can rev supply image editing features?

[Tiemo Hollmann TB]

Hello,

I am not that familiar with the image manipulating capabilities of rev. I
have a batch of images with a person in front of a blue background.

What I would like to do is to change the blue background against a white
background, so that a printed image has a better contrast. Up to now I
thought that this is a photoshop job, but I am always again surprised what
people do with rev (blending, masking, etc.). Or any externals for Mac and
Win? I don't know if at all it would be possible, to find and select
automatically the "background" (e.g. select always the topleft corner) and
select all of the blue, like photoshops wizard selecting tool with some
tolerance of 10 or 20%, because the RGB isn't that plain over the whole
background.

So I wonder, if there are any ideas on this list, how to do this job

Thanks

Tiemo