1.
Computer Science 2

2.
Basic Concepts in Photo Editing
• Edit images using selection in Adobe Photoshop

3.
Edit images using selection in Adobe Photoshop
❖ Demonstrate the following skills in selection
⮚ Selecting Basics
⮚ Selecting by Shape
⮚ Selecting by Color
⮚ Selecting Irregular Areas
⮚ Modifying Selections

4.
Lesson 3
Selecting Basics
A selection isolates part of an image so you can work on that
area without affecting the rest of the image.

5.
To make a selection and adjust only
the selected area
1. In the Tools panel, select the
Rectangular Marquee tool. Drag a
rectangular selection onto the image. The
area inside the animated border
represents your selection.
2. To select more, click the Add to
selection icon in the options bar or press
Shift and drag. To select less, click the
Subtract from selection icon in the
options bar or press Alt (Windows) or
Option (macOS) and drag.

6.
To make a selection and adjust only the
selected area
3. Select a layer you want to adjust. Then
try applying some adjustments (Image >
Adjustments). With a selection active,
adjustments affect only the selected area
of that layer. The same is true if you were
to apply a filter, paint, fill, copy, or make
other edits.
4. When you’re done, deselect by
choosing Select > Deselect or pressing
Control+D (Windows) or Command+D
(macOS).

7.
Selecting by Color
Adobe Photoshop provides us with
several ways to make selections by color.
Let's take an in-depth look at three
methods: the Eyedropper Tool, Color
Range and the Magic Wand Tool, as well
as how to fine-tune and modify color
selections.

8.
The Eyedropper Tool
The Eyedropper Tool is useful for selecting a single color
from an image and copying it in the Foreground Color
swatch. To select a color in an image, click the
Eyedropper Tool or the Foreground Color swatch in the
Toolbox and then click on the image.
Getting the exact color, you want may be difficult in high-
definition images, because the individual pixels are often
different shades. To get a precise selection, use the
Eyedropper Tool rather than the Foreground Color
swatch and then click the Show Sampling Ring check box
in the Options bar. When you press the mouse button,
the ring around the cursor shows you the color that will be
selected when you release the mouse.

9.
Color Range
When you want to select all of the pixels of a
specific color in an image, use Color Range,
available under the Select menu. When the
Color Range window is open and you hover the
cursor over the image, the cursor changes to the
Eyedropper Tool. Click a color and then adjust
the Fuzziness slider to specify the selection's
tolerance. Whichever colors are selected appear
in the preview window.
To add or remove colors from your selection.,
use the + and - Eyedroppers on the right of the
Color Range window. The Localized Color
Cluster and Detect Faces option are both good
for getting all of the similar pixels in one area.

10.
Magic Wand Tool
Using the Magic Wand Tool is the best way to make
color selections in specific parts of an image, rather
than the entire canvas. It's also good for cleaning up
a selection you already made with Color Range.
The Magic Wand Tool is in the Toolbox. If you don't
see it, hold the Quick Selection Tool to make the
Magic Wand Tool visible. Select Point Sample from
the Option bar's Sample Size menu. Click or drag
the tool over the color you want. Increase the
Tolerance in the Options bar if it's not selecting
enough colors in its range. Decrease the Tolerance if
it's selecting too many similar colors.

11.
Magic Wand Tool
On the left side of the Options bar, you'll
see four square icons.
Use these to:
- make a single selection,
- add to a selection
- subtract from a selection
- intersect with a selection

12.
Selecting Irregular Areas
As you might imagine, areas that aren’t uniform in
shape or color can be a real bear to select.
Luckily, Photoshop has a few tools in its arsenal
to help you get the job done. In this section, you’ll
learn about the three lassos and the Pen tool, as
well as a few ways to use these tools together to
select hard-to-grab spots.

13.
The Lasso Tools
The lasso toolset contains three freeform tools
that let you draw an outline around the area you
want to select. If you’ve got an amazingly steady
mouse hand or if you use a digital drawing tablet
(see the box on The Joy of Painter), you may fall
in love with the plain ol’ Lasso tool. If you’re trying
to select an object with a lot of straight edges, the
Polygonal Lasso tool will do you proud. And the
Magnetic Lasso tries to create a selection for you
by examining the color of the pixels your cursor is
over. This section explains all three tools, which
share a slot near the top of the Tools panel.

14.
The Lasso Tools
The regular Lasso tool lets you draw a selection
completely freeform as if you were drawing with a
pencil. To activate this tool, simply click it in the
Tools panel (its icon looks like a tiny lasso—no
surprise there) or press the L key. Then click in
your document and drag to create a selection.
When you release the mouse button, Photoshop
completes the selection with a straight line (that is,
if you don’t complete it yourself by mousing back
over your starting point) and you see marching
ants.

15.
Polygonal Lasso Tool
If your image has a lot of straight lines in it, the
Polygonal Lasso tool is your ticket. Instead of
letting you draw a selection that’s any shape at all,
the Polygonal Lasso draws only straight lines. It’s
super simple to use: click once to set the starting
point, move your cursor along the shape of the
item you want to select, and then click again
where the angle changes; repeat this process until
you’ve outlined the whole shape. To complete the
selection, point your cursor at the first point you
created. When a tiny circle appears below the
cursor (it looks like a degree symbol), click once
to close the selection and summon the marching
ants.

16.
Magnetic Lasso Tool
This tool has all the power of the other lasso tools,
except that it’s smart—or at least it tries to be! Click
once to set a starting point, and the Magnetic Lasso
tries to guess what you want to select by examining the
colors of the pixels your cursor is over (you don’t even
need to hold your mouse button down). As you move
your cursor over the edges you want to select, it sets
additional anchor points (fastening points that latch onto
the path you’re tracing; they look like tiny, see-through
squares). To close the selection, put the cursor over
your starting point. When a tiny circle appears below
the cursor, click once to close the selection and
summon the marching ants (or triple-click to close the
selection with a straight line).

17.
Modifying Selections
Move a selection border
Moving a selection border repositions just the border without altering
the photo.
1. Using any selection tool, click New Selection in the options
bar, and position the pointer inside an existing selection border. The
pointer changes to indicate that you can move the selection .

18.
Modifying Selections
Move a selection border
Moving a selection border repositions just the border without altering
the photo.
2.Do one of the following:
Drag the border to enclose a different area of the photo. You can drag a selection
border beyond the canvas boundaries; however, this makes it hard to get back.
You can also drag the selection border to another image window.
To move the selection in 1-pixel increments, use an arrow key.
To move the selection in 10-pixel increments, hold down Shift, and use an arrow
key.
To constrain the direction to multiples of 45°, begin dragging, and then hold down
Shift as you continue to drag.

19.
Modifying Selections
Invert a selection
Inverting a selection changes the unselected areas into
selected areas, protecting the area you previously selected.
1. In a photo with an existing selection border, choose Select
> Inverse.
.

20.
Modifying Selections
Add to or subtract from a selection
You can add to or subtract from an existing selection to fine-tune
selection borders. For example, you could make a donut-shaped
selection by first making a circular selection and then subtracting a
circular selection within it.

21.
Modifying Selections
Add to or subtract from a selection
Select a selection tool, and do one of the following:
• Hold down Shift (a plus sign appears next to the pointer) to add to
the selection, or hold down Alt (Option in Mac OS) to subtract (a
minus sign appears next to the pointer) from a selection. Then select
the area to add or subtract and make another selection.
• Click Add To Selection or Subtract From Selection in the options
bar, and make another selection. (The Add To Selection and Subtract
From Selection options appear in the options bar when any selection
tool is selected.)

22.
Modifying Selections
Select an area that intersects an
existing selection
You can limit the area a selection affects.
For example, in a picture of snow-capped
mountains, you can select white clouds in
the sky without selecting parts of the
white mountain below them by selecting
the entire sky, and then using the Magic
Wand tool with Intersect with Selection
selected and Contiguous deselected to
select only the white areas included
within the existing sky selection.

23.
Modifying Selections
Select an area that intersects an
existing selection
Select a selection tool, and do one of the
following:
• Select Intersect With Selection in
the options bar and select an area that
intersects the existing selection.
• Hold down Alt (Option in Mac OS) +
Shift so that cross-hairs appear next to
the pointer and select an area that
intersects the existing selection.

24.
Computer Science 2
Thank You…