code: def forward(self, f, targets=None):
      out = self.conv1(f)
      out = self.relu1(self.bn1(out))
      out = self.conv2(out)
  
      if self.training:
          out = self._upsample(out, scale=4)
          return {"maps": out}
      else:
          score = F.sigmoid(out[:, 0, :, :])
          return {"maps": out, "score": score}
  
file_path: PaddleOCR/ppocr/modeling/heads/det_ct_head.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import math
  import paddle
  from paddle import nn
  import paddle.nn.functional
  from paddle import ParamAttr
  import math
  from paddle.nn.initializer import TruncatedNormal, Constant, Normal
label_desc: Use image node_id 3 for calling the CT_Head obj's underlying member method code with example usage: obj.forward(f, targets) and returns: dict, dict