pytorch nn.Conv2d()中的padding以及输出大小方式

conv1=nn.Conv2d(1,2,kernel_size=3,padding=1)
conv2=nn.Conv2d(1,2,kernel_size=3)
 
inputs=torch.Tensor([[[[1,2,3],
           [4,5,6],
           [7,8,9]]]])
print("input size: ",inputs.shape)
outputs1=conv1(inputs)
print("output1 size: ",outputs1.shape)
outputs2=conv2(inputs)
print("output2 size: ",outputs2.shape)
 
输出：
input size: torch.Size([1, 1, 3, 3])
output1 size: torch.Size([1, 2, 3, 3])
output2 size: torch.Size([1, 2, 1, 1])