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making alpha masks

making alpha masks

Postby pbacot » Fri May 18, 2012 9:38 pm

I have been wanting to make more of my own images for entourage lately. I have been winging it OK, but would like to see some tutorials on professional and efficient ways of making alpha channel masks and other methods in creating good entourage cutouts from photographic and other sources. Optimal sizes, color profiles etc.. How to do it quickly but good looking and functional for use in SU and other graphics. Any good sources?

Peter
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Re: making alpha masks

Postby Gaieus » Sat May 19, 2012 12:17 am

I am far from being good at it but when I encountered this tutorial, I found it very useful. Those ugly halos around cutouts can destroy all the illusion:
http://www.cgtextures.com/content.php?a ... me=alphabg

I have found that beside blurring, some glow on a secondary layer can also help tremendously.
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Re: making alpha masks

Postby PunchRender » Sat May 19, 2012 1:21 am

Start with objects on relatively clean backgrounds- no trees in the background. Objects for cutout should be around 800 pixels high. Start with an auto-color to get rid of any color casts, and avoid strong shadows if possible, as they are harder to blend into the final image.

At work, we usually do a quick selection tool to rough out the basics, and then refine edge, increasing smoothness, contrast, and shift edge to get the outline cleaner. It's important to overselect a little to avoid the background peaking through. If you're not using Photoshop, you can do a combination of shrink selection, smooth, and feather to get a similar effect.

The old school way to do it, which is slower and a little cleaner, is to outline with the pen tool, and then make selection with a feather of a half pixel. Also, our team at PunchRender just published a set of cutouts. Check out our other thread.
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Re: making alpha masks

Postby pbacot » Sat May 19, 2012 1:48 am

Thanks for the notes! I use GIMP (I meant to mention) at present but usually find PS tutorials are still helpful. I'll look into these ideas.
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Re: making alpha masks

Postby Howard Leslie » Sun May 20, 2012 9:11 am

Peter,
See this Tutorial here - some of the techniques used may be useful for your purposes:
http://forums.sketchucation.com/viewtopic.php?f=18&t=6819
It shows a quick way to cut around objects in Photoshop etc
.......
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Re: making alpha masks

Postby pbacot » Sun May 20, 2012 6:04 pm

Hi Leslie,

Thanks for the link! I am going through the tutorial.

later:

For those using that tutorial, the GML Matting plug-in has been discontinued. You can go to the Graphics Media Lab site and try their current "Cut-out" but the old GML Matting plugin is available here: http://www.photo-freeware.net/gml-matting.php

Since I have a Mac, I don't think I can use it myself--or vouch for the script DL. So that tutorial requires having the script, which is for windows.

Actually I might need some more basic explanations on terms and processes.

Peter

here's what I do just making up my own methods--but it takes a long time:
Oak tree.png


Small test render in SU Maxwell

oak su max.png
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Re: making alpha masks

Postby marked001 » Tue May 22, 2012 9:10 pm

I haven't yet had a chance to watch it.. but I just noticed a tutorial on this the other day: http://www.pixelflakes.com/tutorial/11-people-cutouts/

Their other tutorials are really great, so I'm expecting this to be no different.
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Re: making alpha masks

Postby pbacot » Wed May 23, 2012 4:21 pm

Jason,

That looks good. Thank you. Realizing that the "pro" way to approach this is hard (or tedious) work plus plugins. But not so time consuming once you learn the techniques.

Peter
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