Does anyone know if either the iTunes or Vudu digital HD versions are from the Criteron Bluray versions, or just upscaled “HD” from MGM? I’m suspect of the qua

Does anyone know if either the iTunes or Vudu digital HD versions are from the Criteron Bluray versions, or just upscaled “HD” from MGM? I’m suspect of the quality that I might get if I buy the digital versions vs just shelling out for the Qatsi Bluray Criterion trilogy (I know that physical is always leaps and bounds better than streaming digital but that is not what this question is about).