pytorch DCNv2使用方式

主要注意offset的获得方式：

from torchvision.ops import DeformConv2d

class DConv(nn.Module):
    def __init__(self, inplanes, planes, kernel_size=3, stride=1, padding=1, bias=False):
        super(DConv, self).__init__()
        self.conv1 = nn.Conv2d(inplanes, 2 * kernel_size * kernel_size, kernel_size=kernel_size,
                               stride=stride, padding=padding, bias=bias)
        self.conv2 = DeformConv2d(inplanes, planes, kernel_size=kernel_size, stride=stride, padding=padding, bias=bias)

    def forward(self, x):
        out = self.conv1(x)
        out = self.conv2(x, out)
        return out