Complex hair selection

[bart_hickman]

Hi Ken,

No problem, but I think I'm going to give you the full technique I use for transplanting fuzzy and/or semi-transparent objects from one arbitrary background to another (as opposed to moving between two similar backgrounds or plain color backgrounds which has been explained very well already.)

It's sort of a tutorial I've been working on here and there for about a week, but now I think I'll finish it up using the nice hair example from this thread. I'll post a link to it sometime later this weekend.

Bart

[Ken45140]

Bart: that is super. I am eagerly awaiting and I'll bet others would like to know it also.

Thanks,
Ken

[bart_hickman]

Okay, here it is:

http://home.comcast.net/~zumbari/Tut...n_tutorial.htm

I've only tested it on a couple situations including the one in this thread. However, the math implies it should work in a huge variety of situations. It should even work with translucent objects (such as bug wings or bridal viels), but I haven't taken the time to test it on things like that. When I do, I'll add that to the tutorial.

Bart

[Ken45140]

Bart:

Great work, and a very nice technique.

The good news is that I successfully removed the fringe.

The bad news is that I probably cannot recreate my steps, AND, I also can not for some reason put the black background behind the defringed image.

I believe this is so because I am still getting familiar with PSPx layers, groups, and masks, and while I got the end result (no defringing), I am very unsure what layers did what and in what order they should be to match what you are doing. I wonder what PS users will come up with if they try to execute your tut within PS. I actually plan to try this within PS just "to see" what happens.

I am not sure how to ask for additional help, and will just keep trying various combinations of layer and group formation. More work on your part (for less gain) is to expand your tut to more clearly describe the (intermediate) steps. Your layer stack picture is also incomplete (cutoff in your capture) and, if the capture were expanded, might offer additional clues on what I need to have in mine.

This is clearly an "advanced technique", and beginners like myself probably have no right mucking around trying to make it work right now.

The attachment (my first) shows the end result and my layer stack (with a black background) but the hair is on a transparent bg, not a black bg. Also, I have a small spot of remaining blue in the lower center of the hair resulting (I think) from careless manual painting on the manual fix layer. As further demonstration of my need for additional learning, I am failing in trying to adjust the remaining blue out.

[Edit: I should mention that I started with a screen capture of the left side of your Figure 1 and did not do the Brown tutorial from scratch. Maybe that fact is contributing to my troubles here. (?)]

Thanks for sharing; super work!
Ken

PS: Anyone else trying this out???

[bart_hickman]

Hi Ken,

The reason you're not seeing the black background is the fringy object isn't contructed correctly. You have a raster layer called "Raster 3" where there should be a mask layer to remove the background (I called this Mask 1 in my tut).

That's a good idea to show the entire layer stackup. I'll put that in at the end of the tut.

Bart

[ajava]

Originally Posted by mistermonday

I simply converted the orig image to LAB and selected the B channel (most contrast) and duplicated it. Then using the Apply Image command, applied the B channel to itself in Overlay Mode. A simple levels adjust to boost the contrast and the mask was pretty well done. Like Ro, I painted away the blue in the edge hair. Regards, Murray

I get the concept of what's going on here...trying to create as much contrast as possible to allow for distinct black and white areas in the image, to then allow for easy masking. But once you have the great contrasting image, how do you actually make it a mask? I understand masks and how they work, I just really get tripped up when actually trying to create one from a selection. Bear with me here, I'm a newbie! Thanks!!!

[lkroll]

Used GIMP. Duplicate the layer many 4 or 5 times since you'll need them. I used the color picker and picked the blue color and created a fill layer. I set the resulting fill layer to Divide and set opacity to 50%. Merge down. Set the resulting layer to Dodge. Paint the obvious parts that suppose to be head/hair white. Desaturate this layer and do an autolevel. Do any necessary obvious b/w fills and cut the layer. Create a layer mask on one of the duplicate base layers and anchor the cut layer in place. Create a transparent layer on top and set to color. Use color picker to pick a good color from the hair and paint the edges (gets rid of the remaining blue). Merge Down. This step removes the mask and also creates the target so that you can copy a new background to it. Delete any remaining base layers. Takes a few minutes to understand this, but, in the end, you can do a mask for this in a matter of a couple of minutes. It heavily depended on the fact that you had a solid color background by the way. Here's the PSD file (transparency intact; used yousendit to host since the file is over 1Meg and I'm running out of storage space; would have saved it as PNG, but, for some reason transparency of PNG files saved with GIMP is not compatible with PS; a problem that will have to wait til later to figure out).

[Kraellin]

complex selections like this have always been a bit of a problem for me. i can normally get things fairly decent, but not exact. and i have gotten better, but i still need work.

i'm fairly happy with this technique, but it has limitations because i had to use some blending modes that may not always work on every image. they just happened to work with this one because of the contrasts and brightnesses.

i'm also not going to try to post the steps here as it got pretty convoluted and i'm not even quite sure all i did either. suffice it to say that i'm still trying to perfect a good working technique for all this. i did take some steps no one else has mentioned, though, and i'll give you what i can of those.

i can make a decent mask. that was fairly easy, so i'll skip that. the hard part of this image is that there is blue where you want transparent and there is blue where you dont want transparent. this makes things a bit tricky because if you simply erase the blue you also erase the blue where you dont want to. and if you alter the blue where you do want it to match up with the rest of the hair, you also alter the blue where you want it transparent and removed.

so, one of my steps was to use the 'color replacement' tool in psp 10. i replaced the blue with black where i wanted it transparent and then used a plugin to 'eliminate black'. that wiped out the blue where i wanted it transparent.

the other odd part i did was not to use a hue/sat layer, but instead used the 'colorize' tool. this allowed me to easily adjust hues from blues to reds while keeping the relative values of the blues over into the reds. it also allowed me to adjust the lightness of the current blues a bit also. this worked REALLY well on this particular image and was one of the last steps i did in getting the full hair-as-i-wanted-it image with the rest of the image as a transparency.

but all of the above needs a bit of work. it's a long process, somewhat inexact and i had to make one final step to bring in the rest of the fringe hair i had lost. i made a new, blank raster layer, put a gradient fill below it and then brought in the original image complete and unchanged and put that below the filled raster layer. i then set the fill layer to 'light' and that brought out the remaining lost fringe from the original.

like i say...i'm still evolving this process

craig

[Ken45140]

Craig: I am certainly a beginner on these more complex hair extractions. However, as the attachment shows, the BackGround Eraser in PSPx (which you say you use primarily) is more powerful than I had first realized. The following link is an indepth article by the developer of the BGE in which the details are explained. With that and some other help on the PSPx Corel Newsgroup, I was able to produce the extractions illustrated in the figure.

This is the source of the article:
http://tinyurl.com/8h2ck

BTW, the panel talking about the Brown Technique relates to somewhat modified steps to accomplish the same objective in PSPx rather than in PS.

Ken

[Edit: I need to rework the image to lower its size---see next reply.]

[Ken45140]

Image to go with previous post.

Ken

[bart_hickman]

That BGE is one of those little gems that doesn't get mentioned as much as it should.

Another object extraction method that I use when the background is extremely chaotic and variable, but the foreground object has reasonably sharp edges, is using the vector curve tool to draw a path around the object. You can carefully fine-tune the path, adding nodes or deleting nodes as needed to get a perfect fit. Then convert the path into a selection. This method is called for only in pretty small minority circumstances--the BGE deals with about ~80% of situations. Masking handles most of the rest.

I was going to mention that I often find it beneficial to run the noise removal tool on an image prior to erasing or masking--this smoothes out noise and/or jpeg artifacts that can cause splotchiness in edges.

Bart

[Ken45140]

Bart:

Chaos like in this image from another thread? Even the triple screen on the second version, which shows the hair a little more clearly, is still a bear to try and extract. I have tried all sorts of approaches (in PSPx and PS7) and have nothing to show for my 60+ cumulativer minutes working on it. I actually don't think it can be done because of the common color pixels all mixed in with the hair and the wall or vice versa. Esp in the lower right and lower left areas. I notice that no one here has tossed up an "extraction" solution for this one.

Ken

[bart_hickman]

That's a pretty pathological situation. I used my previous method--it's at it's limits. I had to apply a curve to the girl depending on the background to make her exposure appear to match. I also did some smudging on Mask 1 and 2 to smooth them out a bit as the original was noisy and artifacty.

Bart

[Ken45140]

Bart: You are the master! Do you mind showing me the settings on your Channel Mixer dialog boxes or just write them in text. I'm motivated to give it one more go since I see there is a light at the end of the tunnel. OTOH, maybe I need to practice on another 100 or so before coming back to this one.

Ken

[creeduk]

Talking of Russel Brown, check out his podcasts, he has a new one, extreme masking using multiple methods to really get the mask down!