Mobile SAM部署Android时Torch JIT Trace报错的解决咨询

架构老林

2026-7-3

问题描述

我尝试将GitHub项目中的mobile_sam.ipynb部署到Android，参考视频教程时，在模型准备阶段使用torch.jit.trace追踪模型遇到报错。

使用的追踪代码：

input_tensor = torch.randn(1, 3, 224, 224)  # Adjust the shape according to your model's input requirements

traced_model = torch.jit.trace(mobile_sam, input_tensor)

报错信息：

TypeError                                 Traceback (most recent call last)
Cell In[20], line 2
      1 input_tensor = torch.randn(1, 3, 224, 224)
----> 2 traced_model = torch.jit.trace(mobile_sam, input_tensor)
      3 traced_model.save('mobile_sam_script.pt')
File ~/myenv/lib/python3.11/site-packages/torch/jit/_trace.py:794, in trace(func, example_inputs, optimize, check_trace, check_inputs, check_tolerance, strict, _force_outplace, _module_class,
_compilation_unit, example_kwarg_inputs, _store_inputs)
    792         else:
    793             raise RuntimeError("example_kwarg_inputs should be a dict")
--> 794     return trace_module(
    795         func,
    796         {"forward": example_inputs},
    797         None,
    798         check_trace,
    799         wrap_check_inputs(check_inputs),
    800         check_tolerance,
    801         strict,
    802         _force_outplace,
    803         _module_class,
    804         example_inputs_is_kwarg=isinstance(example_kwarg_inputs, dict),
    805         _store_inputs=_store_inputs
    806     )
    807 if (
    808     hasattr(func, "__self__")
    809     and isinstance(func.__self__, torch.nn.Module)
    810     and func.__name__ == "forward"
    811 ):
    812     if example_inputs is None:
File ~/myenv/lib/python3.11/site-packages/torch/jit/_trace.py:1056, in trace_module(mod, inputs, optimize, check_trace, check_inputs, check_tolerance, strict, _force_outplace, _module_class,
_compilation_unit, example_inputs_is_kwarg, _store_inputs)
   1054 else:
   1055     example_inputs = make_tuple(example_inputs)
--> 1056     module._c._create_method_from_trace( 
   1057         method_name, 
   1058         func, 
   1059         example_inputs, 
   1060         var_lookup_fn, 
   1061         strict, 
   1062        
_force_outplace, 
   1063         argument_names, 
   1064         _store_inputs 
   1065     ) 
   1067 check_trace_method = module._c._get_method(method_name) 
   1069 # Check the trace against new traces created from user-specified inputs
File ~/myenv/lib/python3.11/site-packages/torch/nn/modules/module.py:1501, in Module._call_impl(self, *args, **kwargs) 
   1496 # If we don't have any hooks, we want to skip the rest of the logic in 
   1497 # this function, and just call forward. 
   1498 if not (self._backward_hooks or self._backward_pre_hooks or self._forward_hooks or self._forward_pre_hooks 
   1499         or _global_backward_pre_hooks or _global_backward_hooks 
   1500         or _global_forward_hooks or
_global_forward_pre_hooks):
--> 1501     return forward_call(*args, **kwargs) 
   1502 # Do not call functions when jit is used 
   1503 full_backward_hooks, non_full_backward_hooks = [], []
File ~/myenv/lib/python3.11/site-packages/torch/nn/modules/module.py:1488, in Module._slow_forward(self, *input, **kwargs) 
   1486         recording_scopes = False 
   1487 try:
--> 1488     result = self.forward(*input, **kwargs) 
   1489 finally: 
   1490     if recording_scopes:
File ~/myenv/lib/python3.11/site-packages/torch/utils/_contextlib.py:115, in context_decorator.<locals>.decorate_context(*args, **kwargs)
    112 @functools.wraps(func)
    113 def decorate_context(*args, **kwargs):
    114     with ctx_factory():
--> 115         return func(*args, **kwargs)
TypeError: Sam.forward() missing 1 required positional argument: 'multimask_output'

解决方案

错误核心：Sam.forward() 需要两个输入参数，你只传入了图像张量，缺少 multimask_output 参数。
修改追踪代码，补充第二个参数（False 对应输出单掩码，True 对应多掩码）：

input_tensor = torch.randn(1, 3, 224, 224)
# 按需求传入multimask_output参数
traced_model = torch.jit.trace(mobile_sam, (input_tensor, False))
traced_model.save('mobile_sam_script.pt')

先测试模型调用：直接执行 mobile_sam(input_tensor, False)，确认能正常输出后再做追踪，避免后续问题。
如果后续需要支持交互提示（比如点选、框选），建议用 torch.jit.script 替代 trace，它对动态逻辑的兼容性更好；或者封装模型，固定输入路径适配Android部署需求。

内容的提问来源于stack exchange，提问作者L. Guilherme P. Melquiades