First commit OCR_earsing and Synthetics Handwritten Recognition awesome repo

OCR_earsing/latent_diffusion/taming/modules/util.py

@@ -0,0 +1,130 @@
+import torch
+import torch.nn as nn
+
+
+def count_params(model):
+    total_params = sum(p.numel() for p in model.parameters())
+    return total_params
+
+
+class ActNorm(nn.Module):
+    def __init__(self, num_features, logdet=False, affine=True,
+                 allow_reverse_init=False):
+        assert affine
+        super().__init__()
+        self.logdet = logdet
+        self.loc = nn.Parameter(torch.zeros(1, num_features, 1, 1))
+        self.scale = nn.Parameter(torch.ones(1, num_features, 1, 1))
+        self.allow_reverse_init = allow_reverse_init
+
+        self.register_buffer('initialized', torch.tensor(0, dtype=torch.uint8))
+
+    def initialize(self, input):
+        with torch.no_grad():
+            flatten = input.permute(1, 0, 2, 3).contiguous().view(input.shape[1], -1)
+            mean = (
+                flatten.mean(1)
+                .unsqueeze(1)
+                .unsqueeze(2)
+                .unsqueeze(3)
+                .permute(1, 0, 2, 3)
+            )
+            std = (
+                flatten.std(1)
+                .unsqueeze(1)
+                .unsqueeze(2)
+                .unsqueeze(3)
+                .permute(1, 0, 2, 3)
+            )
+
+            self.loc.data.copy_(-mean)
+            self.scale.data.copy_(1 / (std + 1e-6))
+
+    def forward(self, input, reverse=False):
+        if reverse:
+            return self.reverse(input)
+        if len(input.shape) == 2:
+            input = input[:,:,None,None]
+            squeeze = True
+        else:
+            squeeze = False
+
+        _, _, height, width = input.shape
+
+        if self.training and self.initialized.item() == 0:
+            self.initialize(input)
+            self.initialized.fill_(1)
+
+        h = self.scale * (input + self.loc)
+
+        if squeeze:
+            h = h.squeeze(-1).squeeze(-1)
+
+        if self.logdet:
+            log_abs = torch.log(torch.abs(self.scale))
+            logdet = height*width*torch.sum(log_abs)
+            logdet = logdet * torch.ones(input.shape[0]).to(input)
+            return h, logdet
+
+        return h
+
+    def reverse(self, output):
+        if self.training and self.initialized.item() == 0:
+            if not self.allow_reverse_init:
+                raise RuntimeError(
+                    "Initializing ActNorm in reverse direction is "
+                    "disabled by default. Use allow_reverse_init=True to enable."
+                )
+            else:
+                self.initialize(output)
+                self.initialized.fill_(1)
+
+        if len(output.shape) == 2:
+            output = output[:,:,None,None]
+            squeeze = True
+        else:
+            squeeze = False
+
+        h = output / self.scale - self.loc
+
+        if squeeze:
+            h = h.squeeze(-1).squeeze(-1)
+        return h
+
+
+class AbstractEncoder(nn.Module):
+    def __init__(self):
+        super().__init__()
+
+    def encode(self, *args, **kwargs):
+        raise NotImplementedError
+
+
+class Labelator(AbstractEncoder):
+    """Net2Net Interface for Class-Conditional Model"""
+    def __init__(self, n_classes, quantize_interface=True):
+        super().__init__()
+        self.n_classes = n_classes
+        self.quantize_interface = quantize_interface
+
+    def encode(self, c):
+        c = c[:,None]
+        if self.quantize_interface:
+            return c, None, [None, None, c.long()]
+        return c
+
+
+class SOSProvider(AbstractEncoder):
+    # for unconditional training
+    def __init__(self, sos_token, quantize_interface=True):
+        super().__init__()
+        self.sos_token = sos_token
+        self.quantize_interface = quantize_interface
+
+    def encode(self, x):
+        # get batch size from data and replicate sos_token
+        c = torch.ones(x.shape[0], 1)*self.sos_token
+        c = c.long().to(x.device)
+        if self.quantize_interface:
+            return c, None, [None, None, c]
+        return c