Error messages

[WARNING] [VideoGrabber(input)] BaseData_getAttr_value unsupported native type=cvMat for data fullFrame ; returning string value
[ERROR]   [PythonScript] 'str' object has no attribute 'getPtr'
Python Stack:
  File "test.py", line 55, in createScene
    TemplateMatcher(rootNode,argv)
  File "test.py", line 19, in __init__
    self.createGraph(node)
  File "test.py", line 32, in createGraph
    image = SofaOR.mat_as_numpy(self.input.fullFrame)
  File "/home/bruno/dev/SofaOR/SofaORCommon/python/SofaOR/__init__.py", line 9, in mat_as_numpy
    ptrs, shape, typename = img.getPtr()