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dmstraker

Sharpening with blurred, inverted Vivid Light

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Another experimental variant on sharpening (just playing about on a Sunday morning):

  1. Duplicate layer twice (so there are three layers).
  2. Top layer: Invert. Blend Mode: Vivid Light. Add Gaussian Blur (radius about 4). The effect looks a bit like a high-pass effect, so...
  3. Middle layer: Blend Mode: Hard Light (or Overlay or Soft Light, if you like)..

There's an odd effect where colour patches appear in light areas. Increasing Gaussian blur can fix this but reduces sharpening effect. You can also add a mask to the top layer and paint them away. I suspect it's caused by the Vivid Light blend algorithm.


Dave Straker

Cameras: Sony A7R2, RX100V

Computers: Win10: Chillblast Photo with i7-3770 + 16Gb RAM + Philips 40in 4K; Surface Pro 4 i5

Favourite word: Aha. For me and for others.

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2 hours ago, MBd said:

actually a cool effect, how did you discover that?

-MBd

Captain Straker keeps coming up with all these interesting left field techniques because he not only thinks outside the box, he actually climbs out of the box himself and runs off over the hills and far away.

I think the word for him is curious. (In a good way, of course!)

 

5 hours ago, dmstraker said:

There's an odd effect where colour patches appear in light areas.

-Dave

I got something similar when I was playing with your Blurred High Pass Sharpen suggestion this morning and trying out different blend modes.

But without your intellectual rigour, I just carried on scrolling til I found something less surprising instead...

(There's a word for that too, but it's not particularly complimentary.)

 

-Thank you for sharing the results of your inquisitive nature with us. It is much appreciated.- :13_upside_down:


Affinity Designer & Photo  :  Win 10

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5 hours ago, MBd said:

actually a cool effect, how did you discover that?

Just going through the various modes for next update to my Blend Mode notes and trying stuff.

Blending inverted duplicates appears in various places so I had a go with the Vivid Light. Lots of that 50% grey appearing, as in High Pass filter, so I tried blending again with HP-type contrast modes.

Thanks also MBd for your list and ongoing inspiration. You're well down the line and I'm happy to hang onto your coat tails.

I find sharing such a great way of learning. It's good too when I get called out for barking up the wrong tree. Just as long as I learn something, I'm a happy bunny.

 


Dave Straker

Cameras: Sony A7R2, RX100V

Computers: Win10: Chillblast Photo with i7-3770 + 16Gb RAM + Philips 40in 4K; Surface Pro 4 i5

Favourite word: Aha. For me and for others.

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here is the algorithm for vivid light.  IT is a combination of color dodge and color bur Based on the value of a particular pixel. This blend mode combines Color Dodge and Color Burn (rescaled so that neutral colors become middle gray). Dodge applies when values in the top layer are lighter than middle gray, and burn to darker values. The middle gray is the neutral color. When color is lighter than this, this effectively moves the white point of the bottom layer down by twice the difference; when it is darker, the black point is moved up by twice the difference. (The perceived contrast increases.)

 

Blend > 0.5) * (1 - (1-Target) / (2*(Blend-0.5))) +
(Blend <= 0.5) * (Target / (1-2*Blend))

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