115 lines
4.0 KiB
Python
115 lines
4.0 KiB
Python
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#!/usr/bin/env python3
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# -*- coding: utf-8 -*-
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import math
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import torch.nn as nn
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import torch.nn.functional as F
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class SRVGGNetCompact(nn.Module):
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"""A compact VGG-style network structure for super-resolution.
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It is a compact network structure, which performs upsampling in the last layer and no convolution is
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conducted on the HR feature space.
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Args:
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num_in_ch (int): Channel number of inputs. Default: 3.
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num_out_ch (int): Channel number of outputs. Default: 3.
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num_feat (int): Channel number of intermediate features. Default: 64.
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num_conv (int): Number of convolution layers in the body network. Default: 16.
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upscale (int): Upsampling factor. Default: 4.
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act_type (str): Activation type, options: 'relu', 'prelu', 'leakyrelu'. Default: prelu.
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"""
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def __init__(
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self,
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state_dict,
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act_type: str = "prelu",
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):
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super(SRVGGNetCompact, self).__init__()
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self.model_arch = "SRVGG (RealESRGAN)"
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self.sub_type = "SR"
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self.act_type = act_type
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self.state = state_dict
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if "params" in self.state:
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self.state = self.state["params"]
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self.key_arr = list(self.state.keys())
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self.in_nc = self.get_in_nc()
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self.num_feat = self.get_num_feats()
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self.num_conv = self.get_num_conv()
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self.out_nc = self.in_nc # :(
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self.pixelshuffle_shape = None # Defined in get_scale()
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self.scale = self.get_scale()
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self.supports_fp16 = True
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self.supports_bfp16 = True
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self.min_size_restriction = None
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self.body = nn.ModuleList()
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# the first conv
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self.body.append(nn.Conv2d(self.in_nc, self.num_feat, 3, 1, 1))
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# the first activation
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if act_type == "relu":
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activation = nn.ReLU(inplace=True)
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elif act_type == "prelu":
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activation = nn.PReLU(num_parameters=self.num_feat)
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elif act_type == "leakyrelu":
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activation = nn.LeakyReLU(negative_slope=0.1, inplace=True)
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self.body.append(activation) # type: ignore
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# the body structure
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for _ in range(self.num_conv):
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self.body.append(nn.Conv2d(self.num_feat, self.num_feat, 3, 1, 1))
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# activation
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if act_type == "relu":
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activation = nn.ReLU(inplace=True)
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elif act_type == "prelu":
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activation = nn.PReLU(num_parameters=self.num_feat)
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elif act_type == "leakyrelu":
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activation = nn.LeakyReLU(negative_slope=0.1, inplace=True)
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self.body.append(activation) # type: ignore
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# the last conv
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self.body.append(nn.Conv2d(self.num_feat, self.pixelshuffle_shape, 3, 1, 1)) # type: ignore
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# upsample
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self.upsampler = nn.PixelShuffle(self.scale)
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self.load_state_dict(self.state, strict=False)
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def get_num_conv(self) -> int:
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return (int(self.key_arr[-1].split(".")[1]) - 2) // 2
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def get_num_feats(self) -> int:
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return self.state[self.key_arr[0]].shape[0]
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def get_in_nc(self) -> int:
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return self.state[self.key_arr[0]].shape[1]
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def get_scale(self) -> int:
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self.pixelshuffle_shape = self.state[self.key_arr[-1]].shape[0]
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# Assume out_nc is the same as in_nc
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# I cant think of a better way to do that
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self.out_nc = self.in_nc
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scale = math.sqrt(self.pixelshuffle_shape / self.out_nc)
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if scale - int(scale) > 0:
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print(
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"out_nc is probably different than in_nc, scale calculation might be wrong"
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)
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scale = int(scale)
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return scale
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def forward(self, x):
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out = x
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for i in range(0, len(self.body)):
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out = self.body[i](out)
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out = self.upsampler(out)
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# add the nearest upsampled image, so that the network learns the residual
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base = F.interpolate(x, scale_factor=self.scale, mode="nearest")
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out += base
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return out
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