add rerender lora

animation/rerender-lora/src/img_util.py

@@ -0,0 +1,23 @@
+import einops
+import torch
+import torch.nn.functional as F
+
+
+@torch.no_grad()
+def find_flat_region(mask):
+    device = mask.device
+    kernel_x = torch.Tensor([[-1, 0, 1], [-1, 0, 1],
+                             [-1, 0, 1]]).unsqueeze(0).unsqueeze(0).to(device)
+    kernel_y = torch.Tensor([[-1, -1, -1], [0, 0, 0],
+                             [1, 1, 1]]).unsqueeze(0).unsqueeze(0).to(device)
+    mask_ = F.pad(mask.unsqueeze(0), (1, 1, 1, 1), mode='replicate')
+
+    grad_x = torch.nn.functional.conv2d(mask_, kernel_x)
+    grad_y = torch.nn.functional.conv2d(mask_, kernel_y)
+    return ((abs(grad_x) + abs(grad_y)) == 0).float()[0]
+
+
+def numpy2tensor(img):
+    x0 = torch.from_numpy(img.copy()).float().cuda() / 255.0 * 2.0 - 1.
+    x0 = torch.stack([x0], dim=0)
+    return einops.rearrange(x0, 'b h w c -> b c h w').clone()