RetouchPRO

Go Back   RetouchPRO > Tools > Software
Register Blogs FAQ Site Nav Search Today's Posts Mark Forums Read


Software Photoshop, Lightroom, Paintshop Pro, Painter, etc., and all their various plugins. Of course, you can also discuss all other programs, as well.

FilterMeister - Color Theory and Conversions

Reply
 
Thread Tools
  #101  
Old 04-29-2006, 12:03 PM
Stroker's Avatar
Stroker Stroker is offline
Senior Member
 
Join Date: Jan 2005
Posts: 370
Yeah, I've been slacking lately all around. So much junk to do.
- more High Pass tutorials
- extracting difference tutorials
- variable frequency tutorials (variable medium frequencies rock)
- several filters to polish as a direct result of this thread
- I figured out how Photoshop handles hue and sat in Lab mode so Lab filters can be made PS friendly
- playing with several ideas for flesh tweaking
- new water softner to install
- dishes and laundry to do

It is possible to RGB > CMYK the way Photoshop does it. You will have to get into ICC and junk to do it. Color dot Org? I'm not entirely sure, but I do know it's not a journey I don't want to take.
Reply With Quote top
  #102  
Old 05-02-2006, 11:47 AM
Cameraken's Avatar
Cameraken Cameraken is offline
Senior Member
 
Join Date: Feb 2005
Location: Lancashire (UK)
Posts: 1,158
The more I read on CMYK the more I realised it was dependant on ICC profiles. And I don’t want to get into that stuff either.

I read the new tutorials. I see you put the Silly Difference Trick in there. I was amazed when I first saw that used at PST and I downloaded the instructions from the Asylum.

There has been a lot of discussion recently regarding saturation changes with blending modes (dodge and burn) I have found that a Select All > Copy Merged > Paste
Then set blending mode to Luminosity seems to work OK. (Turning off the adjustment layers)

Thanks for the new Tutorials Stroker.


Next Project.

My next project is to try to simulate the Healing Tool.

I would like to get the results of the healing tool without having to stamp my way all over the picture.
I have scoured the web for a formula but have had no success.

This is what I usually do.
Create a 50% grey layer and add noise matching the photo. I then use this as my source to heal onto the picture. It would be nice to do this with FM because it is quite time consuming. It would also need a radius (Or brush size) slider.

It seems to involve a layer of noise (matching the source) but taking the luminosity of the original somehow.

I have found the Perlin noise command implemented by Ron Chambers

http://groups.yahoo.com/group/FMML/message/707

Quote:
perlinNoise1D()
perlinNoise2D()
perlinNoise3D()
produces one/two/three-dimensional perlin noise. There will be parameters
for persistance, octaves and random seed.

This feature should be implemented but there is nothing in the Wiki (As usual) and I’m not sure what to put into the brackets. But I get a Symbol ‘perlin’ Undefined error. So maybe this was never implemented.

There is noise code here

http://freespace.virgin.net/hugo.eli...s/m_perlin.htm

Quote:
function IntNoise(32-bit integer: x)

x = (x<<13) ^ x;
return ( 1.0 - ( (x * (x * x * 15731 + 789221) + 1376312589) & 7fffffff) / 1073741824.0);

end IntNoise function

So it looks quite easy to make my own. But I am not sure how the healing tool uses this.



Ken.
Reply With Quote top
  #103  
Old 05-03-2006, 04:22 PM
Stroker's Avatar
Stroker Stroker is offline
Senior Member
 
Join Date: Jan 2005
Posts: 370
Perlin Noise is fun. You can already do it with Photoshop's stock tools, or even FM.

There are two main things that define Perlin Noise: pseudo-random and interpolation. Now, pseudo-random really matters when you are into animating the texture. For the vast majority of 2d work, don't really need pseudo-random. The interpolation for PNoise is bi-cubic, sometimes smoother and sometimes not.

Armed with that and some sub-pixel savvy, we can hack PNoise in Photoshop.
- New document and fill with 50% grey.
- Filter > Noise > Add Noise to taste.
- Rectangular Marque and select a small square.
- Copy and paste small square to new layer.
- Preferences and make sure interpolation is set to Bi-Cubic Smoother
- On the small rectangle layer, Edit > Transform > Free Transform and make it huge.

Once you commit the Free Transform, watch the magic as Bi-Cubic Smoother kicks in. Tada. Instant Perlin Noise.

To do this with FM, use iget(). Fill one of the buffers with random noise, then use iget() to sample sub-pixels. I might have a working sample in my FM archives somewhere.

BBL
Reply With Quote top
  #104  
Old 05-03-2006, 05:22 PM
Stroker's Avatar
Stroker Stroker is offline
Senior Member
 
Join Date: Jan 2005
Posts: 370
Okay, here is my first attempt at PNoise using iget().

Code:
%ffp

ctl(0): "Size",Range=(2,64),Val=32
ctl(1): "Seed",Range=(1,100),Val=50
ctl(10): combobox(vscroll),action=preview, color=#FFFFFF,fontcolor=#0000ff,
pos=(325,40),size=(70,200),
text="Nearest Neighbor\nBisquare\nBicosine\nBilinear\nBicubic",val=4
ctl(100):STATICTEXT, pos=(325,70),"", fontcolor=black

ForEveryTile:
{
int x,y,beginsizex,beginsizey;
int finalvalue;
float p1,q1;

beginsizex=(X*1/ctl(0));
beginsizey=(Y*1/ctl(0));
rst(ctl(1));

for (y=0; y<beginsizey+1; y++){
for (x=0; x<beginsizex+1; x++){
tset(x,y,0,rnd(0,255));
}//x base
}//y base

for (y=0;y<Y;y++){
for (x=0;x<X;x++){

p1=(float)x*beginsizex/X;
q1=(float)y*beginsizey/Y;

finalvalue=iget(p1,q1,0,1,ctl(10));

pset(x,y,0,finalvalue);
pset(x,y,1,finalvalue);
pset(x,y,2,finalvalue);

}//end x
}//end y
return true;
}
While it illustrates the idea, it is fraught with bombs. The first bomb being the 2d range. That is, uses 0 to X instead of x_start to x_end. For larger images there will be a speed difference. A real bomb is how the division is handled. The division in the code is *very* half-baked. The division also needs to take scaleFactor into account.

Man, and that's not even getting into fractal or turbulent noise. When will it end?

I adore the Silly Difference Trick. While it is mostly a bauble, the derived techniques are very cool. Maybe tonight I'll toss another one or two up after I get some dishes done.

I'm not exactly sure what the Dodge & Burn thing is, but I have my suspicions. If it's what I think I think it is, maybe I'll toss some of my notes out for ya'll. It's basically selectively lightening and darkening by painting, right?
Reply With Quote top
  #105  
Old 05-03-2006, 07:59 PM
Cameraken's Avatar
Cameraken Cameraken is offline
Senior Member
 
Join Date: Feb 2005
Location: Lancashire (UK)
Posts: 1,158
Stroker


Quote:
I'm not exactly sure what the Dodge & Burn thing is, but I have my suspicions. If it's what I think I think it is, maybe I'll toss some of my notes out for ya'll. It's basically selectively lightening and darkening by painting, right?
Yes. You are correct. But I thought this applied to your ‘High Pass and Saturation’ Tutorial as well.
The latest threads are here

http://www.retouchpro.com/forums/non-retouchpro-resources/13350-visual-reference-dodge-burn-tech.html
And especially Edgeworks reply here
http://www.retouchpro.com/forums/photo-restoration/13455-new-layer-50-grey-overlay.html

I have not had chance to try the code yet. I will play with it tomorrow.


Ken.
Reply With Quote top
  #106  
Old 05-04-2006, 03:26 PM
Cameraken's Avatar
Cameraken Cameraken is offline
Senior Member
 
Join Date: Feb 2005
Location: Lancashire (UK)
Posts: 1,158
Stroker

Wow! That code is brilliant.
It’s very interesting to see the different interpolation methods in action. And it also shows how clouds can be made from noise. It’s even a good background maker. (I just added R,G,B Checkboxes to get coloured effects. It really needs to be changed to be run three times, once for each channel)

Iget is a very powerful command. Interpolation methods: 0 for nearest neighbor (no interpolation), 1 for bisquare, 2 for bicosine, 3 for bilinear and 4 for bicubic.

The noise is quite large compared to PS. 2 on this scale is equivalent to about 120 on PS noise filter scale.

Ken.
Reply With Quote top
  #107  
Old 07-04-2012, 05:03 PM
4N6site 4N6site is offline
Member
 
Join Date: Jul 2012
Posts: 46
Arrow Re:FilterMeister -Color Theory [fixes broken link]

The mentioned color deconvolution plug-in is from 4N6site.com. Check out some examples here.
Previous posts contain outdated links, but the plug-in is available through 4N6site.com.
You can also contact the site if you want to be absolutely sure you get the maximum out of the plug-in!

Quote:
Originally Posted by Cameraken View Post
http://home.planet.nl/~ber03728/4N6site/main.htm
There is some interesting stuff there. Roll your mouse over the picture at the bottom of the page. And read the ‘Explaining Colour Deconvolution’ I think you will find it interesting. His link to http://www.couleur.org/ is interesting too.
I have requested His filters.

Ken
Reply With Quote top
Reply

  RetouchPRO > Tools > Software


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
Color Space conversions Reimar Photoshop Elements Help 4 01-16-2004 06:58 AM
Batch Raw conversions in PS CS okplayer Software 0 12-19-2003 01:03 PM


All times are GMT -6. The time now is 10:11 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