Preserved Topic: extract (Page 1 of 1)

does anyone have any tips on using the extract tool? i am having trouble coming up with good edge definition.

played with it a few times, but soon realized its a bit of a 'cowboys' tool. No offense intended, but unless your edges are really well defined between the object you want to 'extract' ('isolate') from your background, then unless you have spent an incredulous amount of time practicing with the 'extract' tool, you will bein for a hard time.

Personally speaking I would choose the 'path' tool with a combination of an alpha channel everytime.

Lets presume you dont want to get to deep into this though....

Play with the settings within the extract tool options... try differnt width brush sizes, etc... each image is going to be different, so the more you practice, the more you willget a 'feel' for the tool....

at the end of the day. separating an objct from its background is usually not an easy task. The better the contrast between the objects edges and its background, the better the 'extract' tool will be me thinks. If all else fails, there are other ways to separate, but those ways need time invested in learning other tools within PS

Sorry not to provide an easy answer .. good luck

EDIT: cant believe I am encouraging you, but , I did I quickie search and came up with this link.. http://graphicdesign.about.com/arts/graphicdesign/library/tutorials/photoshop/blextracta.htm

its four pages worth! enjoy~



[This message has been edited by vogonpoet (edited 02-18-2001).]

We have an ongoing gig at work shooting shoes for a dot com. All have to be on a pure white background with a drop shadow. We shoot on white, but there's still always tone, so silhouetting is not avoidable. Black shoes are easy - often a curve will do the trick. Light shoes, white shoes are a different matter. We have to decide on the fly what's going to be the fastest/easiest (we ain't getting paid much per shot, so have to be brutaly efficient!). Sometimes it's the pen tool; sometimes it's quick pass of the dodge (set to highlights) tool, and follow up with the lasso. Sometimes it's extract. Rarely does extract work perfectly, especially down along the existing shadow by the sole, or up at the top of a white shoe where it doesn't differ too much from the background. Our solution sounds clunky, but it works okay. (This work around is necessary because extract DELETES the background. Ah, if only it created a layer mask....)

Copy the existing background twice, so you have three identical layers total. Fill the background layer with white. Add a layer mask to the middle layer, hiding all. Run extract on the top, getting it as good as possible. Then go to the middle layer and paint in white on the layer mask to bring back the parts the extract tool ate into. Sometimes a bit of eraser is necessary on the top wlayer too. Finally, we paint the drop shadow with the airbrush tool on the background layer. A lot of work? Yep. But there are instances where, if you can believe it, this is the fastest way. Good luck. It's actually a pretty cool tool but as VP stated it's happier when there is distinct color or tonal contrast.

On the rare occassion that I use Extract, I load the selection, toss it into an Alpha (just in case), trash the Extracted Layer, copy the photo and use the Alpha for a Layer Mask. Fairly easy to do with a few choice, home-brew Actions to do the grunt-work. Somewhere in there I toss in an extra Layer for use as a background. Touch-up as necessary.

Hey, VP, I got too involved fixing problems with Burst of Light to give you a status report on Extracting from Background. I'm finally starting to feel more comfortable tackling such a subject. It's getting there, but Burst of Light comes first.

For whispies, get to know Curves and Colour Replacer. Those are my two main weapons. No particular order or set formula. I should mention that I use a lot of Zen as well.

Three! Three main weapons for whispies: One, Curves; Two, Colour Replacer; and, Three, Zen. Those are my three main weapons against whispies!

Channel Mixer comes in handy as well -- Four! Four main weapons against whispies!

Yeah, and I've got a bag of Alpha tricks just waiting to be unleashed. Mainly artifact hunting and stitching. Maybe a few others that I can't think of right now.

Pretty much anything in the Image > Adjust family can come in handy. Sad thing is, I can't imagine anybody being intimately familiar with *all* of them. Familiar with all of them and intimate with a few, but not intimate with all of them. Maybe Steve will prove me wrong on that one. Nothing like brain-fry for making silly assertions.

Steve, from you describe for the shoes, sounds like a job for that Magic Colour Area Select thingamabob. Not sure what you mean about the drop shadow. Is it a part of the picture to begin with, extracted out, then re-brushed in? Or is the drop shadow non-existant until you brush it in?

warjournal:
Yeah. We bottom light the plexi table, but there's always a wimpy little shadow there to begin with which complicates things. We've gotta get rid of reality and brush in artificiality which ends up looking more like what people accept as reality than reality itself does.
Did I just type that?

And the color-based selection tools don't help, because the problem areas are all too close in color. Picture trying to catch and edge between a black sole, it's shadow and a white surface. It's all shades of gray. Picture a white wedding shoe, it's shadow and a white background. Magnetic pen tool can't find the edge reliably, nor can magnetic lasso, nor can background eraser. It's hand work.

I'd like to say this is what separates the men from the boys, but the real story has more to do with what you do because you get paid to do it. Do it enough times, you get faster at seeing what needs to be done and then doing it. No way to make it less miserable though.

Why not pick a really offensive background color. Wouldn't that make the extraction gig a lot easier?

-mage-

too much chance of that color contaminating the product.

Good thought though.

As long as there aren't too many sharp inside corners and whispies aren't a consideration, I'll take a hand-job any day. Even though I don't get paid for it, that's how I've been doing it for years. But there is something to be said for a quick Curves adjustment.

Should have known Steve would be the man and already have all the options weighed. My brain wasn't exactly up to snuff yesterday. I was up and running for 20+ hours. I don't plan on pulling a haul like that for some time.

Speaking of reality, I read an article a few years ago about faking it. There is something rather specific (can't remember what, though) that is always faked. When the real deal is used, people reject it because they are so used to the fake.