Taming the Wild Selection

October 17, 2000

Practice the technique of making and modifying selections in PSP6
using the rectangular and freehand selection tools in part 1.
In part 2, practice adding to and subtracting from an existing selection.

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[ Part 2 ]

Several folks mentioned having trouble making good selections, so today we will focus on a few techniques to help you create accurate and useful selections without many redos.

Like all sports, the sport of selecting gets better with practice. The more you make, the better you get. However, there are some tricks that might help you out.

One thing that confuses the heck out of folks is whether to antialias or feather the selection. Or when to do either of those. We will cover this first.

Let's start with the simplest selection tool, the Rectangular Selection Tool to help us visualize the options when making a selection.

In PSP, open the photo, GreenBldg.jpg.

Either click the image on the left to open the 800 X 600 version of this image, or use the link above. Right click on that image and Save Image to your harddrive. Please don't try to use the small image on the left to do this tutorial.

Pick the Rectangular Selection tool on PSP's Tool Palette.


On the Tool Options Palette, toggled on with the "o" key on the keyboard, set the Feather to 0 and UNcheck antialias.

Click and drag a selection in the green brick.

Release the mouse button to set the selection and start up the marching ants marquee.

Hit the Copy button on the Tool Bar, then RIGHT click on the image's title bar picking paste as a new layer from the flyout box.

Drag the layer to the blue sky area. Remove the selection from the background, Selection/Select None from the Menu bar or Ctrl +D on the keyboard.

Pick the rectangular selection tool again but this time, CHECK the antialias button on the Tool Palette.
Make sure to highlight the background layer on the Layers Palette ( toggled on with the L key on the keyboard). Drag a selection in about the same area as before, then repeat the copy and paste as new layer and drag to an open area of the sky.

Repeat this process one more time leaving antialias Checked but moving the feather up to 5.

(Make sure you choose the background layer before copying the selection or you will end up with a blank layer when you paste.)

With all 3 layers sitting up on the blue sky, be the judge of the differences between them.

Use the Zoom tool, click once in the image and scroll to see the 3 layers in the sky.

Notice on Layer 1, above without any feather or antialiasing, how the edges are very crisp and clear and not blended in at all with the background.

Notice on Layer 2, with the antialiasing only, how the edges are slightly softer, on the first pixels around the edge.

Notice on Layer 3, how the edge pixels are varying in transparency from totally clear to opaque in the ten pixels we feathered.

On the Layer palette, turn off the background layer by clicking the glasses icon next to the layer name, for a clearer view of the edge varying transparency for the 3 samples.

So when would you use these variations?

Personally, I make my selections unfeathered 90 percent of the time. I use antialias to barely blend the pasted part into the underlying layer. Almost always use Antilalias with point to point and freehand selections.

I use the hard edged options, no feather no antialias, when I plan to reduce the colors to 256 or less for a GIF image and need a crisp division between objects in the image.

Once a selection is on, it can be modified. But let's get into in a bit :)

I suspect most of you struggle most with the freehand selection tools to select part of an image. Let's go there.

Pick the Lasso, the freehand selection tool, from the Tool Palette.

Make sure the background layer is selected to work on.

 

I think the Point to Point Option offers the most control of all the three Selection type options on the Tool Options palette so let's use it to demonstrate with.

Set the feather to 0 and check antialias.

Our goal is to select and make an object out of the first green door on the left. It's an easy one to start with.

Here is a clue. Zoom into the area you want to select. On this image I found 4:1 Zoom just about right. Please note the screen captures below are zoomed in!

Start by clicking at the top left corner of the white door frame.

Since we want a pretty smooth line across the top, click again about where the door top ornament joins the top white board.

To gather in the ornament, click several point around the outside of it just where the green of the wall meets the different colored pixels.

On a complicated object, it might take 10 clicks of setting points around the curve to end up with a clean smooth curve.

For the rest of the top of the door, one click on the right top corner where the white meets the wall green is about right.

Then one click down the edge, one click back to the left under the top door plate.

One click should take you all the way down the right side to the bottom corner.

One click across the sill plate to the bottom left corner, one click up to the top.

One left to the top plates bottom left corner and one to finish up.

Finish where you started and rightclick or double click to set the selection.

With antialias on, the selection will jump outwards just a bit.

Now for the acid test. Using the copy icon and copy the selection to the clipboard.

Zoom out by right clicking with the Zoom tool on photo until its back to 1:1.

Right click on the title bar and Paste as a new layer. Drag the door layer around on the image and it should blend in cleanly where ever you place it, especially in a colored area similar to the background from which you copied it.

Things to bear in mind with making freehand selections.

1. Use several clicks to make a smooth curve.
2. Use as few clicks as possible to outline a straight edge, the antialias will help you out here.
3. Be careful using feather when making a selection. I suggest trying to avoid it. Feathering can be better controlled after the selection is made.
4. Be prepared to practice a lot. Its the surest way to get better.
5. Zoom in close to that which you are trying to select. Better for your selection technique and accuracy and much better for your eyes!!!

Other tricks: Selection Modification

With the selection still on the door area, select the background layer again. Let's say too much of the green background is still in the selection and we want to tighten up the selection and get rid of another few edge pixels.

Go to Selection/Modify/ Contract... Set the value to 2 on the dialog box.

Press OK.

Notice in the image how the selection moves in 2 pixels all the way around the selected area.

If your test one looks like my sample, some of the white area is now outside the selection.

Let's soften that.

Go to Selections/Modify/
Feather on the Menu Bar. Enter 2 pixels there and OK.

Copy this selection to the clipboard and paste as a new layer as before.

Notice how much softer the edges are in the new layer. Pull both the door layers up into the blue sky. There probably will be a harsher contrast between door number 1 just with the antialias and the sky and door number 2, with the feather.

Here is a circumstance you would feather the selection.

If you planned on placing it again a background either much lighter or much darker than the original.

Feathered selections make for a cleaner transition!

But see how much better door number 1 looks against the green background compared to door number 2!

Another thing, you can paste the selected and copied object as a new image onto a transparent background and save it as a psp file for later use. I call those Object files. :)

~~~~~~~~End of Part 1~~~~~~~~

Please use this link for Part 2.

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