diff --git a/codes/models/archs/multi_res_rrdb.py b/codes/models/archs/multi_res_rrdb.py
index d95a678e..59f35e42 100644
--- a/codes/models/archs/multi_res_rrdb.py
+++ b/codes/models/archs/multi_res_rrdb.py
@@ -2,8 +2,8 @@ import torch.nn as nn
 import torch.nn.functional as F
 
 from models.archs.RRDBNet_arch import RRDB
-from models.archs.arch_util import make_layer, default_init_weights, ConvGnSilu, ConvGnLelu
-from utils.util import checkpoint
+from models.archs.arch_util import make_layer, default_init_weights, ConvGnSilu, ConvGnLelu, PixelUnshuffle
+from utils.util import checkpoint, sequential_checkpoint
 
 
 class MultiLevelRRDB(nn.Module):
@@ -81,3 +81,126 @@ class MultiResRRDBNet(nn.Module):
 
     def visual_dbg(self, step, path):
         pass
+
+
+class SteppedResRRDBNet(nn.Module):
+    def __init__(self,
+                 in_channels,
+                 out_channels,
+                 mid_channels=64,
+                 l1_blocks=3,
+                 l2_blocks=3,
+                 growth_channels=32,
+                 scale=4,
+                 ):
+        super().__init__()
+        self.scale = scale
+        self.in_channels = in_channels
+
+        self.conv_first = nn.Conv2d(in_channels, mid_channels, 7, stride=2, padding=3)
+        self.conv_second = nn.Conv2d(mid_channels, mid_channels*2, 3, stride=2, padding=1)
+
+        self.l1_blocks = nn.Sequential(*[RRDB(mid_channels*2, growth_channels*2) for _ in range(l1_blocks)])
+        self.l1_upsample_conv = nn.Conv2d(mid_channels*2, mid_channels, 3, stride=1, padding=1)
+        self.l2_blocks = nn.Sequential(*[RRDB(mid_channels, growth_channels, 2) for _ in range(l2_blocks)])
+
+        self.conv_body = nn.Conv2d(mid_channels, mid_channels, 3, 1, 1)
+        # upsample
+        self.conv_up1 = nn.Conv2d(mid_channels, mid_channels, 3, 1, 1)
+        self.conv_up2 = nn.Conv2d(mid_channels, mid_channels, 3, 1, 1)
+        self.conv_hr = nn.Conv2d(mid_channels, mid_channels, 3, 1, 1)
+        self.conv_last = nn.Conv2d(mid_channels, out_channels, 3, 1, 1)
+        self.lrelu = nn.LeakyReLU(negative_slope=0.2, inplace=True)
+
+        for m in [
+            self.conv_first, self.conv_second, self.l1_upsample_conv, self.conv_body, self.conv_up1,
+            self.conv_up2, self.conv_hr, self.conv_last
+        ]:
+            if m is not None:
+                default_init_weights(m, 0.1)
+
+    def forward(self, x):
+        trunk = self.conv_first(x)
+        trunk = self.conv_second(trunk)
+        trunk = sequential_checkpoint(self.l1_blocks, len(self.l2_blocks), trunk)
+        trunk = F.interpolate(trunk, scale_factor=2, mode="nearest")
+        trunk = self.l1_upsample_conv(trunk)
+        trunk = sequential_checkpoint(self.l2_blocks, len(self.l2_blocks), trunk)
+        body_feat = self.conv_body(trunk)
+        feat = trunk + body_feat
+
+        # upsample
+        out = self.lrelu(
+            self.conv_up1(F.interpolate(feat, scale_factor=2, mode='nearest')))
+        if self.scale == 4:
+            out = self.lrelu(
+                self.conv_up2(F.interpolate(out, scale_factor=2, mode='nearest')))
+        else:
+            out = self.lrelu(self.conv_up2(out))
+        out = self.conv_last(self.lrelu(self.conv_hr(out)))
+
+        return out
+
+    def visual_dbg(self, step, path):
+        pass
+
+
+class PixelShufflingSteppedResRRDBNet(nn.Module):
+    def __init__(self,
+                 in_channels,
+                 out_channels,
+                 mid_channels=64,
+                 l1_blocks=3,
+                 l2_blocks=3,
+                 growth_channels=32,
+                 scale=2,
+                 ):
+        super().__init__()
+        self.scale = scale * 2  # This RRDB operates at half-scale resolution.
+        self.in_channels = in_channels
+
+        self.pix_unshuffle = PixelUnshuffle(4)
+        self.conv_first = nn.Conv2d(4*4*in_channels, mid_channels*2, 3, stride=1, padding=1)
+
+        self.l1_blocks = nn.Sequential(*[RRDB(mid_channels*2, growth_channels*2) for _ in range(l1_blocks)])
+        self.l1_upsample_conv = nn.Conv2d(mid_channels*2, mid_channels, 3, stride=1, padding=1)
+        self.l2_blocks = nn.Sequential(*[RRDB(mid_channels, growth_channels, 2) for _ in range(l2_blocks)])
+
+        self.conv_body = nn.Conv2d(mid_channels, mid_channels, 3, 1, 1)
+        # upsample
+        self.conv_up1 = nn.Conv2d(mid_channels, mid_channels, 3, 1, 1)
+        self.conv_up2 = nn.Conv2d(mid_channels, mid_channels, 3, 1, 1)
+        self.conv_hr = nn.Conv2d(mid_channels, mid_channels, 3, 1, 1)
+        self.conv_last = nn.Conv2d(mid_channels, out_channels, 3, 1, 1)
+        self.lrelu = nn.LeakyReLU(negative_slope=0.2, inplace=True)
+
+        for m in [
+            self.conv_first, self.l1_upsample_conv, self.conv_body, self.conv_up1,
+            self.conv_up2, self.conv_hr, self.conv_last
+        ]:
+            if m is not None:
+                default_init_weights(m, 0.1)
+
+    def forward(self, x):
+        trunk = self.conv_first(self.pix_unshuffle(x))
+        trunk = sequential_checkpoint(self.l1_blocks, len(self.l1_blocks), trunk)
+        trunk = F.interpolate(trunk, scale_factor=2, mode="nearest")
+        trunk = self.l1_upsample_conv(trunk)
+        trunk = sequential_checkpoint(self.l2_blocks, len(self.l2_blocks), trunk)
+        body_feat = self.conv_body(trunk)
+        feat = trunk + body_feat
+
+        # upsample
+        out = self.lrelu(
+            self.conv_up1(F.interpolate(feat, scale_factor=2, mode='nearest')))
+        if self.scale == 4:
+            out = self.lrelu(
+                self.conv_up2(F.interpolate(out, scale_factor=2, mode='nearest')))
+        else:
+            out = self.lrelu(self.conv_up2(out))
+        out = self.conv_last(self.lrelu(self.conv_hr(out)))
+
+        return out
+
+    def visual_dbg(self, step, path):
+        pass