Adobe Photoshop

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Adobe Photoshop
Lab 2

• Advanced Selection/Manipulation

70-160 Graphic Media Processes Spring 2008
Robert Kaminski (TA) rkaminsk_at_andrew.cmu.edu
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Lab Session 2 Goals

• To learn sophisticated methods of selecting and
  extracting image elements in Photoshop
• To learn digital airbrushing

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Assignment

• Due next by the beginning of the next lab session
• Friday, February 1 _at_ 1230pm
• Save in Photoshop .PSD format (e.g., so I can see
  the layers)
• Use naming scheme
• andrewID-lab2assign.psd
• Ex rkaminsk-lab2assign.psd
• Upload to Blackboard digital drop box

(Next slide has assignment details)
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Assignment
Use what youve learned today and last week

• To put at least 1 World Bank/IMF official at the
  iPod Bar
• Remove iPod Bar sign and replace with something
  else (be clever!)

These image files are in the lab 2 image folder
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Advanced Selection

• Known as masking

• Is non-destructive process (e.g., if you mess up,
  the image data is still there)

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Prepare Canvas

• Open image (flags.jpg), Unlock background
• Create new layer, drag below former background
• Make new layer white

(drag below original image)
1. Double-click
2. Click to create new layer
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Canvas Painting

• Option 1 Paint bucket (for amateurs)

• Option 2 Way-slick shortcut

(paint bucket paints with whatever the foreground
color is)
To make an entire layer the foreground color
(black in this case) ALTBACKSPACE
To make an entire layer the background color
(white in this case) CTRLBACKSPACE
(Windows) CMDBACKSPACE (Mac)
(double-click swatch to choose new color)
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Quick note Zooming

• The process of masking images requires a certain
  amount of precision

• Use the Magnifying Glass tool, click on document
  to ZOOM IN
• Hold down ALT while clicking on the document to
  ZOOM OUT

Magnifying glass SUPER USEFUL
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Lasso Tool(s)

• Lasso tool is used to make selections of
  irregularly shaped objects (i.e., people)
• All lasso selections must form a circle (e.g.,
  the end point must be at the beginning point)

Click and hold down to see other lassos
Lasso click and hold down to draw a free-form
selection (must make a circle, e.g., the end
point must be at the origin) Polygonal Lasso
selection shape is made using straight lines -
to use, clickrelease mouse to start an anchor,
then move the mouse to make line, click again to
end that line (making another anchor) and start
another line Magnetic Lasso regular lasso that
detects edges adjust sensitivity of selection
using, will periodically make anchoring
points Adjust sensitivity using options at bar at
top of screen
Distance from edge to consider for path
Frequency of anchor points
Contrast of edge to consider for path
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Lasso Options

• Once a lasso is completed and selection made
  (marching ants), you can add or subtract from
  the selection
• To draw an additive lasso, hold down SHIFT while
  drawing new lasso
• To draw a subtractive lasso, hold down OPTION
  while drawing new lasso

Original lasso selection
After drawing second additive lasso
After drawing second subtractive lasso
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Marquee Tool(s)

• Will select things (just like Lasoo), but must be
  geometrically perfect (i.e, ovals, rectangles,
  etc etc)

Click and hold down to see other marquees
Types of marquee selection tools
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Saving Selections

• When a selection is drawn and there are marching
  ants, clicking anywhere else on the document will
  unselect your selection
• SAVE all of your work by SAVING your selection

Make sure to give it a descriptive name
SelectSave Selection
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Loading Selections

• If you are working on a selection (that you
  saved) and you mess up or otherwise want to go
  back to your original saved selection, you can
  LOAD your selection

Click Channel drop down box
Find your saved selection on the list
SelectLoad Selection
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Fine-Tune Selection

• Quick Mask tool allows you to paint your
  selection
• Good for fine-tuning/cleaning up selections made
  by lassos

Masked Areas will display everything OUTSIDE your
selection as a painted area
Selected Areas will display everything INSIDE
your selection as a painted area
These options allow you to adjust the color and
transparency of what that painted area will look
lke
Double click to set options before starting
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Using Quick Mask
Selection in Quick Mask mode
Lasso selection
After setting options (previous slide click
once to ENTER Quick Mask mode (click again to
EXIT Quick Mask mode)
(Masked Areas selected in options - previous
slide)
With Masked Areas selected, - Use the Paint Brush
to subtract from the lassod selection - Use the
Eraser to add to the lassod selection
Is opposite if Selected Areas is selected
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Applying Layer Mask

• After using the Lasso and cleaning up with Quick
  Mask,you still need to apply the mask.
• Make sure marching ants are still active ---

Your Layers palette will look like this
Your image will now look like this


Original image
Mask over image

Click once to apply mask
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Editing Layer Masks

• Once masked, you can still edit the selection
  (e.g., modify the mask)

Make sure to select (click) the MASK part of the
layer
Use the Paint Brush to SUBTRACT from the mask
(e.g., add to the selection)

Use the Eraser to ADD to the mask (e.g., subtract
from the selection)
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Deleting Layer Masks

• If you make a mask you dont like, you can simply
  delete the mask portion of the layer

Make sure to select (click) the MASK part of the
layer

Drag to trash can

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Moving on
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Digital "Airbrushing"

• With Photoshop, you can make unfortunate-looking
  people slightly better looking

Wrinkles


Liver spot

Cut/scab?
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Two Tools
Healing brush (best for human faces)
Clone stamp (best for inanimate objects, some
human faces)
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Healing Brush
How it works 1. You pick a brush size 2. Click
on a spot (say that scab from before), 3.
Photoshop will analyze the surrounding area to
determine the image data to fill that spot with

• Advantages
• Very easy fix for spot blemishes

• Disadvantages
• Not suited for lines, very large spots, complex
  textures

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Clone Stamp

• Before Healing Brush was invented, people
  performed the same functions with Clone Stamp Tool

How it works (conceptual) 1. Identify the area
to be painted over (e.g., blemished removed) 2.
You "sample" a representative spot of the
surrounding area 3. You "paint" over the blemish
with the above sampled image data
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Using Clone Stamp

• Hold down ALT and click on an area that to be
  used as the sample
• The cursor turns into a target
• Release ALT
• Click/Drag ("paint") over the blemish
• You will notice the target over your sample
  moving along with the brush

Clone Stamp tips 1. For large areas, re-sample
often 2. Depending on texture of image, adjust
hardness of brush
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Photoshop Last Words

• Adjusting image size/resolution (Image Image
  Size)

When saving for PowerPoint (i.e, screen display
72 InDesign (i.e., printing) 200 or 300
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Photoshop Last Words
(First, when using the image outside of
Photoshop, always flatten it)

• File Formats (File Save As)
• When Saving for
• PowerPoint (I.e., screen display) use JPEG,
  medium compression
• InDesign (I.e., printing) TIFF, no compression