
        """Initialize weights of the Deformable DETR head."""
        if self.loss_cls.use_sigmoid:
            bias_init = bias_init_with_prob(0.01)
            for m in self.cls_branches:
                nn.init.constant_(m.bias, bias_init)
        for m in self.reg_branches:
            constant_init(m[-1], 0, bias=0)
        nn.init.constant_(self.reg_branches[0][-1].bias.data[2:], -2.0)
        if self.as_two_stage:
            for m in self.reg_branches:
                nn.init.constant_(m[-1].bias.data[2:], 0.0)

    def forward(self, hidden_states: Tensor,
                references: List[Tensor]) -> Tuple[Tensor]:
        """Forward function.

        Args:
            hidden_states (Tensor): Hidden states output from each decoder
                layer, has shape (num_decoder_layers, bs, num_queries, dim).
            references (list[Tensor]): List of the reference from the decoder.
                The first reference is the `init_reference` (initial) and the
                other num_decoder_layers(6) references are `inter_references`
                (intermediate). The `init_reference` has shape (bs,
                num_queries, 4) when `as_two_stage` of the detector is `True`,
                otherwise (bs, num_queries, 2). Each `inter_reference` has
                shape (bs, num_queries, 4) when `with_box_refine` of the
                detector is `True`, otherwise (bs, num_queries, 2). The
                coordinates are arranged as (cx, cy) when the last dimension is
                2, and (cx, cy, w, h) when it is 4.

        Returns:
            tuple[Tensor]: results of head containing the following tensor.

            - all_layers_outputs_classes (Tensor): Outputs from the
              classification head, has shape (num_decoder_layers, bs,
              num_queries, cls_out_channels).
            - all_layers_outputs_coords (Tensor): Sigmoid outputs from the
              regression head with normalized coordinate format (cx, cy, w,
              h), has shape (num_decoder_layers, bs, num_queries, 4) with the
              last dimension arranged as (cx, cy, w, h).
        """
        all_layers_outputs_classes = []
        all_layers_outputs_coords = []

        for layer_id in range(hidden_states.shape[0]):
            reference = inverse_sigmoid(references[layer_id])
            # NOTE The last reference will not be used.
            hidden_state = hidden_states[layer_id]
            outputs_class = self.cls_branches[layer_id](hidden_state)
            tmp_reg_preds = self.reg_branches[layer_id](hidden_state)
            if reference.shape[-1] == 4:
                # When `layer` is 0 and `as_two_stage` of the detector
                # is `True`, or when `layer` is greater than 0 and
                # `with_box_refine` of the detector is `True`.
                tmp_reg_preds += reference
            else:
                # When `layer` is 0 and `as_two_stage` of the detector
                # is `False`, or when `layer` is greater than 0 and
                # `with_box_refine` of the detector is `False`.
                assert reference.shape[-1] == 2
                tmp_reg_preds[..., :2] += reference
            outputs_coord = tmp_reg_preds.sigmoid()
            all_layers_outputs_classes.append(outputs_class)
            all_layers_outputs_coords.append(outputs_coord)



        all_layers_outputs_classes = torch.stack(all_layers_outputs_classes)
        all_layers_outputs_coords = torch.stack(all_layers_outputs_coords)

        return all_layers_outputs_classes, all_layers_outputs_coords

    def loss(self, hidden_states: Tensor, references: List[Tensor],
             enc_outputs_class: Tensor, enc_outputs_coord: Tensor,
             batch_data_samples: SampleList, dn_meta: Dict[str, int]) -> dict:
        """Perform forward propagation and loss calculation of the detection
        head on the queries of the upstream network.

        Args:
            hidden_states (Tensor): Hidden states output from each decoder
                layer, has shape (num_decoder_layers, bs, num_queries_total,
                dim), where `num_queries_total` is the sum of
                `num_denoising_queries` and `num_matching_queries` when
                `self.training` is `True`, else `num_matching_queries`.
            references (list[Tensor]): List of the reference from the decoder.
                The first reference is the `init_reference` (initial) and the
                other num_decoder_layers(6) references are `inter_references`
                (intermediate). The `init_reference` has shape (bs,
                num_queries_total, 4) and each `inter_reference` has shape
                (bs, num_queries, 4) with the last dimension arranged as
                (cx, cy, w, h).
            enc_outputs_class (Tensor): The score of each point on encode
                feature map, has shape (bs, num_feat_points, cls_out_channels).
            enc_outputs_coord (Tensor): The proposal generate from the
                encode feature map, has shape (bs, num_feat_points, 4) with the
                last dimension arranged as (cx, cy, w, h).
            batch_data_samples (list[:obj:`DetDataSample`]): The Data
                Samples. It usually includes information such as
                `gt_instance`, `gt_panoptic_seg` and `gt_sem_seg`.
            dn_meta (Dict[str, int]): The dictionary saves information about
              group collation, including 'num_denoising_queries' and
              'num_denoising_groups'. It will be used for split outputs of
              denoising and matching parts and loss calculation.

        Returns:
            dict: A dictionary of loss components.
        """
        batch_gt_instances = []
        batch_img_metas = []
        for data_sample in batch_data_samples:
            batch_img_metas.append(data_sample.metainfo)
            batch_gt_instances.append(data_sample.gt_instances)

        outs = self(hidden_states, references)
        loss_inputs = outs + (enc_outputs_class, enc_outputs_coord,
                              batch_gt_instances, batch_img_metas, dn_meta)
        losses = self.loss_by_feat(*loss_inputs)
        return losses

    def loss_by_feat(
        self,
        all_layers_cls_scores: Tensor,
        all_layers_bbox_preds: Tensor,
        enc_cls_scores: Tensor,
        enc_bbox_preds: Tensor,
        batch_gt_instances: InstanceList,
        batch_img_metas: List[dict],
        dn_meta: Dict[str, int],
        batch_gt_instances_ignore: OptInstanceList = None
    ) -> Dict[str, Tensor]:
        """Loss function.

        Args:
            all_layers_cls_scores (Tensor): Classification scores of all
                decoder layers, has shape (num_decoder_layers, bs,
                num_queries_total, cls_out_channels), where
                `num_queries_total` is the sum of `num_denoising_queries`
                and `num_matching_queries`.
            all_layers_bbox_preds (Tensor): Regression outputs of all decoder
                layers. Each is a 4D-tensor with normalized coordinate format
                (cx, cy, w, h) and has shape (num_decoder_layers, bs,
                num_queries_total, 4).
            enc_cls_scores (Tensor): The score of each point on encode
                feature map, has shape (bs, num_feat_points, cls_out_channels).
            enc_bbox_preds (Tensor): The proposal generate from the encode
                feature map, has shape (bs, num_feat_points, 4) with the last
                dimension arranged as (cx, cy, w, h).
            batch_gt_instances (list[:obj:`InstanceData`]): Batch of
                gt_instance. It usually includes ``bboxes`` and ``labels``
                attributes.
            batch_img_metas (list[dict]): Meta information of each image, e.g.,
                image size, scaling factor, etc.
            dn_meta (Dict[str, int]): The dictionary saves information about
                group collation, including 'num_denoising_queries' and
                'num_denoising_groups'. It will be used for split outputs of
                denoising and matching parts and loss calculation.
            batch_gt_instances_ignore (list[:obj:`InstanceData`], optional):
                Batch of gt_instances_ignore. It includes ``bboxes`` attribute
                data that is ignored during training and testing.
                Defaults to None.

        Returns:
            dict[str, Tensor]: A dictionary of loss components.
        """
        # extract denoising and matching part of outputs
        (all_layers_matching_cls_scores, all_layers_matching_bbox_preds,
         all_layers_denoising_cls_scores, all_layers_denoising_bbox_preds) = \
            self.split_outputs(
                all_layers_cls_scores, all_layers_bbox_preds, dn_meta)

        loss_dict = super().loss_by_feat(
            all_layers_matching_cls_scores, all_layers_matching_bbox_preds,
            batch_gt_instances, batch_img_metas, batch_gt_instances_ignore)
        # NOTE DETRHead.loss_by_feat but not DeformableDETRHead.loss_by_feat
        # is called, because the encoder loss calculations are different
        # between DINO and DeformableDETR.

        # loss of proposal generated from encode feature map.
        if enc_cls_scores is not None:
            # NOTE The enc_loss calculation of the DINO is
            # different from that of Deformable DETR.
            enc_loss_cls, enc_losses_bbox, enc_losses_iou = \
                self.loss_by_feat_single(
                    enc_cls_scores, enc_bbox_preds,
                    batch_gt_instances=batch_gt_instances,
                    batch_img_metas=batch_img_metas)
            loss_dict['enc_loss_cls'] = enc_loss_cls
            loss_dict['enc_loss_bbox'] = enc_losses_bbox
            loss_dict['enc_loss_iou'] = enc_losses_iou

        if all_layers_denoising_cls_scores is not None:
            # calculate denoising loss from all decoder layers
            dn_losses_cls, dn_losses_bbox, dn_losses_iou = self.loss_dn(
                all_layers_denoising_cls_scores,
                all_layers_denoising_bbox_preds,
                batch_gt_instances=batch_gt_instances,
                batch_img_metas=batch_img_metas,
                dn_meta=dn_meta)
            # collate denoising loss
            loss_dict['dn_loss_cls'] = dn_losses_cls[-1]
            loss_dict['dn_loss_bbox'] = dn_losses_bbox[-1]
            loss_dict['dn_loss_iou'] = dn_losses_iou[-1]
            for num_dec_layer, (loss_cls_i, loss_bbox_i, loss_iou_i) in \
                    enumerate(zip(dn_losses_cls[:-1], dn_losses_bbox[:-1],
                                  dn_losses_iou[:-1])):
                loss_dict[f'd{num_dec_layer}.dn_loss_cls'] = loss_cls_i
                loss_dict[f'd{num_dec_layer}.dn_loss_bbox'] = loss_bbox_i
                loss_dict[f'd{num_dec_layer}.dn_loss_iou'] = loss_iou_i
        return loss_dict

    def loss_dn(self, all_layers_denoising_cls_scores: Tensor,
                all_layers_denoising_bbox_preds: Tensor,
                batch_gt_instances: InstanceList, batch_img_metas: List[dict],
                dn_meta: Dict[str, int]) -> Tuple[List[Tensor]]:
        """Calculate denoising loss.

        Args:
            all_layers_denoising_cls_scores (Tensor): Classification scores of
                all decoder layers in denoising part, has shape (
                num_decoder_layers, bs, num_denoising_queries,
                cls_out_channels).
            all_layers_denoising_bbox_preds (Tensor): Regression outputs of all
                decoder layers in denoising part. Each is a 4D-tensor with
                normalized coordinate format (cx, cy, w, h) and has shape
                (num_decoder_layers, bs, num_denoising_queries, 4).
            batch_gt_instances (list[:obj:`InstanceData`]): Batch of
                gt_instance. It usually includes ``bboxes`` and ``labels``
                attributes.
            batch_img_metas (list[dict]): Meta information of each image, e.g.,
                image size, scaling factor, etc.
            dn_meta (Dict[str, int]): The dictionary saves information about
              group collation, including 'num_denoising_queries' and
              'num_denoising_groups'. It will be used for split outputs of
              denoising and matching parts and loss calculation.

        Returns:
            Tuple[List[Tensor]]: The loss_dn_cls, loss_dn_bbox, and loss_dn_iou
            of each decoder layers.
        """
        return multi_apply(
            self._loss_dn_single,
            all_layers_denoising_cls_scores,
            all_layers_denoising_bbox_preds,
            batch_gt_instances=batch_gt_instances,
            batch_img_metas=batch_img_metas,
            dn_meta=dn_meta)

    def _loss_dn_single(self, dn_cls_scores: Tensor, dn_bbox_preds: Tensor,
                        batch_gt_instances: InstanceList,
                        batch_img_metas: List[dict],
                        dn_meta: Dict[str, int]) -> Tuple[Tensor]:
        """Denoising loss for outputs from a single decoder layer.

        Args:
            dn_cls_scores (Tensor): Classification scores of a single decoder
                layer in denoising part, has shape (bs, num_denoising_queries,
                cls_out_channels).
            dn_bbox_preds (Tensor): Regression outputs of a single decoder
                layer in denoising part. Each is a 4D-tensor with normalized
                coordinate format (cx, cy, w, h) and has shape
                (bs, num_denoising_queries, 4).
            batch_gt_instances (list[:obj:`InstanceData`]): Batch of
                gt_instance. It usually includes ``bboxes`` and ``labels``
                attributes.
            batch_img_metas (list[dict]): Meta information of each image, e.g.,
                image size, scaling factor, etc.
            dn_meta (Dict[str, int]): The dictionary saves information about
              group collation, including 'num_denoising_queries' and
              'num_denoising_groups'. It will be used for split outputs of
              denoising and matching parts and loss calculation.

        Returns:
            Tuple[Tensor]: A tuple including `loss_cls`, `loss_box` and
            `loss_iou`.
        """
        cls_reg_targets = self.get_dn_targets(batch_gt_instances,
                                              batch_img_metas, dn_meta)
        (labels_list, label_weights_list, bbox_targets_list, bbox_weights_list,
         num_total_pos, num_total_neg) = cls_reg_targets
        labels = torch.cat(labels_list, 0)
        label_weights = torch.cat(label_weights_list, 0)
        bbox_targets = torch.cat(bbox_targets_list, 0)
        bbox_weights = torch.cat(bbox_weights_list, 0)

        # classification loss
        cls_scores = dn_cls_scores.reshape(-1, self.cls_out_channels)
        # construct weighted avg_factor to match with the official DETR repo
        cls_avg_factor = \
            num_total_pos * 1.0 + num_total_neg * self.bg_cls_weight
        if self.sync_cls_avg_factor:
            cls_avg_factor = reduce_mean(
                cls_scores.new_tensor([cls_avg_factor]))
        cls_avg_factor = max(cls_avg_factor, 1)

        if len(cls_scores) > 0:
            loss_cls = self.loss_cls(
                cls_scores, labels, label_weights, avg_factor=cls_avg_factor)
        else:
            loss_cls = torch.zeros(
                1, dtype=cls_scores.dtype, device=cls_scores.device)

        # Compute the average number of gt boxes across all gpus, for
        # normalization purposes
        num_total_pos = loss_cls.new_tensor([num_total_pos])
        num_total_pos = torch.clamp(reduce_mean(num_total_pos), min=1).item()

        # construct factors used for rescale bboxes
        factors = []
        for img_meta, bbox_pred in zip(batch_img_metas, dn_bbox_preds):
            img_h, img_w = img_meta['img_shape']
            factor = bbox_pred.new_tensor([img_w, img_h, img_w,
                                           img_h]).unsqueeze(0).repeat(
                                               bbox_pred.size(0), 1)
            factors.append(factor)
        factors = torch.cat(factors)

        # DETR regress the relative position of boxes (cxcywh) in the image,
        # thus the learning target is normalized by the image size. So here
        # we need to re-scale them for calculating IoU loss
        bbox_preds = dn_bbox_preds.reshape(-1, 4)
        bboxes = bbox_cxcywh_to_xyxy(bbox_preds) * factors
        bboxes_gt = bbox_cxcywh_to_xyxy(bbox_targets) * factors

        # regression IoU loss, defaultly GIoU loss
        loss_iou = self.loss_iou(
            bboxes, bboxes_gt, bbox_weights, avg_factor=num_total_pos)

        # regression L1 loss
        loss_bbox = self.loss_bbox(
            bbox_preds, bbox_targets, bbox_weights, avg_factor=num_total_pos)
        return loss_cls, loss_bbox, loss_iou

    def get_dn_targets(self, batch_gt_instances: InstanceList,
                       batch_img_metas: dict, dn_meta: Dict[str,
                                                            int]) -> tuple:
        """Get targets in denoising part for a batch of images.

        Args:
            batch_gt_instances (list[:obj:`InstanceData`]): Batch of
                gt_instance. It usually includes ``bboxes`` and ``labels``
                attributes.
            batch_img_metas (list[dict]): Meta information of each image, e.g.,
                image size, scaling factor, etc.
            dn_meta (Dict[str, int]): The dictionary saves information about
              group collation, including 'num_denoising_queries' and
              'num_denoising_groups'. It will be used for split outputs of
              denoising and matching parts and loss calculation.

        Returns:
            tuple: a tuple containing the following targets.

            - labels_list (list[Tensor]): Labels for all images.
            - label_weights_list (list[Tensor]): Label weights for all images.
            - bbox_targets_list (list[Tensor]): BBox targets for all images.
            - bbox_weights_list (list[Tensor]): BBox weights for all images.
            - num_total_pos (int): Number of positive samples in all images.
            - num_total_neg (int): Number of negative samples in all images.
        """
        (labels_list, label_weights_list, bbox_targets_list, bbox_weights_list,
         pos_inds_list, neg_inds_list) = multi_apply(
             self._get_dn_targets_single,
             batch_gt_instances,
             batch_img_metas,
             dn_meta=dn_meta)
        num_total_pos = sum((inds.numel() for inds in pos_inds_list))
        num_total_neg = sum((inds.numel() for inds in neg_inds_list))
        return (labels_list, label_weights_list, bbox_targets_list,
                bbox_weights_list, num_total_pos, num_total_neg)

    def _get_dn_targets_single(self, gt_instances: InstanceData,
                               img_meta: dict, dn_meta: Dict[str,
                                                             int]) -> tuple:
        """Get targets in denoising part for one image.

        Args:
            gt_instances (:obj:`InstanceData`): Ground truth of instance
                annotations. It should includes ``bboxes`` and ``labels``
                attributes.
            img_meta (dict): Meta information for one image.
            dn_meta (Dict[str, int]): The dictionary saves information about
              group collation, including 'num_denoising_queries' and
              'num_denoising_groups'. It will be used for split outputs of
              denoising and matching parts and loss calculation.

        Returns:
            tuple[Tensor]: a tuple containing the following for one image.

            - labels (Tensor): Labels of each image.
            - label_weights (Tensor]): Label weights of each image.
            - bbox_targets (Tensor): BBox targets of each image.
            - bbox_weights (Tensor): BBox weights of each image.
            - pos_inds (Tensor): Sampled positive indices for each image.
            - neg_inds (Tensor): Sampled negative indices for each image.
        """
        gt_bboxes = gt_instances.bboxes
        gt_labels = gt_instances.labels
        num_groups = dn_meta['num_denoising_groups']
        num_denoising_queries = dn_meta['num_denoising_queries']
        num_queries_each_group = int(num_denoising_queries / num_groups)
        device = gt_bboxes.device

        if len(gt_labels) > 0:
            t = torch.arange(len(gt_labels), dtype=torch.long, device=device)
            t = t.unsqueeze(0).repeat(num_groups, 1)
            pos_assigned_gt_inds = t.flatten()
            pos_inds = torch.arange(
                num_groups, dtype=torch.long, device=device)
            pos_inds = pos_inds.unsqueeze(1) * num_queries_each_group + t
            pos_inds = pos_inds.flatten()
        else:
            pos_inds = pos_assigned_gt_inds = \
                gt_bboxes.new_tensor([], dtype=torch.long)

        neg_inds = pos_inds + num_queries_each_group // 2

        # label targets
        labels = gt_bboxes.new_full((num_denoising_queries, ),
                                    self.num_classes,
                                    dtype=torch.long)
        labels[pos_inds] = gt_labels[pos_assigned_gt_inds]
        label_weights = gt_bboxes.new_ones(num_denoising_queries)

        # bbox targets
        bbox_targets = torch.zeros(num_denoising_queries, 4, device=device)
        bbox_weights = torch.zeros(num_denoising_queries, 4, device=device)
        bbox_weights[pos_inds] = 1.0
        img_h, img_w = img_meta['img_shape']

        # DETR regress the relative position of boxes (cxcywh) in the image.
        # Thus the learning target should be normalized by the image size, also
        # the box format should be converted from defaultly x1y1x2y2 to cxcywh.
        factor = gt_bboxes.new_tensor([img_w, img_h, img_w,
                                       img_h]).unsqueeze(0)
        gt_bboxes_normalized = gt_bboxes / factor
        gt_bboxes_targets = bbox_xyxy_to_cxcywh(gt_bboxes_normalized)
        bbox_targets[pos_inds] = gt_bboxes_targets.repeat([num_groups, 1])

        return (labels, label_weights, bbox_targets, bbox_weights, pos_inds,
                neg_inds)

    @staticmethod
    def split_outputs(all_layers_cls_scores: Tensor,
                      all_layers_bbox_preds: Tensor,
                      dn_meta: Dict[str, int]) -> Tuple[Tensor]:
        """Split outputs of the denoising part and the matching part.

        For the total outputs of `num_queries_total` length, the former
        `num_denoising_queries` outputs are from denoising queries, and
        the rest `num_matching_queries` ones are from matching queries,
        where `num_queries_total` is the sum of `num_denoising_queries` and
        `num_matching_queries`.

        Args:
            all_layers_cls_scores (Tensor): Classification scores of all
                decoder layers, has shape (num_decoder_layers, bs,
                num_queries_total, cls_out_channels).
            all_layers_bbox_preds (Tensor): Regression outputs of all decoder
                layers. Each is a 4D-tensor with normalized coordinate format
                (cx, cy, w, h) and has shape (num_decoder_layers, bs,
                num_queries_total, 4).
            dn_meta (Dict[str, int]): The dictionary saves information about
              group collation, including 'num_denoising_queries' and
              'num_denoising_groups'.

        Returns:
            Tuple[Tensor]: a tuple containing the following outputs.

            - all_layers_matching_cls_scores (Tensor): Classification scores
              of all decoder layers in matching part, has shape
              (num_decoder_layers, bs, num_matching_queries, cls_out_channels).
            - all_layers_matching_bbox_preds (Tensor): Regression outputs of
              all decoder layers in matching part. Each is a 4D-tensor with
              normalized coordinate format (cx, cy, w, h) and has shape
              (num_decoder_layers, bs, num_matching_queries, 4).
            - all_layers_denoising_cls_scores (Tensor): Classification scores
              of all decoder layers in denoising part, has shape
              (num_decoder_layers, bs, num_denoising_queries,
              cls_out_channels).
            - all_layers_denoising_bbox_preds (Tensor): Regression outputs of
              all decoder layers in denoising part. Each is a 4D-tensor with
              normalized coordinate format (cx, cy, w, h) and has shape
              (num_decoder_layers, bs, num_denoising_queries, 4).
        """
        num_denoising_queries = dn_meta['num_denoising_queries']
        if dn_meta is not None:
            all_layers_denoising_cls_scores = \
                all_layers_cls_scores[:, :, : num_denoising_queries, :]
            all_layers_denoising_bbox_preds = \
                all_layers_bbox_preds[:, :, : num_denoising_queries, :]
            all_layers_matching_cls_scores = \
                all_layers_cls_scores[:, :, num_denoising_queries:, :]
            all_layers_matching_bbox_preds = \
                all_layers_bbox_preds[:, :, num_denoising_queries:, :]
        else:
            all_layers_denoising_cls_scores = None
            all_layers_denoising_bbox_preds = None
            all_layers_matching_cls_scores = all_layers_cls_scores
            all_layers_matching_bbox_preds = all_layers_bbox_preds
        return (all_layers_matching_cls_scores, all_layers_matching_bbox_preds,
                all_layers_denoising_cls_scores,
                all_layers_denoising_bbox_preds)

    def predict(self,
                hidden_states: Tensor,
                references: List[Tensor],
                batch_data_samples: SampleList,
                rescale: bool = True) -> InstanceList:
        """Perform forward propagation and loss calculation of the detection
        head on the queries of the upstream network.

        Args:
            hidden_states (Tensor): Hidden states output from each decoder
                layer, has shape (num_decoder_layers, num_queries, bs, dim).
            references (list[Tensor]): List of the reference from the decoder.
                The first reference is the `init_reference` (initial) and the
                other num_decoder_layers(6) references are `inter_references`
                (intermediate). The `init_reference` has shape (bs,
                num_queries, 4) when `as_two_stage` of the detector is `True`,
                otherwise (bs, num_queries, 2). Each `inter_reference` has
                shape (bs, num_queries, 4) when `with_box_refine` of the
                detector is `True`, otherwise (bs, num_queries, 2). The
                coordinates are arranged as (cx, cy) when the last dimension is
                2, and (cx, cy, w, h) when it is 4.
            batch_data_samples (list[:obj:`DetDataSample`]): The Data
                Samples. It usually includes information such as
                `gt_instance`, `gt_panoptic_seg` and `gt_sem_seg`.
            rescale (bool, optional): If `True`, return boxes in original
                image space. Defaults to `True`.

        Returns:
            list[obj:`InstanceData`]: Detection results of each image
            after the post process.
        """
        batch_img_metas = [
            data_samples.metainfo for data_samples in batch_data_samples
        ]

        outs = self(hidden_states, references)

        predictions = self.predict_by_feat(
            *outs, batch_img_metas=batch_img_metas, rescale=rescale)
        return predictions

    def predict_by_feat(self,
                        all_layers_cls_scores: Tensor,
                        all_layers_bbox_preds: Tensor,
                        batch_img_metas: List[Dict],
                        rescale: bool = False) -> InstanceList:
        """Transform a batch of output features extracted from the head into
        bbox results.

        Args:
            all_layers_cls_scores (Tensor): Classification scores of all
                decoder layers, has shape (num_decoder_layers, bs, num_queries,
                cls_out_channels).
            all_layers_bbox_preds (Tensor): Regression outputs of all decoder
                layers. Each is a 4D-tensor with normalized coordinate format
                (cx, cy, w, h) and shape (num_decoder_layers, bs, num_queries,
                4) with the last dimension arranged as (cx, cy, w, h).
            batch_img_metas (list[dict]): Meta information of each image.
            rescale (bool, optional): If `True`, return boxes in original
                image space. Default `False`.

        Returns:
            list[obj:`InstanceData`]: Detection results of each image
            after the post process.
        """
        cls_scores = all_layers_cls_scores[-1]
        bbox_preds = all_layers_bbox_preds[-1]

        result_list = []
        for img_id in range(len(batch_img_metas)):
            cls_score = cls_scores[img_id]
            bbox_pred = bbox_preds[img_id]
            img_meta = batch_img_metas[img_id]
            results = self._predict_by_feat_single(cls_score, bbox_pred,
                                                   img_meta, rescale)
            result_list.append(results)
        return result_list

    def _predict_by_feat_single(self,
                                cls_score: Tensor,
                                bbox_pred: Tensor,
                                img_meta: dict,
                                rescale: bool = True) -> InstanceData:
        """Transform outputs from the last decoder layer into bbox predictions
        for each image.

        Args:
            cls_score (Tensor): Box score logits from the last decoder layer
                for each image. Shape [num_queries, cls_out_channels].
            bbox_pred (Tensor): Sigmoid outputs from the last decoder layer
                for each image, with coordinate format (cx, cy, w, h) and
                shape [num_queries, 4].
            img_meta (dict): Image meta info.
            rescale (bool): If True, return boxes in original image
                space. Default True.

        Returns:
            :obj:`InstanceData`: Detection results of each image
            after the post process.
            Each item usually contains following keys.

                - scores (Tensor): Classification scores, has a shape
                  (num_instance, )
                - labels (Tensor): Labels of bboxes, has a shape
                  (num_instances, ).
                - bboxes (Tensor): Has a shape (num_instances, 4),
                  the last dimension 4 arrange as (x1, y1, x2, y2).
        """
        assert len(cls_score) == len(bbox_pred)  # num_queries
        max_per_img = self.test_cfg.get('max_per_img', len(cls_score))
        img_shape = img_meta['img_shape']
        # exclude background
        if self.loss_cls.use_sigmoid:
            cls_score = cls_score.sigmoid()
            scores, indexes = cls_score.view(-1).topk(max_per_img)
            det_labels = indexes % self.num_classes
            bbox_index = indexes // self.num_classes
            bbox_pred = bbox_pred[bbox_index]
        else:
            scores, det_labels = F.softmax(cls_score, dim=-1)[..., :-1].max(-1)
            scores, bbox_index = scores.topk(max_per_img)
            bbox_pred = bbox_pred[bbox_index]
            det_labels = det_labels[bbox_index]

        det_bboxes = bbox_cxcywh_to_xyxy(bbox_pred)
        det_bboxes[:, 0::2] = det_bboxes[:, 0::2] * img_shape[1]
        det_bboxes[:, 1::2] = det_bboxes[:, 1::2] * img_shape[0]
        det_bboxes[:, 0::2].clamp_(min=0, max=img_shape[1])
        det_bboxes[:, 1::2].clamp_(min=0, max=img_shape[0])

        #lzx
        if self.use_nms:
            iou_threshold= 0.01
            offset = 0
            score_threshold = 0.0 # torch.mean(cls_score.view(-1))+3*torch.std(cls_score.view(-1))
            max_num = 300
            dets, inds = nms(det_bboxes, scores, iou_threshold, offset, score_threshold, max_num)
            det_bboxes = dets[:,:-1]
            scores = dets[:,-1]
            det_labels =det_labels[inds]



        # add by lzx
        if self.pre_bboxes_round:
            det_bboxes = adjust_bbox_to_pixel(det_bboxes)

        if rescale:
            # assert img_meta.get('scale_factor') is not None
            # det_bboxes /= det_bboxes.new_tensor(
            #     img_meta['scale_factor']).repeat((1, 2))
            # rw by lzx
            if img_meta.get('scale_factor') is not None:
                det_bboxes /= det_bboxes.new_tensor(
                    img_meta['scale_factor']).repeat((1, 2))
        results = InstanceData()
        results.bboxes = det_bboxes
        results.scores = scores
        results.labels = det_labels
        return results



    def loss_group(self, hidden_states: Tensor, references: List[Tensor],
             enc_outputs_class: Tensor, enc_outputs_coord: Tensor,
             batch_data_samples: SampleList, dn_meta: Dict[str, int],
             # match_group_size: Tuple[int, int] = (2, 2),
            each_match_num_queries: int = 200, ) -> dict:
        """Perform forward propagation and loss calculation of the detection
        head on the queries of the upstream network.

        Args:
            hidden_states (Tensor): Hidden states output from each decoder
                layer, has shape (num_decoder_layers, bs, num_queries_total,
                dim), where `num_queries_total` is the sum of
                `num_denoising_queries` and `num_matching_queries` when
                `self.training` is `True`, else `num_matching_queries`.
            references (list[Tensor]): List of the reference from the decoder.
                The first reference is the `init_reference` (initial) and the
                other num_decoder_layers(6) references are `inter_references`
                (intermediate). The `init_reference` has shape (bs,
                num_queries_total, 4) and each `inter_reference` has shape
                (bs, num_queries, 4) with the last dimension arranged as
                (cx, cy, w, h).
            enc_outputs_class (Tensor): The score of each point on encode
                feature map, has shape (bs, num_feat_points, cls_out_channels).
            enc_outputs_coord (Tensor): The proposal generate from the
                encode feature map, has shape (bs, num_feat_points, 4) with the
                last dimension arranged as (cx, cy, w, h).
            batch_data_samples (list[:obj:`DetDataSample`]): The Data
                Samples. It usually includes information such as
                `gt_instance`, `gt_panoptic_seg` and `gt_sem_seg`.
            dn_meta (Dict[str, int]): The dictionary saves information about
              group collation, including 'num_denoising_queries' and
              'num_denoising_groups'. It will be used for split outputs of
              denoising and matching parts and loss calculation.

        Returns:
            dict: A dictionary of loss components.
        """
        batch_gt_instances = []
        batch_img_metas = []
        for data_sample in batch_data_samples:
            batch_img_metas.append(data_sample.metainfo)
            batch_gt_instances.append(data_sample.gt_instances)

        outs = self(hidden_states, references)
        loss_inputs = outs + (enc_outputs_class, enc_outputs_coord,
                              batch_gt_instances, batch_img_metas, dn_meta,each_match_num_queries)
        losses = self.loss_by_feat_group(*loss_inputs)
        return losses

    def loss_by_feat_group(
        self,
        all_layers_cls_scores: Tensor,
        all_layers_bbox_preds: Tensor,
        enc_cls_scores: Tensor,
        enc_bbox_preds: Tensor,
        batch_gt_instances: InstanceList,
        batch_img_metas: List[dict],
        dn_meta: Dict[str, int],
        # match_group_size: Tuple[int, int] = (2, 2),
        each_match_num_queries: int = 200,
        batch_gt_instances_ignore: OptInstanceList = None,
    ) -> Dict[str, Tensor]:
        """Loss function.

        Args:
            all_layers_cls_scores (Tensor): Classification scores of all
                decoder layers, has shape (num_decoder_layers, bs,
                num_queries_total, cls_out_channels), where
                `num_queries_total` is the sum of `num_denoising_queries`
                and `num_matching_queries`.
            all_layers_bbox_preds (Tensor): Regression outputs of all decoder
                layers. Each is a 4D-tensor with normalized coordinate format
                (cx, cy, w, h) and has shape (num_decoder_layers, bs,
                num_queries_total, 4).
            enc_cls_scores (Tensor): The score of each point on encode
                feature map, has shape (bs, num_feat_points, cls_out_channels).
            enc_bbox_preds (Tensor): The proposal generate from the encode
                feature map, has shape (bs, num_feat_points, 4) with the last
                dimension arranged as (cx, cy, w, h).
            batch_gt_instances (list[:obj:`InstanceData`]): Batch of
                gt_instance. It usually includes ``bboxes`` and ``labels``
                attributes.
            batch_img_metas (list[dict]): Meta information of each image, e.g.,
                image size, scaling factor, etc.
            dn_meta (Dict[str, int]): The dictionary saves information about
                group collation, including 'num_denoising_queries' and
                'num_denoising_groups'. It will be used for split outputs of
                denoising and matching parts and loss calculation.
            batch_gt_instances_ignore (list[:obj:`InstanceData`], optional):
                Batch of gt_instances_ignore. It includes ``bboxes`` attribute
                data that is ignored during training and testing.
                Defaults to None.

        Returns:
            dict[str, Tensor]: A dictionary of loss components.
        """
        # extract denoising and matching part of outputs
        (all_layers_matching_cls_scores, all_layers_matching_bbox_preds,
         all_layers_denoising_cls_scores, all_layers_denoising_bbox_preds) = \
            self.split_outputs(
                all_layers_cls_scores, all_layers_bbox_preds, dn_meta)
        match_group_num = all_layers_matching_cls_scores.shape[2]//each_match_num_queries
        loss_dict = dict()
        for id_group in range(match_group_num):
            all_layers_matching_cls_scores_one_group = all_layers_matching_cls_scores[:, :, id_group * each_match_num_queries:(id_group + 1) * each_match_num_queries, :]
            all_layers_matching_bbox_preds_one_group =  all_layers_matching_bbox_preds[:, :, id_group * each_match_num_queries:(id_group + 1) * each_match_num_queries, :]
            # 同时计算每一解码层的loss
            losses_cls, losses_bbox, losses_iou = multi_apply(
                self.loss_by_feat_single,
                all_layers_matching_cls_scores_one_group,
                all_layers_matching_bbox_preds_one_group,
                batch_gt_instances=batch_gt_instances,
                batch_img_metas=batch_img_metas)
            # loss from the last decoder layer
            loss_dict[f'g{id_group}.loss_cls'] = losses_cls[-1]
            loss_dict[f'g{id_group}.loss_bbox'] = losses_bbox[-1]
            loss_dict[f'g{id_group}.loss_iou'] = losses_iou[-1]
            # loss from other decoder layers
            num_dec_layer = 0
            for loss_cls_i, loss_bbox_i, loss_iou_i in \
                    zip(losses_cls[:-1], losses_bbox[:-1], losses_iou[:-1]):
                loss_dict[f'g{id_group}d{num_dec_layer}.loss_cls'] = loss_cls_i
                loss_dict[f'g{id_group}d{num_dec_layer}.loss_bbox'] = loss_bbox_i
                loss_dict[f'g{id_group}d{num_dec_layer}.loss_iou'] = loss_iou_i
                num_dec_layer += 1


            # loss_dict_one_groug = super().loss_by_feat(all_layers_matching_cls_scores_one_group,  all_layers_matching_bbox_preds_one_group,
            #     batch_gt_instances, batch_img_metas, batch_gt_instances_ignore)
            enc_cls_scores_one_group = enc_cls_scores[:, id_group * each_match_num_queries:(id_group + 1) * each_match_num_queries, :]
            enc_bbox_preds_one_group = enc_bbox_preds[:, id_group * each_match_num_queries:(id_group + 1) * each_match_num_queries, :]
            if enc_cls_scores is not None:
                # NOTE The enc_loss calculation of the DINO is
                # different from that of Deformable DETR.
                enc_loss_cls, enc_losses_bbox, enc_losses_iou = \
                    self.loss_by_feat_single(enc_cls_scores_one_group,
                                             enc_bbox_preds_one_group,
                        batch_gt_instances=batch_gt_instances,
                        batch_img_metas=batch_img_metas)
                loss_dict[f'g{id_group}.enc_loss_cls'] = enc_loss_cls
                loss_dict[f'g{id_group}.enc_loss_bbox'] = enc_losses_bbox
                loss_dict[f'g{id_group}.enc_loss_iou'] = enc_losses_iou


        # loss_dict = super().loss_by_feat(
        #     all_layers_matching_cls_scores, all_layers_matching_bbox_preds,
        #     batch_gt_instances, batch_img_metas, batch_gt_instances_ignore)
        # # NOTE DETRHead.loss_by_feat but not DeformableDETRHead.loss_by_feat
        # # is called, because the encoder loss calculations are different
        # # between DINO and DeformableDETR.
        # # loss of proposal generated from encode feature map.
        # if enc_cls_scores is not None:
        #     # NOTE The enc_loss calculation of the DINO is
        #     # different from that of Deformable DETR.
        #     enc_loss_cls, enc_losses_bbox, enc_losses_iou = \
        #         self.loss_by_feat_single(
        #             enc_cls_scores, enc_bbox_preds,
        #             batch_gt_instances=batch_gt_instances,
        #             batch_img_metas=batch_img_metas)
        #     loss_dict['enc_loss_cls'] = enc_loss_cls
        #     loss_dict['enc_loss_bbox'] = enc_losses_bbox
        #     loss_dict['enc_loss_iou'] = enc_losses_iou

        if all_layers_denoising_cls_scores is not None:
            # calculate denoising loss from all decoder layers
            dn_losses_cls, dn_losses_bbox, dn_losses_iou = self.loss_dn(
                all_layers_denoising_cls_scores,
                all_layers_denoising_bbox_preds,
                batch_gt_instances=batch_gt_instances,
                batch_img_metas=batch_img_metas,
                dn_meta=dn_meta)
            # collate denoising loss
            loss_dict['dn_loss_cls'] = dn_losses_cls[-1]
            loss_dict['dn_loss_bbox'] = dn_losses_bbox[-1]
            loss_dict['dn_loss_iou'] = dn_losses_iou[-1]
            for num_dec_layer, (loss_cls_i, loss_bbox_i, loss_iou_i) in \
                    enumerate(zip(dn_losses_cls[:-1], dn_losses_bbox[:-1],
                                  dn_losses_iou[:-1])):
                loss_dict[f'd{num_dec_layer}.dn_loss_cls'] = loss_cls_i
                loss_dict[f'd{num_dec_layer}.dn_loss_bbox'] = loss_bbox_i
                loss_dict[f'd{num_dec_layer}.dn_loss_iou'] = loss_iou_i
        return loss_dict

    def loss_ddn(self, hidden_states: Tensor, references: List[Tensor],
             enc_outputs_class: Tensor, enc_outputs_coord: Tensor,
             batch_data_samples: SampleList, dn_meta: Dict[str, int]) -> dict:
        """Perform forward propagation and loss calculation of the detection
        head on the queries of the upstream network.

        Args:
            hidden_states (Tensor): Hidden states output from each decoder
                layer, has shape (num_decoder_layers, bs, num_queries_total,
                dim), where `num_queries_total` is the sum of
                `num_denoising_queries` and `num_matching_queries` when
                `self.training` is `True`, else `num_matching_queries`.
            references (list[Tensor]): List of the reference from the decoder.
                The first reference is the `init_reference` (initial) and the
                other num_decoder_layers(6) references are `inter_references`
                (intermediate). The `init_reference` has shape (bs,
                num_queries_total, 4) and each `inter_reference` has shape
                (bs, num_queries, 4) with the last dimension arranged as
                (cx, cy, w, h).
            enc_outputs_class (Tensor): The score of each point on encode
                feature map, has shape (bs, num_feat_points, cls_out_channels).
            enc_outputs_coord (Tensor): The proposal generate from the
                encode feature map, has shape (bs, num_feat_points, 4) with the
                last dimension arranged as (cx, cy, w, h).
            batch_data_samples (list[:obj:`DetDataSample`]): The Data
                Samples. It usually includes information such as
                `gt_instance`, `gt_panoptic_seg` and `gt_sem_seg`.
            dn_meta (Dict[str, int]): The dictionary saves information about
              group collation, including 'num_denoising_queries' and
              'num_denoising_groups'. It will be used for split outputs of
              denoising and matching parts and loss calculation.

        Returns:
            dict: A dictionary of loss components.
        """
        batch_gt_instances = []
        batch_img_metas = []
        for data_sample in batch_data_samples:
            batch_img_metas.append(data_sample.metainfo)
            batch_gt_instances.append(data_sample.gt_instances)

        outs = self(hidden_states, references)
        loss_inputs = outs + (enc_outputs_class, enc_outputs_coord,
                              batch_gt_instances, batch_img_metas, dn_meta)
        losses,pos_bbox_offsets = self.loss_ddn_by_feat(*loss_inputs)
        return losses,pos_bbox_offsets

    def loss_ddn_by_feat(
        self,
        all_layers_cls_scores: Tensor,
        all_layers_bbox_preds: Tensor,
        enc_cls_scores: Tensor,
        enc_bbox_preds: Tensor,
        batch_gt_instances: InstanceList,
        batch_img_metas: List[dict],
        dn_meta: Dict[str, int],
        # match_group_size: Tuple[int, int] = (2, 2),
        batch_gt_instances_ignore: OptInstanceList = None,
    ) ->  Tuple[Dict[str, Tensor], List]:
        """Loss function.

        Args:
            all_layers_cls_scores (Tensor): Classification scores of all
                decoder layers, has shape (num_decoder_layers, bs,
                num_queries_total, cls_out_channels), where
                `num_queries_total` is the sum of `num_denoising_queries`
                and `num_matching_queries`.
            all_layers_bbox_preds (Tensor): Regression outputs of all decoder
                layers. Each is a 4D-tensor with normalized coordinate format
                (cx, cy, w, h) and has shape (num_decoder_layers, bs,
                num_queries_total, 4).
            enc_cls_scores (Tensor): The score of each point on encode
                feature map, has shape (bs, num_feat_points, cls_out_channels).
            enc_bbox_preds (Tensor): The proposal generate from the encode
                feature map, has shape (bs, num_feat_points, 4) with the last
                dimension arranged as (cx, cy, w, h).
            batch_gt_instances (list[:obj:`InstanceData`]): Batch of
                gt_instance. It usually includes ``bboxes`` and ``labels``
                attributes.
            batch_img_metas (list[dict]): Meta information of each image, e.g.,
                image size, scaling factor, etc.
            dn_meta (Dict[str, int]): The dictionary saves information about
                group collation, including 'num_denoising_queries' and
                'num_denoising_groups'. It will be used for split outputs of
                denoising and matching parts and loss calculation.
            batch_gt_instances_ignore (list[:obj:`InstanceData`], optional):
                Batch of gt_instances_ignore. It includes ``bboxes`` attribute
                data that is ignored during training and testing.
                Defaults to None.

        Returns:
            dict[str, Tensor]: A dictionary of loss components.
        """
        # extract denoising and matching part of outputs
        (all_layers_matching_cls_scores, all_layers_matching_bbox_preds,
         all_layers_denoising_cls_scores, all_layers_denoising_bbox_preds) = \
            self.split_outputs(
                all_layers_cls_scores, all_layers_bbox_preds, dn_meta)
        loss_dict = dict()

        assert batch_gt_instances_ignore is None, \
            f'{self.__class__.__name__} only supports ' \
            'for batch_gt_instances_ignore setting to None.'
        #同时计算每一解码层的loss
        losses_cls, losses_bbox, losses_iou, pos_bbox_offsets = multi_apply(
            self.loss_ddn_by_feat_single,
            all_layers_matching_cls_scores,
            all_layers_matching_bbox_preds,
            batch_gt_instances=batch_gt_instances,
            batch_img_metas=batch_img_metas)
        # loss from the last decoder layer
        loss_dict['loss_cls'] = losses_cls[-1]
        loss_dict['loss_bbox'] = losses_bbox[-1]
        loss_dict['loss_iou'] = losses_iou[-1]
        # loss from other decoder layers
        num_dec_layer = 0
        for loss_cls_i, loss_bbox_i, loss_iou_i in \
                zip(losses_cls[:-1], losses_bbox[:-1], losses_iou[:-1]):
            loss_dict[f'd{num_dec_layer}.loss_cls'] = loss_cls_i
            loss_dict[f'd{num_dec_layer}.loss_bbox'] = loss_bbox_i
            loss_dict[f'd{num_dec_layer}.loss_iou'] = loss_iou_i
            num_dec_layer += 1

        # NOTE DETRHead.loss_by_feat but not DeformableDETRHead.loss_by_feat
        # is called, because the encoder loss calculations are different
        # between DINO and DeformableDETR.
        # loss of proposal generated from encode feature map.
        if enc_cls_scores is not None:
            # NOTE The enc_loss calculation of the DINO is
            # different from that of Deformable DETR.
            enc_loss_cls, enc_losses_bbox, enc_losses_iou, pos_bbox_offsets = \
                self.loss_ddn_by_feat_single(
                    enc_cls_scores, enc_bbox_preds,
                    batch_gt_instances=batch_gt_instances,
                    batch_img_metas=batch_img_metas)
            loss_dict['enc_loss_cls'] = enc_loss_cls
            loss_dict['enc_loss_bbox'] = enc_losses_bbox
            loss_dict['enc_loss_iou'] = enc_losses_iou

        if all_layers_denoising_cls_scores is not None:
            # calculate denoising loss from all decoder layers
            dn_losses_cls, dn_losses_bbox, dn_losses_iou = self.loss_dn(
                all_layers_denoising_cls_scores,
                all_layers_denoising_bbox_preds,
                batch_gt_instances=batch_gt_instances,
                batch_img_metas=batch_img_metas,
                dn_meta=dn_meta)
            # collate denoising loss
            loss_dict['dn_loss_cls'] = dn_losses_cls[-1]
            loss_dict['dn_loss_bbox'] = dn_losses_bbox[-1]
            loss_dict['dn_loss_iou'] = dn_losses_iou[-1]
            for num_dec_layer, (loss_cls_i, loss_bbox_i, loss_iou_i) in \
                    enumerate(zip(dn_losses_cls[:-1], dn_losses_bbox[:-1],
                                  dn_losses_iou[:-1])):
                loss_dict[f'd{num_dec_layer}.dn_loss_cls'] = loss_cls_i
                loss_dict[f'd{num_dec_layer}.dn_loss_bbox'] = loss_bbox_i
                loss_dict[f'd{num_dec_layer}.dn_loss_iou'] = loss_iou_i
        return loss_dict, pos_bbox_offsets


    def loss_ddn_by_feat_single(self, cls_scores: Tensor, bbox_preds: Tensor,
                            batch_gt_instances: InstanceList,
                            batch_img_metas: List[dict]) -> Tuple[Tensor, List]:
        """Loss function for outputs from a single decoder layer of a single
        feature level.

        Args:
            cls_scores (Tensor): Box score logits from a single decoder layer
                for all images, has shape (bs, num_queries, cls_out_channels).
            bbox_preds (Tensor): Sigmoid outputs from a single decoder layer
                for all images, with normalized coordinate (cx, cy, w, h) and
                shape (bs, num_queries, 4).
            batch_gt_instances (list[:obj:`InstanceData`]): Batch of
                gt_instance. It usually includes ``bboxes`` and ``labels``
                attributes.
            batch_img_metas (list[dict]): Meta information of each image, e.g.,
                image size, scaling factor, etc.

        Returns:
            Tuple[Tensor]: A tuple including `loss_cls`, `loss_box` and
            `loss_iou`.
        """
        num_imgs = cls_scores.size(0)
        cls_scores_list = [cls_scores[i] for i in range(num_imgs)]
        bbox_preds_list = [bbox_preds[i] for i in range(num_imgs)]
        cls_reg_targets = self.get_targets_ddn(cls_scores_list, bbox_preds_list,
                                           batch_gt_instances, batch_img_metas)
        (labels_list, label_weights_list, bbox_targets_list, bbox_weights_list,
         num_total_pos, num_total_neg) = cls_reg_targets
        labels = torch.cat(labels_list, 0)
        label_weights = torch.cat(label_weights_list, 0)
        bbox_targets = torch.cat(bbox_targets_list, 0)
        bbox_weights = torch.cat(bbox_weights_list, 0)

        # classification loss
        cls_scores = cls_scores.reshape(-1, self.cls_out_channels)
        # construct weighted avg_factor to match with the official DETR repo
        cls_avg_factor = num_total_pos * 1.0 + \
            num_total_neg * self.bg_cls_weight
        if self.sync_cls_avg_factor:
            cls_avg_factor = reduce_mean(
                cls_scores.new_tensor([cls_avg_factor]))
        cls_avg_factor = max(cls_avg_factor, 1)

        loss_cls = self.loss_cls(
            cls_scores, labels, label_weights, avg_factor=cls_avg_factor)

        # Compute the average number of gt boxes across all gpus, for
        # normalization purposes
        num_total_pos = loss_cls.new_tensor([num_total_pos])
        num_total_pos = torch.clamp(reduce_mean(num_total_pos), min=1).item()

        # construct factors used for rescale bboxes
        factors = []
        for img_meta, bbox_pred in zip(batch_img_metas, bbox_preds):
            img_h, img_w, = img_meta['img_shape']
            factor = bbox_pred.new_tensor([img_w, img_h, img_w,
                                           img_h]).unsqueeze(0).repeat(
                                               bbox_pred.size(0), 1)
            factors.append(factor)
        factors = torch.cat(factors, 0)

        # DETR regress the relative position of boxes (cxcywh) in the image,
        # thus the learning target is normalized by the image size. So here
        # we need to re-scale them for calculating IoU loss
        bbox_preds = bbox_preds.reshape(-1, 4)
        bboxes = bbox_cxcywh_to_xyxy(bbox_preds) * factors
        bboxes_gt = bbox_cxcywh_to_xyxy(bbox_targets) * factors


        # lzx
        # 检查bbox_targets中4个值是否全部为0
        is_target = torch.any(bbox_targets != 0, dim=1)
        # 获取目标的索引
        target_indices = torch.nonzero(is_target).squeeze()
        bbox_targets_only_pos = bbox_targets[target_indices]
        bbox_preds_only_pos = bbox_preds[target_indices]
        # factors_only_pos = factors[target_indices]
        pos_bbox_offset = torch.mean(torch.abs(bbox_targets_only_pos-bbox_preds_only_pos),dim=0).detach().cpu().numpy()
        pos_bbox_offsets = [(pos_bbox_offset[0]+pos_bbox_offset[1])/2,(pos_bbox_offset[2]+pos_bbox_offset[3])/2]
        # regression IoU loss, defaultly GIoU loss
        loss_iou = self.loss_iou(
            bboxes, bboxes_gt, bbox_weights, avg_factor=num_total_pos)

        # regression L1 loss
        loss_bbox = self.loss_bbox(
            bbox_preds, bbox_targets, bbox_weights, avg_factor=num_total_pos)
        return loss_cls, loss_bbox, loss_iou, pos_bbox_offsets

    def get_targets_ddn(self, cls_scores_list: List[Tensor],
                    bbox_preds_list: List[Tensor],
                    batch_gt_instances: InstanceList,
                    batch_img_metas: List[dict]) -> tuple:
        """Compute regression and classification targets for a batch image.

        Outputs from a single decoder layer of a single feature level are used.

        Args:
            cls_scores_list (list[Tensor]): Box score logits from a single
                decoder layer for each image, has shape [num_queries,
                cls_out_channels].
            bbox_preds_list (list[Tensor]): Sigmoid outputs from a single
                decoder layer for each image, with normalized coordinate
                (cx, cy, w, h) and shape [num_queries, 4].
            batch_gt_instances (list[:obj:`InstanceData`]): Batch of
                gt_instance. It usually includes ``bboxes`` and ``labels``
                attributes.
            batch_img_metas (list[dict]): Meta information of each image, e.g.,
                image size, scaling factor, etc.

        Returns:
            tuple: a tuple containing the following targets.

            - labels_list (list[Tensor]): Labels for all images.
            - label_weights_list (list[Tensor]): Label weights for all images.
            - bbox_targets_list (list[Tensor]): BBox targets for all images.
            - bbox_weights_list (list[Tensor]): BBox weights for all images.
            - num_total_pos (int): Number of positive samples in all images.
            - num_total_neg (int): Number of negative samples in all images.
        """
        (labels_list, label_weights_list, bbox_targets_list, bbox_weights_list,
         pos_inds_list,
         neg_inds_list) = multi_apply(self._get_targets_single_ddn,
                                      cls_scores_list, bbox_preds_list,
                                      batch_gt_instances, batch_img_metas)
        num_total_pos = sum((inds.numel() for inds in pos_inds_list))
        num_total_neg = sum((inds.numel() for inds in neg_inds_list))
        return (labels_list, label_weights_list, bbox_targets_list,
                bbox_weights_list, num_total_pos, num_total_neg)

    def _get_targets_single_ddn(self, cls_score: Tensor, bbox_pred: Tensor,
                            gt_instances: InstanceData,
                            img_meta: dict) -> tuple:
        """Compute regression and classification targets for one image.

        Outputs from a single decoder layer of a single feature level are used.

        Args:
            cls_score (Tensor): Box score logits from a single decoder layer
                for one image. Shape [num_queries, cls_out_channels].
            bbox_pred (Tensor): Sigmoid outputs from a single decoder layer
                for one image, with normalized coordinate (cx, cy, w, h) and
                shape [num_queries, 4].
            gt_instances (:obj:`InstanceData`): Ground truth of instance
                annotations. It should includes ``bboxes`` and ``labels``
                attributes.
            img_meta (dict): Meta information for one image.

        Returns:
            tuple[Tensor]: a tuple containing the following for one image.

            - labels (Tensor): Labels of each image.
            - label_weights (Tensor]): Label weights of each image.
            - bbox_targets (Tensor): BBox targets of each image.
            - bbox_weights (Tensor): BBox weights of each image.
            - pos_inds (Tensor): Sampled positive indices for each image.
            - neg_inds (Tensor): Sampled negative indices for each image.
        """
        img_h, img_w = img_meta['img_shape']
        factor = bbox_pred.new_tensor([img_w, img_h, img_w,
                                       img_h]).unsqueeze(0)
        num_bboxes = bbox_pred.size(0)
        # convert bbox_pred from xywh, normalized to xyxy, unnormalized
        bbox_pred = bbox_cxcywh_to_xyxy(bbox_pred)
        bbox_pred = bbox_pred * factor

        pred_instances = InstanceData(scores=cls_score, bboxes=bbox_pred)
        # assigner and sampler
        assign_result = self.assigner.assign(
            pred_instances=pred_instances,
            gt_instances=gt_instances,
            img_meta=img_meta)

        # from mmdet.models.task_modules.assigners import MaxIoUAssigner
        # assigner1 = MaxIoUAssigner(pos_iou_thr=0.5, neg_iou_thr=0.5, min_pos_iou=0.3,match_low_quality=True,ignore_iof_thr=-1)
        # pred_instances1 = InstanceData()
        # pred_instances1.priors =pred_instances.bboxes
        # assign_result = assigner1.assign(pred_instances=pred_instances1,  gt_instances=gt_instances,   img_meta=img_meta)


        gt_bboxes = gt_instances.bboxes
        gt_labels = gt_instances.labels
        pos_inds = torch.nonzero(
            assign_result.gt_inds > 0, as_tuple=False).squeeze(-1).unique()
        neg_inds = torch.nonzero(
            assign_result.gt_inds == 0, as_tuple=False).squeeze(-1).unique()
        pos_assigned_gt_inds = assign_result.gt_inds[pos_inds] - 1
        pos_gt_bboxes = gt_bboxes[pos_assigned_gt_inds.long(), :]

        # label targets
        labels = gt_bboxes.new_full((num_bboxes, ),
                                    self.num_classes,
                                    dtype=torch.long)
        labels[pos_inds] = gt_labels[pos_assigned_gt_inds]
        label_weights = gt_bboxes.new_ones(num_bboxes)

        # bbox targets
        bbox_targets = torch.zeros_like(bbox_pred)
        bbox_weights = torch.zeros_like(bbox_pred)
        bbox_weights[pos_inds] = 1.0

        # DETR regress the relative position of boxes (cxcywh) in the image.
        # Thus the learning target should be normalized by the image size, also
        # the box format should be converted from defaultly x1y1x2y2 to cxcywh.
        pos_gt_bboxes_normalized = pos_gt_bboxes / factor
        pos_gt_bboxes_targets = bbox_xyxy_to_cxcywh(pos_gt_bboxes_normalized)
        bbox_targets[pos_inds] = pos_gt_bboxes_targets
        return (labels, label_weights, bbox_targets, bbox_weights, pos_inds,
                neg_inds)