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Creating infrared skin tones in Photoshop


wodendigital

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Hello all!

I have a particular problem with a film shoot I am in R&D on at the moment. I need a few of my characters' skin tones to have an infrared quality to it, but want the rest of the scene to be in normal visible light. So it's literally only the skin that is infrared.

See image for reference:

image.jpg

Infrared images of skin have a certain waxy, white, smooth (removal of blemishes because of the lack of colour in the red channel), almost translucent, and have a glow to them. If this was just a still image I was trying to create, it would be simple I would just isolate and mask out the skin area and composite it on an image shot with visible light...but alas it is moving image so everything becomes a hundred times harder.

i am looking for thoughts on filters and colour correction combinations that might successfully create this look in Photoshop, then I can either use the theory in another application like Nuke or Fusion...or even attempt it in Photoshop. A simple fake Infrared channel swapping is not good enough, I need that waxy look. It's not simply a case of colour correction I think.

Any thoughts would be most welcome.

many thanks

Tim

I have listed below how I planned to do it in-camera if snyone is interested.

I have a Methodology to do it in-camera but it's very problematic, and involves using a 3D stereo rig with two cameras, one infrared converted, the other a standard camera. There are many problems to this method, like the difference in focus distance between visible and infrared, the exposure compensation that would be necessary, the issue of getting the right amount of infrared light needed to create a clean image. Monitoring restrictions, weight, logistic and cost of using a 3D rig. Managing to convert a camera to infrared that is 10/12-bit with a wide enough dynamic range necessary. I am looking into converting one of my Blackmagic Cinema Cameras but there is no genlock for shutter sync (but not majorly worried about that as for this purpose I could probably get away with it.

i am also considering VFX workflows Like 3d scanning the talents head and texture mapping a series of infrared image maps onto the 3D model then tracking that onto them over the live action footage. One idea I toyed with was to turn an image into B&W then uses that as a grayscale map to use as a luminance value mask to map an infrared image map over the footage but I doubt it would work Very well if at all, and as soon as you start getting motion blur and or even noise it would throw it out.

Thanks
 

Tom Mann

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Hi Tim -

Here are some semi-random thoughts:

1. Since the actor is almost certainly going to have to be in makeup anyway to achieve the waxy, blemish free look that you want, is achieving a bit of a IR-like white glow with special efx makeup (possibly assisted with a modest amount of PP) out of the question? As I'm sure you know, not only are many different types of normal white makeup available, but so is UV fluorescing white makeup. A bit of this mixed with their normal makeup, and selectively illuminated with small amounts of UV from an appropriate follow-spot would allow you to control the white effect from imperceptible, all the way to God-Glow White, LOL.

Here are some sources of white fluorescing makeup:

http://www.makeupforever.com/us/en-us/make-up/artistic/powder/fluo-night
- - - Note the statement, "...This makeup range comprises of 8 shades including a unique and universal “invisible” white. ..."

http://www.fxsupply.com/uv/uvmakeup.html?PHPSESSID=eea22ip9jdbe82j7nf374guhg6
- - - Scroll down about half-way to their UV-luminous cream makeup (available in white)
============

2. One of the standard, very simple ways to obtain alabaster or porcelein like whitened skin in PS is shown in this link:
http://www.webdesign.org/photoshop/...-skin-effect-in-adobe-photshop-cs6.21908.html

Once you have the face of interest selected in each frame, it should not be difficult to implement the above procedure. Obviously, the best approach is not to attempt to rely on this technique to both remove blemishes and whiten, but just to whiten. The "perfect skin" almost always should start with an actor with great skin, followed by good makeup, then good lighting. The whitening should be the last step.
============

3. It occurred to me that what you are after is only different in some fairly minor details from the usual skin retouching / re-coloration techniques commonly used in video production. No matter whether you want to give the actor perfect skin, and then either tan or whiten it, the general PP techniques are the same. You may already be quite aware of these techniques, but here's a nice website that discusses them:
http://provideocoalition.com/ryoung/story/digital-beauty-treatments
- - - especially the section on "Beauty Box"
http://www.toolfarm.com/blog/entry/skin

HTH,

Tom M
 

wodendigital

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Hi Tom thanks for your lengthy reply, sorry took me so long to get back—busy time of year!

You are right that tis will likely be a joint effort between make-up, lighting and post flow. I would like to mimic the look as much as possible in post to save time on-set but as normally with Infrared a lot of the blemishes are removed by actually shooting infrsred, I will have to combat that on-set just to save me spending months rotoscoping. I have seen and used a lot of the beautifying plugin and programs that work to a certain extent but the quality of the output is usually down to the lighting and resolution of the captured media. I need to be relatively free to shoot on moody light which can seriously affect the quality of those beautybox plugins. It will be, as with all good 'looks' a combination of effects. I don't want that 'Surrogates' look. But a certain amount of smoothing will have to be done so skin tones will have to be good for it to work well.

the UV make up is a very interesting idea. Something worth experimenting with. I haven't tried to use UV lamps in combustion with tungsten/daylight balanced lamps. I would need to be careful with UV pollution both as a colour cast and as colour in the scene. Maybe I could set up some kind of specific spot that is snooted to cover just the skin tones. The glow would only be a subtle effect so maybe it might be better to do it in post but I love the idea of it l....test test test.

thanks for the Alabaster/porcelain look...threats the kind of thing I was looking for, that's great. Will look into it and see how I can manipulate the technique to suit me.

additionally: one thing I would like to look into is a way to change the amount of subsurface scattering on the skin. This I think is one of the main elements to having that waxy look. How plausible this would be for motion footage I don't know. It may well be I have to contact a practical effects artist and do it with prosthetics. If I have to go that route I may as well do most of the effects that way. All food for thought anyway.

thanks for your time.

cheeres

Tim
 
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wodendigital

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Additionally I would like to look at somehow affecting that subsurface scattering amount in the skin (at least faking it somehow). I think the subsurface scattering is helping to create that waxy look as much as the colour tone and the smoothness. How plausible this is to do in motion for a lengthy period I do not know. It may well be it is a prosthetics choice and I have to find a practical effects artist. If that is the road I end up going down a lot of these effects choices would likely be done with that. Food for thought and a little experimentation

this may just be a case of dulling the specular highlights to create that smooth roll off—combination of a make up application of some kind and lighting technique.

image.jpg
image.jpg
image.jpg

Thanks
 
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Hoogle

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lol Tom already stated the tutorial which I Obviously didnt read !!!!! so removed my suggestion
 
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wodendigital

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Ha! Well I've got lots of directions to go in for now. Let me know if anything else springs to mind :)

Thanks for looking.
 

Tom Mann

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Hi WodenD - I'm glad that you have a bit more food for thought. If we think of anything else, we'll post in this thread. You'll be notified by email if you gave a working email address when you registered.

BTW, while I certainly agree that a good part of the waxy look is due to the increased depth of penetration (and hence, the effect of subsurface scattering) at longer wavelengths, I think that the strong decrease in surface (and near surface) spectral reflectivity of blemishes at longer wavelengths is also a major factor, not just the increase in their transmission (ie, increased amount of light they let through to lower layers). Optical reflection and transmission are related, but different.

Please do come back and let us know how it goes.

T
 
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wodendigital

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Tom, yes I fully agree.

I will investigate further. Will post but when I have made a head way...or have more questions :)

Thanks again.
 

wodendigital

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Wondering how possible it is to reconvert image back to standard visible light? Sure would be easier converting to Infrared. If the linear signal from raw is basically grey values with the debayer then adding the RGB to the image, this can be colourised or converted in someway?

Thinking out loud....
 

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