[dev] fix shared weights in ppyoloe head (#7265)

ppdet/modeling/heads/ppyoloe_head.py

@@ -47,7 +47,8 @@ class ESEAttn(nn.Layer):
 @register
 class PPYOLOEHead(nn.Layer):
     __shared__ = [
-        'num_classes', 'eval_size', 'trt', 'exclude_nms', 'exclude_post_process'
+        'num_classes', 'eval_size', 'trt', 'exclude_nms',
+        'exclude_post_process', 'use_shared_conv'
     ]
     __inject__ = ['static_assigner', 'assigner', 'nms']
 
@@ -72,7 +73,8 @@ class PPYOLOEHead(nn.Layer):
                  },
                  trt=False,
                  exclude_nms=False,
-                 exclude_post_process=False):
+                 exclude_post_process=False,
+                 use_shared_conv=True):
         super(PPYOLOEHead, self).__init__()
         assert len(in_channels) > 0, "len(in_channels) should > 0"
         self.in_channels = in_channels
@@ -94,6 +96,8 @@ class PPYOLOEHead(nn.Layer):
             self.nms.trt = trt
         self.exclude_nms = exclude_nms
         self.exclude_post_process = exclude_post_process
+        self.use_shared_conv = use_shared_conv
+
         # stem
         self.stem_cls = nn.LayerList()
         self.stem_reg = nn.LayerList()
@@ -200,14 +204,22 @@ class PPYOLOEHead(nn.Layer):
             reg_dist = self.pred_reg[i](self.stem_reg[i](feat, avg_feat))
             reg_dist = reg_dist.reshape([-1, 4, self.reg_max + 1, l]).transpose(
                 [0, 2, 3, 1])
-            reg_dist = self.proj_conv(F.softmax(reg_dist, axis=1)).squeeze(1)
+            if self.use_shared_conv:
+                reg_dist = self.proj_conv(F.softmax(
+                    reg_dist, axis=1)).squeeze(1)
+            else:
+                reg_dist = F.softmax(reg_dist, axis=1)
             # cls and reg
             cls_score = F.sigmoid(cls_logit)
             cls_score_list.append(cls_score.reshape([-1, self.num_classes, l]))
             reg_dist_list.append(reg_dist)
 
         cls_score_list = paddle.concat(cls_score_list, axis=-1)
-        reg_dist_list = paddle.concat(reg_dist_list, axis=1)
+        if self.use_shared_conv:
+            reg_dist_list = paddle.concat(reg_dist_list, axis=1)
+        else:
+            reg_dist_list = paddle.concat(reg_dist_list, axis=2)
+            reg_dist_list = self.proj_conv(reg_dist_list).squeeze(1)
 
         return cls_score_list, reg_dist_list, anchor_points, stride_tensor