This image is from a year or so ago, when the photo club had an assignment coming up of "Abstraction". I remember a shot by Craig Tanner of a similar plant and while I was at our lakehouse near Burnet I saw these century plants and tried my version. When processing it I thought maybe it was too recognizable as a plant to be an abstract and tried some treatments to emphasize the radiating lines of the leaves. The lower image is the result of a black and white adjustment layer with the blending mode changed to "difference" --- yes, changing from "normal" to "difference" turned it blue. I have since tried to start from the original raw file and recreate this look, but have not been able to. It has been over a year since I first processed it and I can no longer remember what I did.
Camera info: Nikon D200, 60 mm macro lens at f3.2 and 1/500th with a -.33 exposure compensation, ISO 100, sunny whitebalance
Post processing: lower image: duplicated the background in multiply at 12% opacity, Levels for global brightening, black and white adjustment layer in Difference blending mode, another Levels for brightening, sharpened with the Edge