Setting graphical window as per image size

Hi everyone,

I am struggling to fit the graphical window size acording to the image size otherwise it takes a lot space. Could you please suggest how to do this?

Please clarify your question.

Thanks @mwestphal I managed to do that. Actually, I wanted the image to fit in the display window size. Could you please take a look at this QCriterion in Paraview

Actually, I have been trying to create Q-criterion following the procedure already posted. I have exported three components of velocity vector as a case file to the Paraview but after using Gradient of Unstructured Dataset filter I get an error.

ERROR: In C:\bbd\8fbebceb\build\superbuild\paraview\src\VTK\Filters\General\vtkGradientFilter.cxx, line 305
vtkGradientFilter (000002358DD037E0): No input array. If this dataset is part of a composite dataset check to make sure that all non-empty blocks have this array.

ERROR: In C:\bbd\8fbebceb\build\superbuild\paraview\src\VTK\Common\ExecutionModel\vtkExecutive.cxx, line 753
vtkPVCompositeDataPipeline (0000023596CE4580): Algorithm vtkGradientFilter(000002358DD037E0) returned failure for request: vtkInformation (00000235932A38C0)
Debug: Off
Modified Time: 2845835
Reference Count: 1
Registered Events: (none)