Inside out image?

[jimlolo]

Is there any way to reverse this image in the radial direction, so that peaks are valleys and valleys are peaks? Essentially  z = 1 - z

[Trevor.Dennis]

Is this a single layer raster image? I suspect that it is.

[Semaphoric]

I'm not sure if this is what you're after, but I tried converting the image to Lab mode, inverting the Lightness channel, and converting back to RGB:

[Trevor.Dennis]

Woah there John.  We can't compete with alchemy and magic. 😉 

[jimlolo]

Thanks for all the ideas. Need to spend time on them. Essentially I want those concave channels be convexx (rising above the flat sections, not embossed in).

[davescm]

An alternative.

Add a duplicate layer.

Use Filter >Stylise>Emboss

Set that layer to Luminosity Blend mode

Add a curves adjustment layer clipped to that new layer and adjust, along with the opacity of the filtered layer, to get the desired effect.

Dave

[Trevor.Dennis]

It's like one of those optical illusions Dave.  You stare at the image, and randomly changes between peeks and trough depending on how your brain perceives the light direction.  A nice approach to a tricky problem though.

[Semaphoric]

My first idea was just turn it over, like the Cake Slice Illusion (one slice gone, or one slice left?):

 https://lapercepcion16.blogspot.com/2016/03/ilusiones-opticas.html 

[davescm]

It is a bit strange and the optical effect does come and go. In reality, a better way is model it from scratch in a 3D app, it is just a rounded cylinder. The surface detail can be added to that cylinder, then light it accordingly and render it.  Reversing the surface would simply be changing the height or normal map.

Dave