9. Mixed Pyramids

Strangely enough if you will, we’re allowed to mix blurring kernels and still the equations work. If you remember: 5. Combined use of different blurring kernels, I’ve found out that:

(SB - GB) = E; (Eq. 9.1)

If we modify the assumptions of the Pyramid decomposition as follows:

U₀ = O; (Eq. 9.2)

U₁ = SB₁(O); (Eq. 9.3)

U₂ = GB₁(O); (Eq. 9.4)

we end up with a 2 level decomposition with:

D₁ = U₀ - U₁ =O - SB₁(O) = T; (Eq. 9.5)

Like we know from eq. 5.4.We then have:

D₂ = U₁ - U₂ =SB₁(O) - GB₁(O) = E; (Eq. 9.6)

which comes from eq. 5.3. So, D₁ is a frequency layer of a mixed decomposition which contains, and hence will be able to enhance,Texture alone; and D₂ is a frequency layer of a mixed decomposition which contains, and hence will be able to enhance, Edges alone.

Here are the difference layers:

(Fig 9.1) O - SB₁(O) = D₁, the texture only detail layer (SB Radius=3,Threshold=16).

(Fig 9.2) SB₁(O) - GB₁(O) = D₂, the edge only detail layer (GB Radius=2).

I’ll show you the full Channels and Layers palettes:

(Fig 9.3) Channels and Layers palettes of a Mixed Pyramid.

Then I’ll add the same curve adjustments layer clipped to the D_n and play with sliders. Here is an example version:

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"Shadow/Highlights" clarification please George Machen 2009-01-07 01:58:49 > 8. Bilateral and WLS Pyramids > > ...Shadow/Highlights with SB (instead of GB) in its > “engine” gives the same halo-free look by the way... I don't have CS4. Are you saying that its Shadow/Highlights dialog now features an option to choose whether it uses Gaussian or Surface Blur? If not, what did you mean exactly in this statement? Thanks! (G-R-E-A-T write-up, Davide!) Répondre

Davide 2009-01-07 22:53:37 Hi George, I'm glad you liked it! No, unfortunately there's no GB/SB option in CS4. But you can always custom build your Shadows/Highlights: for instance, create a curve adjustment layer to lighten the picture, then add a luminosity mask to it (or choose the channel that better suits the image needs and use it as a mask). Now you can experiment using GB and SB for blurring the mask: the first one gives you a standard Photoshop S/H feeling, while SB (as long as the algorithm doesn't reverse) shows less or no halos. Ciao, Davide Répondre

Alexey Rybakov 2009-01-07 19:58:18 Thanks for nice article with informative illustrations and examples. I'll glad to read more if you'll develop this farther. Répondre

Re: "Shadow/Highlights" clarification please Stephen Marsh 2009-01-08 12:48:48 Thank you Davide, this is a great exploration, I am eagerly awaiting some actions! George, I presume that Davide is referring to manually simulating what the Shadows/Highlights command does. Dan Margulis described a method for this and one of the Applied Color Theory list members created an action. This action is available to list members from the files section. Margulis PSU ON2004.atn http://tech.groups.yahoo.com/group/colo rtheory/files/ How to re-create the Shadow/Highlight effect of Photoshop CS as described by Dan Margulis in the Oct/Nov issue of Photoshop User titled "Making Two Ends Meet", pg. 44-47. Regards, Stephen Marsh http://members.ozemail.com.au/~binaryfx/ Répondre

Bravissimo !!! Andrea Baldini 2009-01-08 23:02:13 Devo dire che é una roba incredibile ! Davvero superba la genialità del progetto, non avevo mai visto nulla di simile! Complimenti anche per le illustrazioni realizzate molto bene. Spero che l' articolo venga tradotto anche in italiano. Complimenti ancora, Saluti Andrea Baldini Répondre

good work Jack 2009-02-10 23:13:44 I'd love to test the actions when you create those. Also it would be nice to see samples on photographs as apposed to the painting your using here. It's difficult to see the sharpening. Répondre

thank you! Timo Kirves 2009-03-14 17:51:02 Dear Davide, The whole series of your techniques open dramatically better chances to succesful fine art photographic prints with todays inkjet printers. I work as a photographer and instructor in Helsinki, Finland, working on both own and colleagues´photographic prints. Thank you for shearing this work of yours with the rest of community. Best Timo Kirves Répondre

Davide 2009-03-14 22:48:29 Dear Timo, thank you very much for your comment, knowing that some of my thoughts may help someone out there getting better results and enjoying his pictures is a great reward for me. I wish I had more time to explore other interesting topics - I've something about local contrast in mind but I'd like to dig a bit deeper before publishing. Kind regards, Davide Répondre

Thanks Davide Miriam Calzada 2010-05-18 00:39:32 Hola, mi nombre es Miriam soy fotografo. Vivo y trabajo en Republica Dominicana. He disfrutado mucho toda esta informacion que ofreces. Trabajo por años con Hasselblad y pongo mucho interes en cualquier forma de perfeccionar mi trabajo. Especialmente viniendo de un profesional como tu. Atentamente. Miriam miriamcalzada.com Répondre

Thank you Miriam! Davide Barranca 2010-06-01 09:23:46 It's a great gift to read feedbacks like yours! I've seen the images in your website, and I'm sure the actual prints must be really gorgeous. Thanks again ad all the best, Davide Répondre

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