change yolo.py

This commit is contained in:
Zhang Wei committed 2026-03-14 12:38:08 +08:00
1 parent 9b008eaa99
commit b586eee607
1 file changed
+99 -10
+99 -10
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@@ -68,6 +68,30 @@ try:
except ImportError:
thop = None
# 新增
class ECAAttention(nn.Module):
"""Efficient Channel Attention for lightweight channel re-weighting."""
def __init__(self, k_size=3):
super().__init__()
self.avg_pool = nn.AdaptiveAvgPool2d(1)
self.conv = nn.Conv1d(
in_channels=1,
out_channels=1,
kernel_size=k_size,
padding=(k_size - 1) // 2,
bias=False,
)
self.sigmoid = nn.Sigmoid()
def forward(self, x):
# x: [B, C, H, W]
y = self.avg_pool(x) # [B, C, 1, 1]
y = y.squeeze(-1).transpose(-1, -2) # [B, 1, C]
y = self.conv(y) # [B, 1, C]
y = y.transpose(-1, -2).unsqueeze(-1) # [B, C, 1, 1]
y = self.sigmoid(y)
return x * y.expand_as(x)
class Detect(nn.Module):
"""YOLOv5 Detect head for processing input tensors and generating detection outputs in object detection models."""
@@ -126,6 +150,60 @@ class Detect(nn.Module):
anchor_grid = (self.anchors[i] * self.stride[i]).view((1, self.na, 1, 1, 2)).expand(shape)
return grid, anchor_grid
# 新增
class ECADetect(nn.Module):
"""YOLOv5 Detect head with ECA attention before prediction conv."""
stride = None
dynamic = False
export = False
def __init__(self, nc=80, anchors=(), ch=(), inplace=True, eca_k=3):
super().__init__()
self.nc = nc # number of classes
self.no = nc + 5 # number of outputs per anchor
self.nl = len(anchors) # number of detection layers
self.na = len(anchors[0]) // 2 # number of anchors
self.grid = [torch.empty(0) for _ in range(self.nl)] # init grid
self.anchor_grid = [torch.empty(0) for _ in range(self.nl)] # init anchor grid
self.register_buffer("anchors", torch.tensor(anchors).float().view(self.nl, -1, 2))
self.inplace = inplace
# one ECA module for each detection scale
self.eca = nn.ModuleList(ECAAttention(k_size=eca_k) for _ in ch)
# same prediction conv as original YOLOv5 Detect
self.m = nn.ModuleList(nn.Conv2d(x, self.no * self.na, 1) for x in ch)
def forward(self, x):
z = [] # inference output
for i in range(self.nl):
x[i] = self.eca[i](x[i]) # ECA enhancement
x[i] = self.m[i](x[i]) # prediction conv
bs, _, ny, nx = x[i].shape
x[i] = x[i].view(bs, self.na, self.no, ny, nx).permute(0, 1, 3, 4, 2).contiguous()
if not self.training:
if self.dynamic or self.grid[i].shape[2:4] != x[i].shape[2:4]:
self.grid[i], self.anchor_grid[i] = self._make_grid(nx, ny, i)
xy, wh, conf = x[i].sigmoid().split((2, 2, self.nc + 1), 4)
xy = (xy * 2 + self.grid[i]) * self.stride[i]
wh = (wh * 2) ** 2 * self.anchor_grid[i]
y = torch.cat((xy, wh, conf), 4)
z.append(y.view(bs, self.na * nx * ny, self.no))
return x if self.training else (torch.cat(z, 1),) if self.export else (torch.cat(z, 1), x)
def _make_grid(self, nx=20, ny=20, i=0, torch_1_10=check_version(torch.__version__, "1.10.0")):
d = self.anchors[i].device
t = self.anchors[i].dtype
shape = 1, self.na, ny, nx, 2
y, x = torch.arange(ny, device=d, dtype=t), torch.arange(nx, device=d, dtype=t)
yv, xv = torch.meshgrid(y, x, indexing="ij") if torch_1_10 else torch.meshgrid(y, x)
grid = torch.stack((xv, yv), 2).expand(shape) - 0.5
anchor_grid = (self.anchors[i] * self.stride[i]).view((1, self.na, 1, 1, 2)).expand(shape)
return grid, anchor_grid
class Segment(Detect):
"""YOLOv5 Segment head for segmentation models, extending Detect with mask and prototype layers."""
@@ -207,7 +285,8 @@ class BaseModel(nn.Module):
"""
self = super()._apply(fn)
m = self.model[-1] # Detect()
if isinstance(m, (Detect, Segment)):
# if isinstance(m, (Detect, Segment)):
if isinstance(m, (Detect, ECADetect, Segment)):
m.stride = fn(m.stride)
m.grid = list(map(fn, m.grid))
if isinstance(m.anchor_grid, list):
@@ -244,7 +323,8 @@ class DetectionModel(BaseModel):
# Build strides, anchors
m = self.model[-1] # Detect()
if isinstance(m, (Detect, Segment)):
# if isinstance(m, (Detect, Segment)):
if isinstance(m, (Detect, ECADetect, Segment)):
def _forward(x):
"""Passes the input 'x' through the model and returns the processed output."""
@@ -322,13 +402,21 @@ class DetectionModel(BaseModel):
"""
# cf = torch.bincount(torch.tensor(np.concatenate(dataset.labels, 0)[:, 0]).long(), minlength=nc) + 1.
m = self.model[-1] # Detect() module
for mi, s in zip(m.m, m.stride): # from
b = mi.bias.view(m.na, -1) # conv.bias(255) to (3,85)
b.data[:, 4] += math.log(8 / (640 / s) ** 2) # obj (8 objects per 640 image)
b.data[:, 5 : 5 + m.nc] += (
math.log(0.6 / (m.nc - 0.99999)) if cf is None else torch.log(cf / cf.sum())
) # cls
mi.bias = torch.nn.Parameter(b.view(-1), requires_grad=True)
# for mi, s in zip(m.m, m.stride): # from
# b = mi.bias.view(m.na, -1) # conv.bias(255) to (3,85)
# b.data[:, 4] += math.log(8 / (640 / s) ** 2) # obj (8 objects per 640 image)
# b.data[:, 5 : 5 + m.nc] += (
# math.log(0.6 / (m.nc - 0.99999)) if cf is None else torch.log(cf / cf.sum())
# ) # cls
# mi.bias = torch.nn.Parameter(b.view(-1), requires_grad=True)
if isinstance(m, (Detect, ECADetect)):
for mi, s in zip(m.m, m.stride):
b = mi.bias.view(m.na, -1)
b.data[:, 4] += math.log(8 / (640 / s) ** 2)
b.data[:, 5:5 + m.nc] += (
math.log(0.6 / (m.nc - 0.99999)) if cf is None else torch.log(cf / cf.sum())
)
mi.bias = torch.nn.Parameter(b.view(-1), requires_grad=True)
Model = DetectionModel # retain YOLOv5 'Model' class for backwards compatibility
@@ -434,7 +522,8 @@ def parse_model(d, ch):
elif m is Concat:
c2 = sum(ch[x] for x in f)
# TODO: channel, gw, gd
elif m in {Detect, Segment}:
# elif m in {Detect, Segment}:
elif m in {Detect, ECADetect, Segment}:
args.append([ch[x] for x in f])
if isinstance(args[1], int): # number of anchors
args[1] = [list(range(args[1] * 2))] * len(f)