Spaces:
Sleeping
Sleeping
File size: 2,970 Bytes
749745d |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 |
# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
import torch
from torch import nn
from .roi_box_feature_extractors import make_roi_box_feature_extractor
from .roi_box_predictors import make_roi_box_predictor
from .inference import make_roi_box_post_processor
from .loss import make_roi_box_loss_evaluator
from maskrcnn_benchmark.utils.amp import custom_fwd, custom_bwd
class ROIBoxHead(torch.nn.Module):
"""
Generic Box Head class.
"""
def __init__(self, cfg):
super(ROIBoxHead, self).__init__()
self.feature_extractor = make_roi_box_feature_extractor(cfg)
self.predictor = make_roi_box_predictor(cfg)
self.post_processor = make_roi_box_post_processor(cfg)
self.loss_evaluator = make_roi_box_loss_evaluator(cfg)
self.onnx = cfg.MODEL.ONNX
@custom_fwd(cast_inputs=torch.float32)
def forward(self, features, proposals, targets=None):
"""
Arguments:
features (list[Tensor]): feature-maps from possibly several levels
proposals (list[BoxList]): proposal boxes
targets (list[BoxList], optional): the ground-truth targets.
Returns:
x (Tensor): the result of the feature extractor
proposals (list[BoxList]): during training, the subsampled proposals
are returned. During testing, the predicted boxlists are returned
losses (dict[Tensor]): During training, returns the losses for the
head. During testing, returns an empty dict.
"""
if self.training:
# Faster R-CNN subsamples during training the proposals with a fixed
# positive / negative ratio
with torch.no_grad():
proposals = self.loss_evaluator.subsample(proposals, targets)
# extract features that will be fed to the final classifier. The
# feature_extractor generally corresponds to the pooler + heads
x = self.feature_extractor(features, proposals)
# final classifier that converts the features into predictions
class_logits, box_regression = self.predictor(x)
if self.onnx:
return x, (class_logits, box_regression, [box.bbox for box in proposals]), {}
if not self.training:
result = self.post_processor((class_logits, box_regression), proposals)
return x, result, {}
loss_classifier, loss_box_reg = self.loss_evaluator([class_logits], [box_regression])
return (
x,
proposals,
dict(loss_classifier=loss_classifier, loss_box_reg=loss_box_reg),
)
def build_roi_box_head(cfg):
"""
Constructs a new box head.
By default, uses ROIBoxHead, but if it turns out not to be enough, just register a new class
and make it a parameter in the config
"""
return ROIBoxHead(cfg)
|