File size: 6,207 Bytes
6a52406
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
b9015b6
6a52406
b9015b6
6a52406
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
645ab7f
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
import gradio as gr
import torch
import torch.nn as nn
import torch.nn.functional as F
import matplotlib.pyplot as plt

class DoubleConv(nn.Module):
    def __init__(self, in_channels, out_channels, mid_channels=None, residual=False):
        super().__init__()
        self.residual = residual
        if not mid_channels:
            mid_channels = out_channels
        self.double_conv = nn.Sequential(
            nn.Conv2d(in_channels, mid_channels, kernel_size=3, padding=1, bias=False),
            nn.GroupNorm(1, mid_channels),
            nn.GELU(),
            nn.Conv2d(mid_channels, out_channels, kernel_size=3, padding=1, bias=False),
            nn.GroupNorm(1, out_channels),
        )

    def forward(self, x):
        if self.residual:
            return F.gelu(x + self.double_conv(x))
        else:
            return self.double_conv(x)

class Down(nn.Module):
    def __init__(self, in_channels, out_channels, emb_dim=256):
        super().__init__()
        self.maxpool_conv = nn.Sequential(
            nn.MaxPool2d(2),
            DoubleConv(in_channels, in_channels, residual=True),
            DoubleConv(in_channels, out_channels),
        )

        self.emb_layer = nn.Sequential(
            nn.SiLU(),
            nn.Linear(
                emb_dim,
                out_channels
            ),
        )

    def forward(self, x, t):
        x = self.maxpool_conv(x)
        emb = self.emb_layer(t)[:, :, None, None].repeat(1, 1, x.shape[-2], x.shape[-1])
        return x + emb

class Up(nn.Module):
    def __init__(self, in_channels, out_channels, emb_dim=256):
        super().__init__()

        self.up = nn.Upsample(scale_factor=2, mode="bilinear", align_corners=True)
        self.conv = nn.Sequential(
            DoubleConv(in_channels, in_channels, residual=True),
            DoubleConv(in_channels, out_channels, in_channels // 2),
        )

        self.emb_layer = nn.Sequential(
            nn.SiLU(),
            nn.Linear(
                emb_dim,
                out_channels
            ),
        )

    def forward(self, x, skip_x, t):
        x = self.up(x)
        x = torch.cat([skip_x, x], dim=1)
        x = self.conv(x)
        emb = self.emb_layer(t)[:, :, None, None].repeat(1, 1, x.shape[-2], x.shape[-1])
        return x + emb

class UNet(nn.Module):
    def __init__(self, c_in=3, c_out=3, time_dim=256, device="cuda"):
        super().__init__()
        self.device = device
        self.time_dim = time_dim

        self.inc = DoubleConv(c_in, 64)
        self.down1 = Down(64, 128)
        self.down2 = Down(128, 256)
        self.down3 = Down(256, 256)

        self.bot1 = DoubleConv(256, 512)
        self.bot2 = DoubleConv(512, 512)
        self.bot3 = DoubleConv(512, 256)

        self.up1 = Up(512, 128)
        self.up2 = Up(256, 64)
        self.up3 = Up(128, 64)
        self.outc = nn.Conv2d(64, c_out, kernel_size=1)

    def positional_encoding(self, t, channels):
        inv_freq = 1.0 / (
            10000
            ** (torch.arange(0, channels, 2, device=self.device).float() / channels)
        )
        pos_enc_a = torch.sin(t.repeat(1, channels // 2) * inv_freq)
        pos_enc_b = torch.cos(t.repeat(1, channels // 2) * inv_freq)
        pos_enc = torch.cat([pos_enc_a, pos_enc_b], dim=-1)
        return pos_enc

    def forward(self, image, t):
        t = t.unsqueeze(-1).type(torch.float)
        t = self.positional_encoding(t, self.time_dim)

        x1 = self.inc(image)
        x2 = self.down1(x1, t)
        x3 = self.down2(x2, t)
        x4 = self.down3(x3, t)

        x4 = self.bot1(x4)
        # x4 = self.bot2(x4)
        x4 = self.bot3(x4)

        x = self.up1(x4, x3, t)
        x = self.up2(x, x2, t)
        x = self.up3(x, x1, t)
        output = self.outc(x)
        return output
device = 'cuda' if torch.cuda.is_available() else 'cpu'
model = UNet(device = device).to(device)
model.load_state_dict(torch.load('Model_Saved_States/diffusion_64.pth', map_location=torch.device(device)))
img_size = 64
class Diffusion():
  def __init__(self, time_steps = 500, beta_start = 0.0001, beta_stop = 0.02, image_size = 64, device = device):
    self.time_steps = time_steps
    self.beta_start = beta_start
    self.beta_stop = beta_stop
    self.img_size = image_size
    self.device = device

    self.beta = self.beta_schedule()
    self.beta = self.beta.to(device)
    self.alpha = 1 - self.beta
    self.alpha = self.alpha.to(device)
    self.alpha_hat = torch.cumprod(self.alpha, dim = 0).to(device)


  def beta_schedule(self):
    return torch.linspace(self.beta_start, self.beta_stop, self.time_steps)

  def noise_images(self, images, t):
    sqrt_alpha_hat = torch.sqrt(self.alpha_hat[t])[:, None, None, None,]
    sqrt_one_minus_alpha_hat = torch.sqrt(1 - self.alpha_hat[t])[:, None, None, None,]
    noises = torch.randn_like(images)
    noised_images = sqrt_alpha_hat * images + sqrt_one_minus_alpha_hat * noises
    return noised_images, noises

  def random_timesteps(self, n):
    return torch.randint(low=1, high=self.time_steps, size=(n,))

  def generate_samples(self, model, n):
    with torch.no_grad():
            x = torch.randn((n, 3, self.img_size, self.img_size)).to(self.device)
            for i in range(self.time_steps - 1, 1, -1):
                t = (torch.ones(n) * i).long().to(self.device)
                predicted_noise = model(x, t)
                alpha = self.alpha[t][:, None, None, None]
                alpha_hat = self.alpha_hat[t][:, None, None, None]
                beta = self.beta[t][:, None, None, None]
                if i > 1:
                    noise = torch.randn_like(x)
                else:
                    noise = torch.zeros_like(x)
                x = 1 / torch.sqrt(alpha) * (x - ((1 - alpha) / (torch.sqrt(1 - alpha_hat))) * predicted_noise) + torch.sqrt(beta) * noise

    return (x[0].cpu().numpy().transpose(1, 2, 0) / 255)
      #show_images

diffusion = Diffusion()

import numpy as np
def greet(n):
    image = diffusion.generate_samples(model, n = 1)
    image = (np.clip(image * 255, -1, 1) + 1) / 2
    plt.imshow(image)
    return image

iface = gr.Interface(fn=greet, inputs="number", outputs="image")
iface.launch()