从预训练的 Conv2D 初始化Conv3D 的代码实现

# w = vae_2d_ckpt["state_dict"][key_2d]            
conv2d = nn.Conv2d(in_channels=128, out_channels=256, kernel_size=3, stride=1, padding=0)
conv3d = nn.Conv3d(in_channels=128, out_channels=256, kernel_size=3, stride=1, padding=0)
#conv2d weight 
w_2d = conv2d.weight.data
w_3d = conv3d.weight.data
print(w_2d.shape)
print(w_3d.shape)

#  kernel_matrix = (num_kernels, num_filters_perkernel, (Time,) Height, Width)
w_3d = torch.zeros(w_3d.shape, dtype=w_2d.dtype)
w_3d = w_2d.unsqueeze(2).expand_as(w_3d)  # average initialization
w_3d[:,:,-1,:,:] = w_2d  # tail initialization
w_3d[:, :, w_3d.shape[2]//2, :, :] = w_2d  # center initialization

print(w_3d.shape)
conv3d.weight.data = w_3d