[Courses][gimp] Lesson 7: Selecting Complex Shapes
Julie Sloan
juliesloan at mindspring.com
Mon Mar 14 09:48:58 EST 2005
On Friday 11 March 2005 10:50 pm, Akkana Peck wrote:
> In Lesson 4, we used some simple basic tools to select part of an
> image. In this lesson, I'll cover selection of complex shapes.
> GENERAL ADVICE
>
> When selecting images out of an image, there are two important tricks:
> (1) Zoom the image as much as you can, so you can see what you're
> doing, and (2) Turn on "feathering".
Zoom is my friend. In gimp1.2.5 I use the [+ - 1] keys and do not need
CTRL with them. I also think [view > new view] is indispensable when
editing a zoomed image.
> That's where Bezier Paths come in! The Bezier (pronounced
> "bez-ee-ay")
I think of it as "BEE zjer." I will try to fix this mindset :)
> Time to start! Click-and-release the mouse button wherever you want
> to start your selection.
I began with a sunflower:
http://juliesloan.home.mindspring.com/gimp/sunflower.jpg
Here is a screenshot of my initial selection:
http://juliesloan.home.mindspring.com/gimp/snapshot1.jpg
> What if you click in the wrong place?
> In gimp 1, ctrl-click seems to move the current point.
This takes some practice.
As does making additional paths after the first one; It took me a while to
figure out had to click "new path" in the paths dialogue BEFORE I start
selecting.
> Gimp 1.2 has a Feathering checkbox in the Bezier Selection Tool
> Options dialog, like most selection tools.
FWIW I turned on feathering in Bezier select, but when I closed the gimp
and reopened it, it had reverted to the non-feathering default.
> You've made your selection. What can you do with it?
>
> Of course, you can copy, then paste into another image
I did that:
http://juliesloan.home.mindspring.com/gimp/onwhite.jpg
but then I noticed I needed to take more background out, among the leaves :(
so I did:
http://juliesloan.home.mindspring.com/gimp/onwhite2.jpg
but this doesn't help if I want to blur or otherwise enhance (dehance?) the
background, so I went back to my xcf and made more BEEzjer - I mean
bez-ee-YAY selections
and once I decided how I was going to change the bg made a note of the
values and applied them to each selection, one at a time:
using colors > curves to lighten and darken, and gaussian blur RLE:
http://juliesloan.home.mindspring.com/gimp/sunflower-light.jpg
http://juliesloan.home.mindspring.com/gimp/sunflower-dark.jpg
http://juliesloan.home.mindspring.com/gimp/sunflower-blur.jpg
[filters >noise > hurl] makes an interesting effect too :)
I ended up with a favorite, /weird.jpg, which would have looked better with
a fine edge selected instead of feathered, but still think it's cool.
Julie
> Homework: Select a complex shape from an image, using path or
> intelligent scissors, and apply any gimp filter (or combination of
> filters) to either the shape or its background. Or, if you prefer,
> just paste the shape into another image.
>
> Next lesson: How to get really cool looking text.
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