Gaussian Blur and the High-Pass Filter - What gives?

[byRo]

As we say in Brazil - they're just the two sides of the same coin.
(PS 7.0 - but applies everywhere) [details]

[Ed_L]

I guess Brazil has at least one good teacher. Thanks for the lesson. I'm waiting for the next ones.

Ed

[DannyRaphael]

Pixel math unleashed. This begs for an action for the layer setup!

Like Ed, I'm looking forward to future installments. Fine work, sir.

~Danny~

[Gary Richardson]

Great tutorial Ro, not sure just how much use it will be, but it sure gives you an insight into how these filters work. Looking forward to the next, where my reservations will no doubt be answered.

[byRo]

Originally Posted by Gary Richardson

.... not sure just how much use it will be, but it sure gives you an insight into how these filters work. Looking forward to the next, where my reservations will no doubt be answered.

Sure thing, Gary.
Like I said in the tutorial, this was just the groundwork, the good stuff starts in the next one.
byRo

[vinniesworld]

Thanks for the tutorial, very interesting.

[kiska]

byRo, in the tut you referred to another tut '.....unclip the colors'. I searched with no luck. A little help?
thanks
kiska

[byRo]

Originally Posted by kiska

byRo, in the tut you referred to another tut '.....unclip the colors'. I searched with no luck. A little help?
thanks
kiska

Sorry about that, I haven't yet mastered the fine art of tutorial formatting.
This is the one: Skin tone correction - Unclipping

byRo

[kiska]

Thanks, I got it.
kiska

[Stroker]

"Photoshop does not have a direct blending option for subtraction"

Linear Dodge, but it's 'upside-down'.
Just invert.

Linear Burn = Addition

Linear Light = LD/LB
(although, I've noticed some funkiness at the extremes)

I am, of course, open to corrections.

Excellant article on High Pass for some more nitty-gritty:
http://www.3dgate.com/techniques/200...0625hajba.html

[byRo]

Hi there, Stroker - welcome in

Originally Posted by Stroker

"Photoshop does not have a direct blending option for subtraction"
Linear Dodge, but it's 'upside-down'.
Just invert.

Quite true, linear dodge does do subtraction, however I would refer you to observation 1 (at the end of the tutorial). In this case we are using a system where the pixel values are considered as going from -128 to +127. The Linear Dodge works using 0 to 255.
The basic difference is that if we take two identical images and apply the Linear Dodge we will end up solid black, while in the (more complicated) method used here we end up with mid-gray.

Originally Posted by Stroker

Excellent article on High Pass for some more nitty-gritty:
http://www.3dgate.com/techniques/200...0625hajba.html

Thanks - this was indeed one of my sources of inspiration and I had lost the link.

byRo

[Cameraken]

Hi Rô.

Thanks for another great tutorial. The link mentioned above is now dead.
Do you still have this info?

Quote ”Next up:
– choosing the radius, without the guesswork”

I had difficulty finding this Tutorial. The link is here
http://retouchpro.com/tutorials/?m=show&id=149


Ken.

[byRo]

Wow, I am feeling lucky today!

Did a Google for 3d high-pass texture and the article was first on the list.
http://www.gamasutra.com/features/20.../hajba_pfv.htm

Well worth a good read.

Rô

[Cameraken]

Thanks Rô. I Got it.

I had googled “Photoshop High Pass”
That search found a link to gamasutra but took me to a log in page? So I gave up with that link.

Ken

[pure]

if we use it so often, why is there no "real" combined filter for this kind of repair program, i wonder.

like one filter for diff. steps: "select > blur > highpassing"