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First model version
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# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
"""
Implements the Generalized R-CNN framework
"""
import torch
from torch import nn
from maskrcnn_benchmark.structures.image_list import to_image_list
from ..backbone import build_backbone
from ..rpn.rpn import build_rpn
from ..roi_heads.roi_heads import build_roi_heads
import numpy as np
import cv2
class GeneralizedRCNN(nn.Module):
"""
Main class for Generalized R-CNN. Currently supports boxes and masks.
It consists of three main parts:
- backbone
- rpn
- heads: takes the features + the proposals from the RPN and computes
detections / masks from it.
"""
def __init__(self, cfg):
super(GeneralizedRCNN, self).__init__()
self.cfg = cfg.clone()
self.backbone = build_backbone(cfg)
self.rpn = build_rpn(cfg, self.backbone.out_channels)
self.roi_heads = build_roi_heads(cfg, self.backbone.out_channels)
def forward(self, images, targets=None):
"""
Arguments:
images (list[Tensor] or ImageList): images to be processed
targets (list[BoxList]): ground-truth boxes present in the image (optional)
Returns:
result (list[BoxList] or dict[Tensor]): the output from the model.
During training, it returns a dict[Tensor] which contains the losses.
During testing, it returns list[BoxList] contains additional fields
like `scores`, `labels` and `mask` (for Mask R-CNN models).
"""
if self.training and targets is None:
raise ValueError("In training mode, targets should be passed")
images = to_image_list(images)
features = self.backbone(images.tensors)
proposals, proposal_losses = self.rpn(images, features, targets)
if self.roi_heads:
x, result, detector_losses = self.roi_heads(features, proposals, targets)
else:
#self.warm_start -= 1
# RPN-only models don't have roi_heads
x = features
result = proposals
detector_losses = {}
if self.training:
losses = {}
losses.update(detector_losses)
losses.update(proposal_losses)
return losses
else:
return result