RetouchPRO

Go Back   RetouchPRO > Technique > Photo Retouching
Register Blogs FAQ Site Nav Search Today's Posts Mark Forums Read


Photo Retouching "Improving" photos, post-production, correction, etc.

question about frequency separation method

Reply
 
Thread Tools
  #1  
Old 02-18-2011, 03:53 PM
Caravaggio Caravaggio is offline
Senior Member
 
Join Date: Jun 2007
Location: New York City
Posts: 235
question about frequency separation method

I like the frequency separation technique and am starting to use it and get more familiar with it. The only problem I have is where areas of extremely strong contrast meet or "edges". If I clone over those areas on the high frequency layer, it introduces a tonal change into the image when all I wanted was the texture because some of the tonal and color information is also stored on that layer. Generally I just avoid those areas as it creates a mess and do them separately on another layer above the split that doesn't have a frequency separation. I have tried sampling a color and painting it in on the low frequency area in the problematic areas, but that doesn't seem to give me good results and often makes it worse.

Does anyone have any advice or suggestions for dealing with areas of high contrast on a frequency separated image?
Reply With Quote top
  #2  
Old 02-18-2011, 04:30 PM
mistermonday's Avatar
mistermonday mistermonday is offline
Moderator
Patron
 
Join Date: Dec 2005
Posts: 3,028
Re: question about frequency separation method

Caravaggio, try posting a sample of that specific area. It may be that you need to chose a different separation radius. In fact in most retouches, a single separation radius is not suitable to do the entire image. Also depending on the image, you may want to use an asymetric frequency separation where the color is completely separated on the LF layer and the HF layer has texture but absolutely no color.
Regards, Murray
Reply With Quote top
  #3  
Old 02-18-2011, 05:02 PM
Caravaggio Caravaggio is offline
Senior Member
 
Join Date: Jun 2007
Location: New York City
Posts: 235
Re: question about frequency separation method

Here is an area that would cause problems because of the change from the pink object to the blue wall and the shifts in tonal value. The original is a very high res, 16 bit image.

I don't know how to do an asymetric frequency separation. Can you point me in the right direction? Thanks.
Attached Images
File Type: jpg image2.jpg (78.5 KB, 201 views)
Reply With Quote top
  #4  
Old 02-18-2011, 08:06 PM
mistermonday's Avatar
mistermonday mistermonday is offline
Moderator
Patron
 
Join Date: Dec 2005
Posts: 3,028
Re: question about frequency separation method

To make a frequency separation in which the color is completely separated from the HF layer as well, do the following:
- Create 3 copies of layer to be separated and name them LowFreq, Color, HighFreq (bottom to top).
- To the bottom copy (LF), desaturate the layer (Image>Adj>Desat or Crtl+Shift+U), and then immediately go Edit > Fade Desaturation and change the Blend Mode from Normal to Hue.
- Next to this same layer apply the Gaussian Blur as you normally would.
- Now select the top layer (HF). Change blend mode to Linear Light. Once again, Desaturate the layer and Edit > Fade Deasaturation and change the Blend Mode to Hue.
- Next do Image > Apply Image using the LF layer as the source as the source just as you do in a normal freq separation.
- Finally, select the middle copy (Color) Layer and change its blend mode to Color and hit Ctrl+E to merge it down onto the LF layer.
Your separation is now complete.
You can experiment by sampling texture with the healing brush and stamoing it on another area. You will heal with texture only. You still need to choose your Radius of separation wisely because you can still make a mess if you are not careful.
Regards, Murray
Reply With Quote top
  #5  
Old 02-18-2011, 09:38 PM
chillin's Avatar
chillin chillin is offline
Senior Member
 
Join Date: Sep 2006
Location: The Golden State
Posts: 1,324
Blog Entries: 1
Re: question about frequency separation method

Could you be more specific as to what you intend to do with the posted sample?
Reply With Quote top
  #6  
Old 02-18-2011, 10:04 PM
Caravaggio Caravaggio is offline
Senior Member
 
Join Date: Jun 2007
Location: New York City
Posts: 235
Re: question about frequency separation method

Quote:
Originally Posted by chillin View Post
Could you be more specific as to what you intend to do with the posted sample?
Its part of a product shop, more or less already finished. I just posted it because it seemed to be a good illustration of the type of area I was having trouble with using frequency separation, areas where there is a sudden large shift in either color or luminosity or both.

Murray, I am liking the asymetric separation. Thanks a lot for the detailed explanation. I am playing around with it now and getting better results although sometimes it doesn't always work right so I assume I am not always choosing the right radius.
Reply With Quote top
  #7  
Old 02-19-2011, 12:18 AM
Aladdin's Avatar
Aladdin Aladdin is offline
Senior Member
 
Join Date: Jul 2008
Location: NJ/NY
Posts: 444
Re: question about frequency separation method

What radius you guys talking about, the Gaussian blur?
Reply With Quote top
  #8  
Old 02-19-2011, 12:30 AM
Caravaggio Caravaggio is offline
Senior Member
 
Join Date: Jun 2007
Location: New York City
Posts: 235
Re: question about frequency separation method

Quote:
Originally Posted by Aladdin View Post
What radius you guys talking about, the Gaussian blur?
Yes, the gaussian blur radius.
Reply With Quote top
  #9  
Old 02-19-2011, 04:55 AM
ashphotoart's Avatar
ashphotoart ashphotoart is offline
Senior Member
 
Join Date: May 2008
Location: India
Posts: 301
Re: question about frequency separation method

Murray, its very helpful post from you. nice technique to sepereate the colors from textrure. Even if we use small radius in standard seperation, some color (little) remains on HF Layer. now its very neat processing of texture with Asymetric Seperation.
Reply With Quote top
  #10  
Old 02-19-2011, 05:19 AM
Der_W's Avatar
Der_W Der_W is offline
Senior Member
 
Join Date: Jul 2009
Location: Germany
Posts: 558
Re: question about frequency separation method

Just to make sure I'm getting the problem right: when you're doing a Gaussian blur based separation to fix problem areas in your image, once you work on areas of high contrast, you run into problems?

The first thing I'd try then would be to use something different from Gaussian blur to create the separation.
E.g. the "Filter"-"Noise"-"Median" preserves (especially round) edges pretty well. Or you could try the "Filter"-"Blur"-"Surface Blur". Possibilities are nearly endless :-)!

But if the asymmetric separation works, that's great as well, I just thought this could give you even more flexibility :-).
Reply With Quote top
Reply

  RetouchPRO > Technique > Photo Retouching


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
IHP related question. nebulaoperator Photo Retouching 36 08-24-2011 05:58 AM
Extended frequency separation fraiseap Photo Retouching 16 12-31-2010 01:33 PM
Frequency Separation In Workflow nowheremanphoto Photo Retouching 13 11-02-2010 04:56 PM
question about a Katrin Eismann method jenjen Photo Restoration 11 02-03-2006 11:05 PM
RGB separation on 2 separate areas tatrader Hidden Power Support 1 03-09-2005 12:32 PM


All times are GMT -6. The time now is 02:59 PM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
SEO by vBSEO ©2011, Crawlability, Inc.
Copyright © 2016 Doug Nelson. All Rights Reserved