How to distinguish the objects and background?

wbloodc · Post by **wbloodc** » Thu Apr 01, 2010 7:13 am

Hi, guys:
I'm doing image processing for an shopping website nowadays. I have to process about 1500 to 2000 pictures everyday. That's really a boring work and takes lots of times. I can't stand it no more.

As the processing procedure of every picture is the same, so I'm now trying to use script to let it works automatically.

Now I've faced a big problem: how to distinguish the objects from the background? I used to do it with magic wand tool and ploygonal lasso tool by hand. I've tried to call an action that record Magic Wand Tool, but it not works not very well. Neither lose details nor choose too many backgrounds.

I also thinks about to transform the picture into bit code, and analysing the RGB value of each pixel. But to accomplish this needs more knowledges about Computer Graphics, which is too hard to me. Besides, this processing may costs too much time and needs a good computer.

Does anyone knows how to solve this problem? Please give me some advise, thanks a lot!

Hi, Mike, do you have an idea about this issue? I need you help!

kpt · Post by **kpt** » Thu Apr 01, 2010 12:24 pm

Could you use Chroma key as a background instead? There is at least one plugin for Photoshop that should (haven't used it myself) let you get rid of the background easily that way.

Mike Hale · Post by **Mike Hale** » Thu Apr 01, 2010 2:04 pm

I have tried several time to come up with a 'background removal' script. I have never had much luck either.

If it can be done with javascript, it's beyond my skill level.

xbytor · Post by **xbytor** » Thu Apr 01, 2010 2:54 pm

Chromakey is the way to go. Ive got a cheap green screen that I've used a couple of times that made things much easier. There's at least one website that has screens of different colors depending on your content along with other useful info.

If you're not using Chromakey of some kind, the Quick Selection tool is what I use most often.

-X

Patrick · Post by **Patrick** » Thu Apr 01, 2010 3:56 pm

These are links i have from a few years ago when I was looking into chroma key, they may help.

http://www.seanet.com/~bradford/blue_gr ... cts_1.html ... cts_1.html
http://www.chroma-key.com/chroma_key_special.html
http://fors.net/chromoholics/
http://www.digitalanarchy.com/primatte/chromakey.html

Mike Hale · Post by **Mike Hale** » Thu Apr 01, 2010 4:29 pm

Chromakey is great if you have control over how the images are taken and the only purpose for the images is to be shown without a background or different background.

My guess is if he is doing 1000s of image a day they are coming from several sources.

wbloodc · Post by **wbloodc** » Fri Apr 02, 2010 3:37 am

Thanks a lot for your guys reply.

I've done some research on the chroma key you mentioned, I'm afraid it could not help me as the chroma key requires blue/green background, while mine pictures' background is black/white.

The pictures I'm deal with is like coats, trousers, T-shirts, watches, necklaces, bags etc. The object is taken with black/white background, I have to distinguish the object and the background, then fill the background black/white.

The most time-consuming work is to set apart the object and the background, that's why I wanna to script it.

xbytor · Post by **xbytor** » Fri Apr 02, 2010 4:31 am

How do you do it now? Magic Wand can go a long way in an automated solution, but it's not perfect by any means.

wbloodc · Post by **wbloodc** » Fri Apr 02, 2010 4:38 am

I use ploygonal lasso tool to select the detail part, but that's really boring. You can imagine a silver or a pearl necklace put in the white background, I have to use the ploygonal lasso to choose every single pearl which makes me crazy!!!

I really don't wanna do it by hand any more.

kpt · Post by **kpt** » Fri Apr 02, 2010 8:57 am

Have you tried using the Dodge tool set to Highlights and about 10% to make the almost-white background pure white?