Wrong file pattern in Write() function of those vtkXXXImageWriters without setting FileName
This issue was created automatically from an original Mantis Issue. Further discussion may take place here.
In vtk's vtkImageWriter/vtkJPEGWriter/vtkPNGWriter/etc, if not setting FileName ,FilePrefix and FilePattern, it would go to the third condition to call:
sprintf( this->InternalFileName, this ->FilePattern,this->FileNumber);
but the default FilePattern is "%s.%d" and it can't work correctly. Checking the FilePattern is needed, I think.