best tool for separating (cropping) figure from background?

[urlwolf]

The scenario:
typical photo of a person against the background.
I'm interested in separating (cropping) figure from background, in an automatic (or semi-automatic) way. If possible, I'd like a program that could do this in batch mode.

Is there such a thing? I tried Xara extreme, but it seems you have to draw the boundaries yourself...
Thanks a lot

[nudone]

can't say i've heard of anything that will do it in batch mode, or even in a completely automatic way.

really depends on how great the contrast is between the background and the object to separate and how 'clean' you want the separation.

requires manual input i'd say.

[Perry Mowbray]

I don't think you're going to be able to find something that doesn't need some sort of input.

You can have a look at http://grail.cs.washington.edu/projects/photomontage/, it's input is quite revolutionary (though I had crash issues on my machine).

- Perry

[elpresi]

There is an interesting free PS plugin:
http://graphics.cs.msu.su/en/research/Segment/index.html
http://research.graphicon.ru/growcut/gml-growcut.html

[Ampa]

It is really going to depend upon the background... The film industry use green screen (or historically bluescreen) to matte actors out of one environment and into another.

If your background is complex and non uniform then you will need to do the process by hand.

If your background is simple and uniform in colour then you will be able to automate to a greater or lesser degree.

There are many tools that will help you, but the reason that there are so many is because this is a nontrivial task, and different scenarios require different solutions.

Here are a few starters...

Most of matting will be done in an application like Photoshop as these are raster / pixel based techniques that rely on differences in hue / brightness to detect edges.  Occasionally there is no choice but to cutout mattes by hand, in which case a vector solution can be used (perhaps with a tool such as Xara Xtreme).

Photoshop has many tools that help automate the matte proceedure - the Magic Wand Tool is particularly quick, and works well in simple cases.

[Carol Haynes]

Corel Knockout 2 does this (it is what it is designed for) but it does require user input. You basically draw a thickish stroke around the area to knowckout and then it sorts out the actual edges within that stroke band area.

Having said that I think it is quite expensive for what it does, and like all other systems not perfect. It also has the disadvantage that development appears to have stopped now for a number of years. (I have had it for at least 3 years and there have been no new updates or bugfixes in that time).

See http://www.corel.com/servlet/Satellite?pagename=Corel3/Products/Display&pfid=1047024307431&pid=1047022702205 for details.

Another app you may want to consider is Adobe Illustrator which has built in automatic tracing. This is really designed to convert photos to illustartion type images but it does it by making ares of the image into selections. There is a trial version so you can see if it does what you want (but it is obviously an expensive app).

[urlwolf]

Wow, Thanks a lot for all the answers.
I knew about adobe PS  Magic Wand Tool, I think I have used it in the past.
I uspected that this would be a non-trivial, non-automatizable process . And yes, the pics I had in mind do have complex backgrounds. I guess it'd be easier to get a bunch of face pictures that are either already cropped or on a neutral, homogeneous background.

Thanks a lot again!

[Carol Haynes]

As well as the magic wand tool PS also has an 'extract' tool - which is designed to make this relatively simple. The results really depend on how complex the join is between the foreground and background and how much time you are prepared to spend fine tuning your selection. Basically you mask the edge of the bit you want to cut out and then fill the remaining area to keep with the fill tool, hit extract and it does the rest. It works best where there is a big contrast between the areas.

It is in the Filters menu ... here is the dialogue:



as a comparison here is Corel Knockout 2:



Knockout has a lot more flexibility and is quicker to use, but neither method can be described as quick methods.

I can't really see how you could expect any sort of automatic batch method unless you just wanted to extract exactly the same area or it is a single block of colour. How would the software know what you want?

[app103]

Newer versions of Paintshop Pro (v8+) have a background eraser tool that can make it much easier to cut out what you want from the background.

You can change the background to another color first, then select the background with the magic wand, then invert selection, then crop or whatever.

If you like the results and can figure out a way to get consistent results with it, you can create a python script to automate it and run it from within PSP.

I would give you screenshots of it in action but my trial of PSP 9 expired a long time ago.

[Perry Mowbray]

I use PhotoImpact which is a PS-like product, but at a much cheaper price. It's one of the best value of these types of apps IMO, though certainly not the best either.

[tsaint]

I use PhotoImpact which is a PS-like product, but at a much cheaper price. It's one of the best value of these types of apps IMO, though certainly not the best either.

Thought I'd download and try photoimpact on the strength of that. Unfortunately, when I tried to run the demo version I got a really curious message:
"limit users can not try this product. You can use normally after successful activation"

A bit freaky too, because my last post was in connection with limits of a function. (maths is an attitude"

[mouser]

i guess they are saying you have to be an administrator to install the program and run it for the first time, after which is should work for any user account?

[tsaint]

that would be fine, except I have admin privs.
I'll try actually being admin next/later.

[Perry Mowbray]

Thought I'd download and try photoimpact on the strength of that. Unfortunately, when I tried to run the demo version I got a really curious message:
"limit users can not try this product. You can use normally after successful activation"

Odd! Although the same problem (although with a different ULEAD product) was reported here. I don't know if that helps or is the same situation as yourself?

- Perry

[tsaint]

Thought I'd download and try photoimpact on the strength of that. Unfortunately, when I tried to run the demo version I got a really curious message:
"limit users can not try this product. You can use normally after successful activation"

Odd! Although the same problem (although with a different ULEAD product) was reported here. I don't know if that helps or is the same situation as yourself?

- Perry

yair, I saw that plus a couple of other references, but none had an answer unfortunately.
tony

[Perry Mowbray]

yair, I saw that plus a couple of other references, but none had an answer unfortunately.

...and I'm guessing you haven't played with it before... most odd! Pity really: it's a bit querky (interface wise) but the value for money can't be disputed. I'm not sure that I love it, but it's done the job for me for many years now.

- Perry

[tsaint]

...and I'm guessing you haven't played with it before...

or since! I installed the demo and that was that... locked out.