Spaces:
Runtime error
Runtime error
# Copyright (c) OpenMMLab. All rights reserved. | |
from typing import List, Tuple | |
import torch | |
import torch.nn as nn | |
import torch.nn.functional as F | |
from mmengine.model import BaseModule | |
try: | |
from mmdet.models.dense_heads import MaskFormerHead as MMDET_MaskFormerHead | |
except ModuleNotFoundError: | |
MMDET_MaskFormerHead = BaseModule | |
from mmengine.structures import InstanceData | |
from torch import Tensor | |
from mmseg.registry import MODELS | |
from mmseg.structures.seg_data_sample import SegDataSample | |
from mmseg.utils import ConfigType, SampleList | |
class MaskFormerHead(MMDET_MaskFormerHead): | |
"""Implements the MaskFormer head. | |
See `Per-Pixel Classification is Not All You Need for Semantic Segmentation | |
<https://arxiv.org/pdf/2107.06278>`_ for details. | |
Args: | |
num_classes (int): Number of classes. Default: 150. | |
align_corners (bool): align_corners argument of F.interpolate. | |
Default: False. | |
ignore_index (int): The label index to be ignored. Default: 255. | |
""" | |
def __init__(self, | |
num_classes: int = 150, | |
align_corners: bool = False, | |
ignore_index: int = 255, | |
**kwargs) -> None: | |
super().__init__(**kwargs) | |
self.out_channels = kwargs['out_channels'] | |
self.align_corners = True | |
self.num_classes = num_classes | |
self.align_corners = align_corners | |
self.out_channels = num_classes | |
self.ignore_index = ignore_index | |
feat_channels = kwargs['feat_channels'] | |
self.cls_embed = nn.Linear(feat_channels, self.num_classes + 1) | |
def _seg_data_to_instance_data(self, batch_data_samples: SampleList): | |
"""Perform forward propagation to convert paradigm from MMSegmentation | |
to MMDetection to ensure ``MMDET_MaskFormerHead`` could be called | |
normally. Specifically, ``batch_gt_instances`` would be added. | |
Args: | |
batch_data_samples (List[:obj:`SegDataSample`]): The Data | |
Samples. It usually includes information such as | |
`gt_sem_seg`. | |
Returns: | |
tuple[Tensor]: A tuple contains two lists. | |
- batch_gt_instances (list[:obj:`InstanceData`]): Batch of | |
gt_instance. It usually includes ``labels``, each is | |
unique ground truth label id of images, with | |
shape (num_gt, ) and ``masks``, each is ground truth | |
masks of each instances of a image, shape (num_gt, h, w). | |
- batch_img_metas (list[dict]): List of image meta information. | |
""" | |
batch_img_metas = [] | |
batch_gt_instances = [] | |
for data_sample in batch_data_samples: | |
# Add `batch_input_shape` in metainfo of data_sample, which would | |
# be used in MaskFormerHead of MMDetection. | |
metainfo = data_sample.metainfo | |
metainfo['batch_input_shape'] = metainfo['img_shape'] | |
data_sample.set_metainfo(metainfo) | |
batch_img_metas.append(data_sample.metainfo) | |
gt_sem_seg = data_sample.gt_sem_seg.data | |
classes = torch.unique( | |
gt_sem_seg, | |
sorted=False, | |
return_inverse=False, | |
return_counts=False) | |
# remove ignored region | |
gt_labels = classes[classes != self.ignore_index] | |
masks = [] | |
for class_id in gt_labels: | |
masks.append(gt_sem_seg == class_id) | |
if len(masks) == 0: | |
gt_masks = torch.zeros((0, gt_sem_seg.shape[-2], | |
gt_sem_seg.shape[-1])).to(gt_sem_seg) | |
else: | |
gt_masks = torch.stack(masks).squeeze(1) | |
instance_data = InstanceData( | |
labels=gt_labels, masks=gt_masks.long()) | |
batch_gt_instances.append(instance_data) | |
return batch_gt_instances, batch_img_metas | |
def loss(self, x: Tuple[Tensor], batch_data_samples: SampleList, | |
train_cfg: ConfigType) -> dict: | |
"""Perform forward propagation and loss calculation of the decoder head | |
on the features of the upstream network. | |
Args: | |
x (tuple[Tensor]): Multi-level features from the upstream | |
network, each is a 4D-tensor. | |
batch_data_samples (List[:obj:`SegDataSample`]): The Data | |
Samples. It usually includes information such as | |
`gt_sem_seg`. | |
train_cfg (ConfigType): Training config. | |
Returns: | |
dict[str, Tensor]: a dictionary of loss components. | |
""" | |
# batch SegDataSample to InstanceDataSample | |
batch_gt_instances, batch_img_metas = self._seg_data_to_instance_data( | |
batch_data_samples) | |
# forward | |
all_cls_scores, all_mask_preds = self(x, batch_data_samples) | |
# loss | |
losses = self.loss_by_feat(all_cls_scores, all_mask_preds, | |
batch_gt_instances, batch_img_metas) | |
return losses | |
def predict(self, x: Tuple[Tensor], batch_img_metas: List[dict], | |
test_cfg: ConfigType) -> Tuple[Tensor]: | |
"""Test without augmentaton. | |
Args: | |
x (tuple[Tensor]): Multi-level features from the | |
upstream network, each is a 4D-tensor. | |
batch_img_metas (List[:obj:`SegDataSample`]): The Data | |
Samples. It usually includes information such as | |
`gt_sem_seg`. | |
test_cfg (ConfigType): Test config. | |
Returns: | |
Tensor: A tensor of segmentation mask. | |
""" | |
batch_data_samples = [] | |
for metainfo in batch_img_metas: | |
metainfo['batch_input_shape'] = metainfo['img_shape'] | |
batch_data_samples.append(SegDataSample(metainfo=metainfo)) | |
# Forward function of MaskFormerHead from MMDetection needs | |
# 'batch_data_samples' as inputs, which is image shape actually. | |
all_cls_scores, all_mask_preds = self(x, batch_data_samples) | |
mask_cls_results = all_cls_scores[-1] | |
mask_pred_results = all_mask_preds[-1] | |
# upsample masks | |
img_shape = batch_img_metas[0]['batch_input_shape'] | |
mask_pred_results = F.interpolate( | |
mask_pred_results, | |
size=img_shape, | |
mode='bilinear', | |
align_corners=False) | |
# semantic inference | |
cls_score = F.softmax(mask_cls_results, dim=-1)[..., :-1] | |
mask_pred = mask_pred_results.sigmoid() | |
seg_logits = torch.einsum('bqc,bqhw->bchw', cls_score, mask_pred) | |
return seg_logits | |