Home ›

More Background Manipulation with the GIMP

Apr 06, 2010  By Mitch Frazier
 in
FAIL (the browser should render some flash content, not this).

Comments

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

Foreground Select

Deus Nefum's picture
Submitted by Deus Nefum (not verified) on Tue, 04/27/2010 - 13:08.

Why not just use the foreground select tool?

http://video.google.com/videoplay?docid=2540655610648907719#

Quick Mask Tip

MacAnthony's picture
Submitted by MacAnthony (not verified) on Wed, 04/07/2010 - 11:06.

When you are in quick mask mode, you don't have to change to the erase tool to remove the mask. If you look at an alpha channel mask, you see that the mask is black and the unmasked area is white. You can just keep using the pen tool but switch the foreground and background color between black and white to add/remove the mask. Black with "paint" more mask and white will erase the mask.

Thanks

Mitch Frazier's picture
Submitted by Mitch Frazier on Wed, 04/07/2010 - 11:14.

I noticed something "strange" happening when I was doing one of my video "takes" and I had the foreground/background colors swapped, but... I didn't take time to figure it out.

So thanks for the tip, I only hope I'll remember it the next time I need it :).

Mitch Frazier is an Associate Editor for Linux Journal.

A more appropriate way to

cbleslie's picture
Submitted by cbleslie (not verified) on Wed, 04/07/2010 - 08:57.

A more appropriate way to accomplish the action of extracting "Chilli Dog" from his/her background would to have been to use a Layer Mask, thus making the editing "non-destructive" should you ever have to go back and fix a transparency mistake 7 hours down the road into a project.

Layer Mask

Mitch Frazier's picture
Submitted by Mitch Frazier on Wed, 04/07/2010 - 10:57.

As I've stated before: I'm no gimp expert, or for that matter an expert in any sort of photo manipulation program. So tips are always welcome and if you'd like to contribute a video of your own let me know.

Mitch Frazier is an Associate Editor for Linux Journal.

I just may.... :)

cbleslie's picture
Submitted by cbleslie (not verified) on Wed, 04/07/2010 - 11:03.

I just may.... :)

Please do

Mitch Frazier's picture
Submitted by Mitch Frazier on Wed, 04/07/2010 - 11:06.

We're always looking for contributors, particularly for videos.

Mitch Frazier is an Associate Editor for Linux Journal.

feather and transparent

lefty.crupps's picture
Submitted by lefty.crupps (not verified) on Wed, 04/07/2010 - 08:07.

I find it better to use some 'feathering' when selecting these types of images, to help soften the edges of the subject (chilli dog in this example). Then when removing the background, the subject has softer edges.

If you then save the image with a transparent background (png files have this, gimp files have it, but jpegs do not), you don't have any of the slightly-blue borders.

Nice tutorial, that QuickMask button is new to me!

More Info Please

Mitch Frazier's picture
Submitted by Mitch Frazier on Wed, 04/07/2010 - 11:19.

I know in theory what you're referring to and I think I've accidentally stumbled across it when cutting out images, but I've never been able to figure out exactly how I got there. So a bit more info on how to do this would be nice.

Mitch Frazier is an Associate Editor for Linux Journal.

Feathered edges

lefty.crupps's picture
Submitted by lefty.crupps (not verified) on Wed, 04/07/2010 - 11:45.

> So a bit more info on how to do this would be nice.

In the Gimp, once you've chosen a Selection tool (such as the Lasso/Free Select that you picked), the bottom half of the toolbox changes to that tool's options.

Click the box []Feathered Edges and then you can adjust its radius, which is basically the distance from your line that will become slowly faded from fully opaque to fully transparent. This will help the image appear to blend in better with the background. I do not know how this works in conjunction with the Quick Mask thing, that should be tested a bit.

Note, if you then paste this onto a blue background (or whatever) for later use as you suggested, your fade will have some blue in it which pretty much ruins the effect. Much better to then save it as a file format that allows transparency (such as PNG), and just keep the background empty (transparent).

.

Cycron's picture
Submitted by Cycron (not verified) on Tue, 04/06/2010 - 15:43.

Yes, you could have done color select, you just hold down shift when you're doing it so you can select more than one color. And I would have changes the lighting a bit in the photo so the dog would fit in with the rest of the photo. and I would have had the background color as transparent, not blue, because if its blue then (as you can see) there is a little blue lining around the dog when you paste him in.

Thanks

Mitch Frazier's picture
Submitted by Mitch Frazier on Wed, 04/07/2010 - 11:01.

That's a good point. I have a bit of a phobia about "transparency" I think. Every time I have an image with transparency something seems to not work like I think it should. But, remember I'm no gimp expert so I'm 100% sure it's just my lack of knowledge about the gimp that is causing me problems.

Mitch Frazier is an Associate Editor for Linux Journal.

Very funny!

Mauricio.Mora's picture
Submitted by Mauricio.Mora (not verified) on Tue, 04/06/2010 - 15:20.

Thanks Mitch!
Very funny and basic for Gimp, right?

Basic Once You Know It

Mitch Frazier's picture
Submitted by Mitch Frazier on Wed, 04/07/2010 - 11:10.

It's fairly basic stuff I guess but if you're new to the gimp or only use it occasionally some of these things are far from obvious. I'm an occasional gimp user and I've only recently discovered these "basic" things.

Mitch Frazier is an Associate Editor for Linux Journal.

Webcast
More Resources
How to Build an Optimal Hadoop Cluster to Store and Maintain Unlimited Amounts of Data Using Microservers

Realizing the promise of Apache® Hadoop® requires the effective deployment of compute, memory, storage and networking to achieve optimal results. With its flexibility and multitude of options, it is easy to over or under provision the server infrastructure, resulting in poor performance and high TCO. Join us for an in depth, technical discussion with industry experts from leading Hadoop and server companies who will provide insights into the key considerations for designing and deploying an optimal Hadoop cluster.

Learn More

Sponsored by AMD

White Paper
More Resources
Red Hat White Paper: Using an Open Source Framework to Catch the Bad Guy

Built-in forensics, incident response, and security with Red Hat Enterprise Linux 6

Every security policy provides guidance and requirements for ensuring adequate protection of information and data, as well as high-level technical and administrative security requirements for a system in a given environment. Traditionally, providing security for a system focuses on the confidentiality of the information on it. However, protecting the data integrity and system and data availability is just as important. For example, when processing United States intelligence information, there are three attributes that require protection: confidentiality, integrity, and availability.

Learn more about catching the bad guy in this free white paper.

Learn More

Sponsored by DLT Solutions