Jump to content

Recommended Posts

On 7/16/2017 at 1:34 AM, MartinsRibeiro said:

In Photoshop, you have to:

1 - create two layers

2 - blur the bottom layer

3 - subtract the bottom layer from the upper layer

4 - change the top layer blending mode to Linear Light.

 

On 7/16/2017 at 3:46 AM, toltec said:

That is an interesting approach but not what I would call "Frequency Separation".

I realize this is an old post, but for anyone who might be interested, the steps outlined by MartinsRibeiro are exactly what Frequency Separation is, and presumably the same steps that the AP Frequency Separation filter is actually doing for you behind the scenes (there is more than one way to achieve the same result, but essentially the same).

When you blur the first copy of the image, you're effectively applying a "low pass filter" which removes the high frequency components (the "details") and leaves the low frequency components (the "colors").

When you subtract that blurred version of the image from the second copy, the low frequency components are removed from the second copy, leaving only the high frequency components.  This is equivalent to applying a high pass filter that is the exact inverse of the low pass filter used in the previous step.

So now you have two layers which contain the low frequencies in one layer and the high frequencies in the other layer.  These two frequency ranges have been "separated" out from one layer into two layers.  Setting the blend mode of the top (high frequency) layer to linear light then adds the two ranges of frequencies back together, re-creating the original image.

Share this post


Link to post
Share on other sites
On 6/11/2018 at 12:57 PM, Fotoloco said:

1. Convert your image to LAB mode.

2. Duplicate the layer, and name the lower one "L" (luminosity) and the upper one "C" (color).

3. Go to the channels studio for "L" and click on the "..." for AOpponent, and click "Clear". Do the same for BOpponent.

4. Go to the channels studio for "C" and click on the "..." for Lightness, and click "Clear" and then "Invert".

5. Change the blend mode for "C" to "Color".

6. Duplicate "L" and name the lower one "L blur", then apply a blur filter of your choice (Gaussian or median, etc.) to this layer.

7. Create a new group named "High pass" and place "L" inside it. Then, duplicate "L blur" and place it above "L" (inside the "High pass" group).

8. Go to the channels studio for the copy of "L blur" inside the "High pass" group, click the "..." for Lightness, and click "Invert". Set the blend opacity to 50% (blend mode normal).

9. Set the blend mode for the "High pass" group to linear light, and then rasterize the group if you wish.

 

So how is this done in Affinity Photo for desktop (Mac)? I'm struggling to follow the directions in the Channel Studio for the desktop version.

 

Share this post


Link to post
Share on other sites

Apologies to Lance_G, this does not answer your question directly, but there is a recently posted series of videos on YouTube by D. Straker that covers frequency separation in Affinity Photo. The most technical one ("How It Works, In Detail!") shows, with excellent visuals, how the step-by-step process works for RGB images. The  following link gets you to the series, or search for "InAffinity" and "Frequency Separation." (I have not viewed the more basic videos.)

 


AP 1.6.7, MacOS 10.14.3

Mac Mini, Late 2012, 2.5 GHz Intel Core i5, 8 GB

1.7 betas viewed on early 2015 MacBook Air, 1.6 GHz Intel Core i5, 8GB

Share this post


Link to post
Share on other sites
11 hours ago, Lance_G said:

So how is this done in Affinity Photo for desktop (Mac)? I'm struggling to follow the directions in the Channel Studio for the desktop version.

 

Here you go
I see an issue with changing to LAB. It also changes the color profile of the image. I haven't tested the LAB solution so I don't know if it gives you better results that the traditional one.

Share this post


Link to post
Share on other sites
4 hours ago, MartinsRibeiro said:

Was there anything I was supposed to see here? All I get (on my tablet) is a totally black screen.

John


Windows 10, Affinity Photo 1.6.5.123 and Designer 1.6.5.123, (mainly Photo), now ex-Adobe CC

CPU: AMD A6-3670. RAM: 16 GB DDR3 @ 666MHz, Graphics: 2047MB NVIDIA GeForce GT 630

Share this post


Link to post
Share on other sites
3 minutes ago, John Rostron said:

Was there anything I was supposed to see here? All I get (on my tablet) is a totally black screen.

I get ten seconds of video when I view the post on my iPad.


Alfred online2long.gif
Affinity Designer 1.6.5.123 • Affinity Photo 1.6.5.123 • Windows 10 Home (4th gen Core i3 CPU)
Affinity Photo for iPad 1.6.11.85 • Affinity Designer for iPad 1.6.4.45 • iOS 12.1.4 (iPad Air 2)

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×