Spaces:
Runtime error
Runtime error
# Copyright (c) OpenMMLab. All rights reserved. | |
import torch.nn as nn | |
from mmcv.cnn import ConvModule | |
from mmcv.runner import BaseModule | |
from mmocr.models.builder import BACKBONES | |
class ShallowCNN(BaseModule): | |
"""Implement Shallow CNN block for SATRN. | |
SATRN: `On Recognizing Texts of Arbitrary Shapes with 2D Self-Attention | |
<https://arxiv.org/pdf/1910.04396.pdf>`_. | |
Args: | |
base_channels (int): Number of channels of input image tensor | |
:math:`D_i`. | |
hidden_dim (int): Size of hidden layers of the model :math:`D_m`. | |
init_cfg (dict or list[dict], optional): Initialization configs. | |
""" | |
def __init__(self, | |
input_channels=1, | |
hidden_dim=512, | |
init_cfg=[ | |
dict(type='Kaiming', layer='Conv2d'), | |
dict(type='Uniform', layer='BatchNorm2d') | |
]): | |
super().__init__(init_cfg=init_cfg) | |
assert isinstance(input_channels, int) | |
assert isinstance(hidden_dim, int) | |
self.conv1 = ConvModule( | |
input_channels, | |
hidden_dim // 2, | |
kernel_size=3, | |
stride=1, | |
padding=1, | |
bias=False, | |
norm_cfg=dict(type='BN'), | |
act_cfg=dict(type='ReLU')) | |
self.conv2 = ConvModule( | |
hidden_dim // 2, | |
hidden_dim, | |
kernel_size=3, | |
stride=1, | |
padding=1, | |
bias=False, | |
norm_cfg=dict(type='BN'), | |
act_cfg=dict(type='ReLU')) | |
self.pool = nn.MaxPool2d(kernel_size=2, stride=2, padding=0) | |
def forward(self, x): | |
""" | |
Args: | |
x (Tensor): Input image feature :math:`(N, D_i, H, W)`. | |
Returns: | |
Tensor: A tensor of shape :math:`(N, D_m, H/4, W/4)`. | |
""" | |
x = self.conv1(x) | |
x = self.pool(x) | |
x = self.conv2(x) | |
x = self.pool(x) | |
return x | |