Your best masking techniques.

[KR1156]

Lately there's a lot of work on skin going on, i would love to see everyones effort on an image that requires a lot of masking work, something high-end, like a shot of a female model with plenty of flowing/fly-away hair, etc. Where she needs to be totally silo'd from her background, and placed onto another flawlessly.

I have the perfect image for this, but can't get the photog's permission...does anyone here have any images they would like to provide for learning purposes?

I would love to see everyone's techniques and input, there are a lot of talented ppl on here...i think anyone who is interested in high-end beauty retouching would greatly benefit this "challenge"

-any takers?

[pellepiano]

Heres an example of mine.

http://www.pellepiano.com/studiobild...s/imageb14.jpg

I find the extract tool can give a pretty good start and the Russell Brown Layer Mask method is good but quite timeconsuming.
I shoot against a bluescreen.

[KR1156]

extract is great when you have the contrast to work with, i would love to see how people manipulate channels to get their refined mask,,,what techniques are out there. what people are doing to separate those flyaways from a background with no contrast.

i have the masking book by katrin eisman, which is really good.

[bart_hickman]

Originally Posted by KR1156

extract is great when you have the contrast to work with, i would love to see how people manipulate channels to get their refined mask,,,what techniques are out there. what people are doing to separate those flyaways from a background with no contrast.

i have the masking book by katrin eisman, which is really good.

NO contrast? Well there's got to be some contrast. Here's a pathalogical one to torture yourself with:

http://www.pbase.com/zumbari/image/6...7/original.jpg

Bart

[Daviskw]

Well sure not my best ... bart that is a tough one. I think if I spent a little more time on the puppy's back edge it would not come out too bad... just more work than i want to do now... But if i was of a mind all it would take was a little work on the mask and some blurring.

To get where I am...

Duplicated the background

I used the pen to make a outline . Then converted the outline to a alfa channel. Then used that channel along with the extraction tool.

Made a selection mask of the extracted dog. and attached it to the duplicate layer... then erased the extracted layer.

Inserted my picture in the middle.

Butch

[bart_hickman]

Excellent job Butch. I didn't post my extracted version because it's a lot harder to explain than it is to do.

I usually start with the extract tool, then plan B is the background eraser. In this case I didn't think extract would work, so I skipped to the BGE which handled about 70%. 20% was image-based masking, 10% was manually erasing with a stipple brush (the part of the dog that has no contrast at all).

First attachment shows the beginnings of BGE work. After using the BGE, I do the rest of the extraction using other methods and I'll focus on a section extracted using image-based masking (more or less what Russell Brown describes in his video tutorial.)

In the places where the BGE doesn't work well, this image has some contrast information in all color channels,not just one, so I use the info from all three. The second attachment shows how that works.
1. Original
2. Sample the hair color near the edge of the hair, but where the hair completely blocks the background. Floodfill a new layer with this color and set blend mode to difference--now the edge hair is black, and everything else is some other color.
3. Add channel mixer--set the coefficients to 50,50,50 Could have done 100,100,100--the import thing is they are equal because I'm using information from all three channels equally. Choose monochrome to convert the color difference into a greyscale image.
4. Add a levels control to accenuate the contrast
5. Use a brush to clean the areas away from the edge of the hair. Good idea to make a marquee selection in case you accidentally slip while brushing.

That's my 2-minute tutorial on converting information from all channels into a single mask.

There's more finish-up work I'll describe later--gotta go right now. As a preview, the final attachment is my final result.

Bart

[Kraellin]

this is all mask, back and forth, black and white. i added the neutral gray to really show the work. masks are great because you never have to alter the work itself, just the mask.

craig

[Gary Richardson]

This is mine, made from the red channel.

Got it something like, then adjusted the mask using levels. Final tweaking done with a low opacity black/white brush.

[BillFrey]

My masking didn't turn out great, so I used hair brushes to fix it up.

[Ying]

I have a question: What if you need to extract a grey object from grey background?

I had to do this type of work a while ago and ended up creating custom clipping paths, which took forever to draw and adjust!

Attached is an example:

[Gary Richardson]

In this case there was quite good contrast, and the extract tool did a passable job, needed a little hand touching with eraser and history brush, but whole job only took about 5 mins.

Of course if getting in really close, a clipping path will be the route of choice because of the crisper edge definition.

[bart_hickman]

Well I didn't challenge you guys at all--nice work one and all. Okay, I'll have to dig up something more difficult.

Bart

[Kraellin]

Got it something like, then adjusted the mask using levels.

now that's an interesting idea, gary. i sometimes blur the masks but hadnt thought that much about using adjustment layers on them. good tip!

bart,

we've had some wild challenges like this in the past. it's one of those areas that i wish psp did a better job of. i did notice when i was working on this image that psp xi has changed some things in the magic wand, so going to have to study that a bit more. it's always struck me a bit odd that the human eye can discern the differences necessary but that the graphic editors cant seem to very well. ah well, gives the coders something to work on, i suppose

craig

[bart_hickman]

Originally Posted by Kraellin

we've had some wild challenges like this in the past. it's one of those areas that i wish psp did a better job of. i did notice when i was working on this image that psp xi has changed some things in the magic wand, so going to have to study that a bit more. it's always struck me a bit odd that the human eye can discern the differences necessary but that the graphic editors cant seem to very well. ah well, gives the coders something to work on, i suppose

craig

Hi Craig,

Two reasons for this. 1) you (your brain) interpolates to find patterns where none exist, 2) not only can you see the boundary between color changes, but you can also see the boundary between texture changes.

In both of these cases, I just get a stipple brush and create the boundary I think I see in my mind's eye.

Photoshop is very productive for multistep extractions like this--the UI seems really geared for effortless manipulation of masks and selections and conversions between paths/selections/masks.

As for PSPXI, I was put off by the fact that the levels adjust tool has had the output slider removed--something I use quite a lot.

Bart

[Kraellin]

bart,

yes, and the mind plays tricks at times but yes. i think it also may be a flaw in the entire digital system, at least the rgb system. this is something i've been studying recently and havent fully grasped yet. it's somewhat an inherited system from a time when computers were much more limited. it's probably also why LAB came about; someone else felt the same way, apparently. it's a bit limited that we divide the entire light spectrum into only rgb; why not rgbcmyk...or even more? i'll work on it

as for the levels tool, i noticed but wasnt concerned. i actually use levels a lot less than most here. and they did add white/black/gray points to it. i suppose that was their solution to the output part. but yes, in general, i hate when they take away a favorite function. you could always put it back, you know. there is that customization feature in psp. i've added back quite a few things.

craig

[bart_hickman]

Originally Posted by Kraellin

bart,

yes, and the mind plays tricks at times but yes. i think it also may be a flaw in the entire digital system, at least the rgb system. this is something i've been studying recently and havent fully grasped yet. it's somewhat an inherited system from a time when computers were much more limited. it's probably also why LAB came about; someone else felt the same way, apparently. it's a bit limited that we divide the entire light spectrum into only rgb; why not rgbcmyk...or even more? i'll work on it

The interpolation or extrapolation I'm talking about arises from our knowledge of how something should look--this is knowledge the computer doesn't have. So it's really psychological. Color space won't help here. What you'd need is for photoshop to be able to look at a photo and actually recognize things--there's a rock, there's a person, there's an eye, there's some hair, etc..

I think a better form of image compression would actually be helpful--jpeg tends to make a blocky mess of color. Jpeg2000 is a lot nicer in this regard. Don't know how long it'll be before the world starts using that instead of jpeg.

as for the levels tool, i noticed but wasnt concerned. i actually use levels a lot less than most here. and they did add white/black/gray points to it. i suppose that was their solution to the output part. but yes, in general, i hate when they take away a favorite function. you could always put it back, you know. there is that customization feature in psp. i've added back quite a few things.

craig

The white/black/grey points is useful, but PSP already had that capability in a separate tool (with similar name.) In fact the white/black/grey points tool in the adjustment layers is a limited version of the older tool.

That output slider on the levels adjust is totally gone--can't be added back. I actually submitted it as a bug to Corel because there's a blank area in the dialog box where it looks like the slider should go. At least they added a histogram to the levels and curves.

The other handy feature that was dropped was you can no longer use the eyedropper to place points on the curve in the curves tool.

Bart

[pavel123]

Originally Posted by Ying

I have a question: What if you need to extract a grey object from grey background?

I had to do this type of work a while ago and ended up creating custom clipping paths, which took forever to draw and adjust!

Attached is an example:

I this case magnetic lasso and then polygonal lasso do a fairly good job, 5 min tops.

[pavel123]

Used red channel, levels to increase contrast, brushes, another level correction, convert to selection, copied to a separate layer, eraser.

[bart_hickman]

Extract the dead tree in the foreground. I'll post my result later after I get home and have a chance to work on it. This one would mainly be a combination of BGE and polygonal lasso for me--no shortcuts I can think of. Tell us your clever shortcuts! Maybe the saturation channel might have some info since the dead tree is pretty much colorless whereas the background has color.

http://www.pbase.com/zumbari/image/6...1/original.jpg

Bart

[Daviskw]

Man Bart... what a pain!!!

Well... I started with a red channel copy...levels... then I kept both the red copy and the RGB on screen... then just painted with black and white where needed... slowwww

Maybe some one has a better way.

Butch

[bart_hickman]

Yet another good one Butch.

Well finally got a free moment. Here's mine. About 90% background eraser with magnetic/polygonal lasso in places where the shady parts of the snag were identical in color to the background.

Unlike masking, the BGE tries to decontaminate BG colors that have mixed with the fringes of the foreground. However, it's not perfect in textured situations like this, plus I had some low opacity background leftovers. To avoid manual erasing as much as possible, I create an inverted mask from the extraction (ctrl-click the snag thumbnail, add layer mask to copy of new background, ctrl-i to invert the mask). Sometimes I set the blend mode to screen, but in this case normal was fine.

I attached the layer palette to illustrate.

I also did a second mini-extraction on the new background so the snag appears to emerge from behind the trees--that's just one more layer. I left it out of the layer palette I attached for simplicity.

Bart

[Gary Richardson]

Another BGE user here. Tried all sorts of different approaches, but none gave as good a result. Found myself having to do quite a lot of touch ups with the history brush, and lots of on the fly tolerance adjustments with BGE.

Not totally happy with result, if this was anything but an exercise I think I'd have to play with it some more.

[Kraellin]

hehehe, you are definitely a sadist, bart

just one thing here on the examples posted from all, i'd like to see these on a solid, neutral background, so we can really see how good these are. i know one technique mentioned here on RP for doing these recommended finding a background where your extraction 'flaws' would not show as much. but here, for this exercise, i'd like to see them on solid backgrounds.

craig

[Gary Richardson]

Wish you'd asked that before I'd flattened image for posting Craig.

I've only got a small hard drive (he says hanging his head in shame), so I don't keep the layered files for exercises like this. (Mostly I don't keep the files after posting either).

[Peter S]

Originally Posted by Gary Richardson

I've only got a small hard drive (he says hanging his head in shame).

I keep getting spam Emails about this sort of thing, I try to ignore them and get on with life

[Daviskw]

Hi craig

Never flaws... just selection choices....

Butch

[plugsnpixels]

For those who prefer a plug-in approach for the sake of speed, Digital Film Tools just released EZMask this week. The example with the girl on the page is the very first time I tried it, and it only took a little practice to achieve the results shown.

[bart_hickman]

Originally Posted by plugsnpixels

For those who prefer a plug-in approach for the sake of speed, Digital Film Tools just released EZMask this week. The example with the girl on the page is the very first time I tried it, and it only took a little practice to achieve the results shown.

That particular example is pretty easy for either extract or BGE. I takes about 30 seconds with the extract filter in CS2 which (along with the BGE)--just use a fat brush and default settings. Extract has all the same defringing/decontamination technology although Adobe seems to go out of their way to not mention this fact (it's mentioned briefly in the manual buried in the text.) I'll give EZMask a try on some more difficult ones and see how it compares.

There's another one similar to EZMask (don't know if it's better) for less $ here:
http://www.imageskill.com/background...ndremover.html

The imageskill tool works pretty well although I'd say it's only roughly similar in performance to the photoshop extract tool.

Bart

[bart_hickman]

Originally Posted by Kraellin

hehehe, you are definitely a sadist, bart

just one thing here on the examples posted from all, i'd like to see these on a solid, neutral background, so we can really see how good these are. i know one technique mentioned here on RP for doing these recommended finding a background where your extraction 'flaws' would not show as much. but here, for this exercise, i'd like to see them on solid backgrounds.

craig

The masked screening and/or multiplying (I only did screening as shown in my first post) I do takes care of any leftover old colors so the new BG color is automatically mixed into the fringes or semi-transparent portions of the extracted object.

In practice, I hardly ever have to be this careful because the new background is generally more forgiving than a pure color.

Bart

[plugsnpixels]

Bart, I've also got Background Remover on hand to add to the site--I need to get to that. As a Mac user I'm a bit slower firing up the Windows plug-ins, but I do run Windows on a MacBook, so...