I'm dealing with presentation state objects and the grayscale pipeline
and I have a few questions about how to apply correctly the
photometric interpretation when this is of type MONOCHROME1.

I've read several messages about this feature on this group but I want
to be sure that what I'm doing is right.

In the case I have a single image, with no presentation state
attached, when is supposed I have to reverse the values in the
pipeline? If i have a VOI lut, do I have to reverse the resulting
values? If I have the VOI transform defined by a window level
operation, do I have to turn the sign of the window width/level

When I have an attached presentation state to the image, it is
supposed the photometric interpretation does not make sense and I can
ignore it?

As a side note, can be a presentation lut be present in a dicom image
or it only can be present in a presentation state?