def __init__(self,
in_channels,
out_channels=None,
norm=True,
activation=False,
onnx_export=False):
super(SeparableConvBlock, self).__init__()
if out_channels is None:
out_channels = in_channels
self.depthwise_conv = Conv2dStaticSamePadding(in_channels,
in_channels,
kernel_size=3,
stride=1,
groups=in_channels,
bias=False)
self.pointwise_conv = Conv2dStaticSamePadding(in_channels,
out_channels,
kernel_size=1,
stride=1)
self.norm = norm
if self.norm:
self.bn = nn.BatchNorm2d(num_features=out_channels,
momentum=0.01,
eps=1e-3)
self.activation = activation
if self.activation:
self.swish = MemoryEfficientSwish() if not onnx_export else Swish()
def __init__(self, num_channels, conv_channels, first_time=False, epsilon=1e-4, onnx_export=False, attention=True):
super(BiFPN, self).__init__()
self.epsilon = epsilon
self.conv6_up = SeparableConvBlock(num_channels, onnx_export=onnx_export)
self.conv5_up = SeparableConvBlock(num_channels, onnx_export=onnx_export)
self.conv4_up = SeparableConvBlock(num_channels, onnx_export=onnx_export)
self.conv3_up = SeparableConvBlock(num_channels, onnx_export=onnx_export)
self.conv4_down = SeparableConvBlock(num_channels, onnx_export=onnx_export)
self.conv5_down = SeparableConvBlock(num_channels, onnx_export=onnx_export)
self.conv6_down = SeparableConvBlock(num_channels, onnx_export=onnx_export)
self.conv7_down = SeparableConvBlock(num_channels, onnx_export=onnx_export)
self.p6_upsample = nn.Upsample(scale_factor=2, mode='nearest')
self.p5_upsample = nn.Upsample(scale_factor=2, mode='nearest')
self.p4_upsample = nn.Upsample(scale_factor=2, mode='nearest')
self.p3_upsample = nn.Upsample(scale_factor=2, mode='nearest')
self.p4_downsample = MaxPool2dStaticSamePadding(3, 2)
self.p5_downsample = MaxPool2dStaticSamePadding(3, 2)
self.p6_downsample = MaxPool2dStaticSamePadding(3, 2)
self.p7_downsample = MaxPool2dStaticSamePadding(3, 2)
self.swish = MemoryEfficientSwish() if not onnx_export else Swish()
self.first_time = first_time
if self.first_time:
# 获取到了efficientnet的最后三层，对其进行通道的下压缩
self.p5_down_channel = nn.Sequential(
Conv2dStaticSamePadding(conv_channels[2], num_channels, 1),
nn.BatchNorm2d(num_channels, momentum=0.01, eps=1e-3),
)
self.p4_down_channel = nn.Sequential(
Conv2dStaticSamePadding(conv_channels[1], num_channels, 1),
nn.BatchNorm2d(num_channels, momentum=0.01, eps=1e-3),
)
self.p3_down_channel = nn.Sequential(
Conv2dStaticSamePadding(conv_channels[0], num_channels, 1),
nn.BatchNorm2d(num_channels, momentum=0.01, eps=1e-3),
)
# 对输入进来的p5进行宽高的下采样
self.p5_to_p6 = nn.Sequential(
Conv2dStaticSamePadding(conv_channels[2], num_channels, 1),
nn.BatchNorm2d(num_channels, momentum=0.01, eps=1e-3),
MaxPool2dStaticSamePadding(3, 2)
)
self.p6_to_p7 = nn.Sequential(
MaxPool2dStaticSamePadding(3, 2)
)
# BIFPN第一轮的时候，跳线那里并不是同一个in
self.p4_down_channel_2 = nn.Sequential(
Conv2dStaticSamePadding(conv_channels[1], num_channels, 1),
nn.BatchNorm2d(num_channels, momentum=0.01, eps=1e-3),
)
self.p5_down_channel_2 = nn.Sequential(
Conv2dStaticSamePadding(conv_channels[2], num_channels, 1),
nn.BatchNorm2d(num_channels, momentum=0.01, eps=1e-3),
)
# 简易注意力机制的weights
self.p6_w1 = nn.Parameter(torch.ones(2, dtype=torch.float32), requires_grad=True)
self.p6_w1_relu = nn.ReLU()
self.p5_w1 = nn.Parameter(torch.ones(2, dtype=torch.float32), requires_grad=True)
self.p5_w1_relu = nn.ReLU()
self.p4_w1 = nn.Parameter(torch.ones(2, dtype=torch.float32), requires_grad=True)
self.p4_w1_relu = nn.ReLU()
self.p3_w1 = nn.Parameter(torch.ones(2, dtype=torch.float32), requires_grad=True)
self.p3_w1_relu = nn.ReLU()
self.p4_w2 = nn.Parameter(torch.ones(3, dtype=torch.float32), requires_grad=True)
self.p4_w2_relu = nn.ReLU()
self.p5_w2 = nn.Parameter(torch.ones(3, dtype=torch.float32), requires_grad=True)
self.p5_w2_relu = nn.ReLU()
self.p6_w2 = nn.Parameter(torch.ones(3, dtype=torch.float32), requires_grad=True)
self.p6_w2_relu = nn.ReLU()
self.p7_w2 = nn.Parameter(torch.ones(2, dtype=torch.float32), requires_grad=True)
self.p7_w2_relu = nn.ReLU()
self.attention = attention