Creative image

manipulation using
Photoshop
Practical workbook

Aims and Learning Objectives

This document aims to introduce the basics of image processing using Adobe Photoshop.
When you have completed these exercises, you should be able to:
• retouch a damaged photograph;
• make selections using a variety of tools;
• adjust the hue and saturation of colours within an image;
• blend images to create a seamless montage;
• add and edit text.

University of Bristol Information Services document photoshop-t2

Creative image manipulation using Photoshop (photoshop-t2)

Document Information

Course documents and files

If you are working in the training room the files you need are in C:\User\Graphics\
If you want to work through the practical tasks shown in this document on your own system, obtain
the necessary files from:
www.bristol.ac.uk/is/info/websupport/resources/photoshop-t1.html

Related documentation
Other related documents are available from the web at:
www.bristol.ac.uk/is/learning/documentation/scanning-t1/scanning-t1.doc

Creative image manipulation using Photoshop (Aug 07)

www.bristol.ac.uk/is/learning/documentation/photoshop-t2/photoshop-t2.doc
If you have any comments or queries about this document mail iser-docs@bristol.ac.uk.
© 2007 University of Bristol. All rights reserved.
Creative image manipulation using Photoshop (photoshop-t2)

Contents
Document Information
Introduction to Photoshop.......................................................................................1
The Toolbox ...................................................................................... 2
Palettes.............................................................................................. 3
Getting help....................................................................................... 5
Colour management .................................................................................................6
Colour settings ................................................................................. 6
Choosing an RGB working space ................................................... 7
Monitor calibration ........................................................................... 8
Task 1 Retouching a damaged photograph .....................................................10
Applying the Dust & Scratches filter to the whole image ........... 10
Applying the Dust & Scratches filter selectively ......................... 11
Using the Clone Tool to correct the remaining blemishes ......... 12
Adjusting contrast and sharpening .............................................. 12
Task 2 Selections using the Marquee Tool ......................................................13
Task 3 Selections using the Magic Wand Tool ................................................14
Task 4 Selections using the Quick Mask mode ...............................................16
Task 5 Selections using the Lasso Tool...........................................................18
Task 6 Manipulating colours .............................................................................20
Task 7 Blending images.....................................................................................22
Creating a new document .............................................................. 22
Blending the images ...................................................................... 23
Task 8 Working with text layers ........................................................................26
Adding a text layer ......................................................................... 26
Adding a text box ........................................................................... 27
Task 9 Creating a customised map...................................................................29
Appendix 1 Resolution and image size for printing .........................................32
Appendix 2 Further resources............................................................................33
General information ....................................................................... 33
Scanning ......................................................................................... 33
Photoshop tutorials........................................................................ 33
Creative image manipulation using Photoshop (photoshop-t2)

Introduction
There is little doubt that the use of digital images in learning, teaching and research projects is
growing. Typical uses include: supporting lectures and other presentations; creating Web-
based instruction and creating digital image archives. Another aspect of digital images is that
they can be delivered on a variety of supports: PowerPoint, Web, image database, CD-ROM,
and print. It is therefore important to be familiar with image digitisation processes in order to
obtain images that will be ‘fit for purpose’.
This document shows you how to apply image enhancement techniques using Adobe
Photoshop CS2.

Prerequisites
This document assumes that you are familiar with the use of a computer keyboard and mouse,
Microsoft Windows-based products and the use of a Web browser such as Netscape or
Internet Explorer.
Creative image manipulation using Photoshop (photoshop-t2)

Introduction to Photoshop
Photoshop is the ultimate Swiss army knife for all your imaging needs, from basic to highly
sophisticated image editing. For example you can simply enhance a photograph (remove red eye
effect and scratches, crop, etc.), or create a complex photo collage or a sophisticated Web
interface. Palette well
Palettes
Menu bar

Option bar

Toolbox

Active image area

Status bar Context menu

The main components of the Photoshop work area are:

• Menu bar - contains menus organised by tasks. For example, the Layers menu contains
commands for working with layers.
• Toolbox - contains tools for creating and editing images.
• Options bar – provides options for the currently active tool.
• Active image area (also called Document window) – displays the active open file. Several
images can be open at the same time, but only one can be active at a time.
• Palettes – help you monitor and modify images. They can be nested by dragging the title tab
of one into the body of another. Use the Window menu to show/hide palettes
Other useful elements are:
• Palette well – helps you organize the palettes in your work area.
• Status bar – located at the bottom of every document window, it displays useful information
about the image and brief instructions for using the active tool.
• Context menu – display commands relevant to the active tool, selection, or palette. You
access them by right-clicking on an image or palette item.
The Toolbox, Palettes and Active image area can easily be moved around the workspace by
clicking the top bar and dragging them.

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Creative image manipulation using Photoshop (photoshop-t2)

The Toolbox
Move Tool
Magic Wand Tool

Crop Tool

Hand Tool Zoom Tool

Set foreground/
background
color

The Photoshop CS2 Toolbox contains all the tools you need for manipulating and creating
images, for example, making selections, cropping, drawing, painting, erasing, moving,
magnifying, etc.
Some of the buttons represent families of tools rather than single tools. For example, the
Rectangular Marquee Tool is the default for selecting geometrical shapes, but if you right-
click on it, a palette pops out with more choices such as an Elliptical Marquee Tool.
Further options are available when you hold down the <Shift>, <Ctrl> or <Alt> keys as you
use a tool. For example, hold down <Shift> to select a circular shape with the Elliptical
Marquee Tool.

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Creative image manipulation using Photoshop (photoshop-t2)

Palettes
Palettes are one of the main means of accessing many of the features of Photoshop. You can
show and hide them using the Window menu. Alternatively, you can press the <Tab> key while
holding down <Shift> to hide/show them all.
Palettes can be moved around or nested (stacked behind one another) by dragging the title tab of
one palette onto the body of another.

To bring a palette to the front, just click its title tab.

You can also expand/collapse them by double-clicking on the title tabs.
If you don’t like having palettes floating
around, you may prefer accessing them from
the Palette well. To add a palette to the
Palette well, simply drag it into it as
illustrated on the right.
Clicking on the right pointing arrow in the
top right corner will bring out a menu specific
to the active palette.

Two of the most useful palettes are the Layers palette and the History palette:

The Layers palette

Layers are an essential part of Photoshop and you need to think of them as the building blocks to
every image that you create. Individual palettes and the toolbar can be displayed or hidden using
the Window menu (those with a tick mark next to them are visible).
The Layers palette enables you to control elements of an image by assigning separate layers to
each individual element. Layers allow you to work on one element of an image without disturbing
the others.

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Creative image manipulation using Photoshop (photoshop-t2)

Blending modes Layers palette menu

Hide/Show layer

Reveals layer effects

Layer name

Layer thumbnail

Delete layer

Link layers Add a layer style

Create a new layer
Add layer mask
Create a new group
Create new fill or
adjustment layer

The idea is that you stack layers (in the same way that you would stack sheets of acetate
transparencies) containing the various elements that will form your final image. There are different
types of layers:
• Image layers are transparent and may contain images or part of images. They can also be
used for drawing, filling with colour, etc. They contain pixel information only.
• Adjustment and fill layers allow you to make colour and tonal adjustments to your image
without permanently changing its pixel values.
• Type layers allow you to insert text in your image. A new Type layer is automatically added
above the active layer when using the Type Tool.
• Shape layers are filled with solid colours and the outline is defined with a vector mask
and/or a layer mask. A new Shape layer is automatically added above the active layer when
using one of the shape tools (Rectangle/Rounded Rectangle/Line/etc Tool).
In addition, you can manipulate each layer individually by applying various styles and effects
(blending, drop shadow, etc.), filters and masks.

The History palette

Every change that you make to your image is recorded in the History palette as a history state.

History palette menu

Create new document

from current state
History state

Create new snapshot

History state slider

Delete current state

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Creative image manipulation using Photoshop (photoshop-t2)

Just click on a state in the History palette to go back to that state (alternatively drag the History
state slider up or down to point to the state you wish to move to). The states below the one you
click on are dimmed and will be discarded if you continue to work from the selected state.
You can also delete states by dragging them into the wastebasket icon in the bottom right corner of
the palette (alternatively right-click on the name of the state you want to delete, then choose
Delete from the pop-up menu). Notice that this action will also delete all the subsequent states.
By default, the History palette will remember 20 states. You can change this by going to
Edit/Preferences/General.

Getting help
Photoshop has a comprehensive help tool (see illustration below). To open it, go to
Help/Photoshop Help.
A-Z Index

Adobe Photoshop Help Center

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Creative image manipulation using Photoshop (photoshop-t2)

Colour management

Colour settings
One problem with imaging software is the issue of screen, scanner and printer inconsistency. For
example, monitor brightness, contrast and resolution all affect the way an image is displayed.
Photoshop includes features to help ensure that screen colours will, as far as possible, resemble
the final image.
As a rule of thumb, the image mode should be set to RGB Color when working for screen display
and CMYK Color for printing. To check this, from the main menu, select Image/Mode.

The reason for this is the differing nature of colour creation between media.
Printers use Cyan, Magenta, Yellow and Black to simulate the full spectrum. This is known as the
subtractive method; remove all of these colours and you will end up with white (hence the
standard paper colour). Adding 100 percent cyan, magenta and yellow would, in theory, result in
black. However, in practice, results are never perfect, so printers include black ink; this is also a
more economical way to work.
Computer screens, along with other digital media such as scanners and digital cameras, replicate
colour using the additive method. Red, Green and Blue are combined to create a range of
millions of colours: Adding 100 percent of each colour results in white light, whereas 0 percent will
render black, in other words, no light.
If converting from a screen image to a printed version, all changes should be made in RGB mode
before a final conversion to CMYK, using the menu shown above. This will remove any colours that
can only be displayed on screen, replacing them with their nearest printable equivalents. If you
need to work on an image that has been saved in Indexed Color mode, you will need to convert it
to RGB Color in order for it to be fully editable. Indexed Color uses a smaller palette to cut down
on file size.
The advantage of working in RGB Color is that you have access to all the bells and whistles of
Photoshop which would otherwise be hidden or greyed out in CMYK Color.

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Creative image manipulation using Photoshop (photoshop-t2)

Choosing an RGB working space

The colour working space refers to the gamut (range of colours) that can be displayed or printed.
This range varies for different RGB working spaces and for different devices and can be changed
in Photoshop.

sRGB IEC-61966-2.1
sRGB is the standard colour space for PC computer monitors and is the colour space assumed by
many applications (including Web browsers and Photoshop). However, it has a limited gamut,
sufficient for on-screen use (e.g. Web design, PowerPoint presentations), but unsuitable for quality
printing, since it clips colours in the CMYK gamut.

Adobe RGB (1998)

Adobe RGB (1998) has become the recommended RGB editing space for RGB files that are
destined to be converted to CMYK for print output. It provides a much wider gamut and
consequently it has a much better ability to capture very deep or bright colours.
The figure on the right shows the full colour gamut (billions
of colours) visible to the human eye. A shows the typical
Adobe RGB (1998) colour space and B the sRGB colour
space.
As you can see, A covers a greater range of colours than
B.
There are other RGB colour spaces that have a much
wider gamut (Wide Gamut RGB), however, these are
intended for highly specialised applications.
To summarise, you should stick to sRGB for images
intended to be used on the Web or for on-screen
Chromatic
presentations, and convert to Adobe RGB (1998) for
diagram
images intended for print (after conversion to CMYK)

• To change the RGB colour space from sRGB to Adobe RGB, go to Edit/Color Settings. In the
Color Settings dialogue box, in the RGB drop-down menu (under Working Spaces) select
Adobe RGB (1998) as shown below:

• To convert from RGB mode to CMYK, go to Image/Mode and select CMYK Color from the
list.

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Creative image manipulation using Photoshop (photoshop-t2)

Monitor calibration
The Adobe Gamma utility comes bundled with Photoshop and can be used to calibrate a monitor’s
settings: RGB colour balance, brightness, contrast and white point (the point at which colour will be
displayed as white).
To launch the Adobe Gamma wizard, go to Settings/Control Panel and double-click on the icon
labelled Adobe Gamma.
The wizard will appear as follows:

Make sure the Step By Step (Wizard) radio button is checked and click the Next button to
proceed.
Leave the default monitor profile selected unless you know of a better match for your screen, in
which case click the load button and choose from the list displayed.
Click the Next button and follow the on-screen instructions to set the brightness and contrast of
the monitor.
Again, click Next to display the Phosphors pop-up. This should be left unchanged, unless you
know for certain that your monitor’s phosphors differ from the default option.
Proceed by clicking the Next button. Uncheck the View Single Gamma Only box and set the
gamma (mid-tone) brightness of your screen for each primary colour by following the on-screen
instructions.

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Creative image manipulation using Photoshop (photoshop-t2)

Assuming you are using a PC, from the dropdown menu, select Windows Default. There is also a
Macintosh option. The Custom setting is only available to Macintosh users.
Having clicked Next to continue, leave the Hardware White Point as displayed unless you know it
is incorrect. Continue to the next screen, leave Adjusted White Point as set and proceed to the
final screen. You have an option to view the screen with before and after settings, before clicking
the Finish button to name and store your monitor’s new profile.
See Ian Lyons’ article, Photoshop CS - Colour Management (www.computer-
darkroom.com/ps8_colour/ps8_1.htm) for a more detailed introduction to colour management.

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Creative image manipulation using Photoshop (photoshop-t2)

Task 1 Retouching a damaged photograph

Objectives To remove scratches and dust spots from an image.
Comments Old or neglected photographs often suffer from a variety of defects (scratches, dust
spots, creases, etc) that devalue them. Photoshop provides a range of tools to
correct these defects and with a little bit of practice it is easy to repair damaged
images.

1.1 Open a new image:

¾ Go to File / Open and in C:\User\Graphics\ open the file old_image_before.jpg
and make a copy of it using the Image / Duplicate command.
¾ Replace the suggested name with old_image_after and close
old_image_before.jpg.

Applying the Dust & Scratches filter to the whole image

1.2 Create a copy of the Background layer by dragging the background layer onto the
Create a new layer icon
You should now have a Background copy layer above your original Background
layer.
1.3 Remove dust and scratches:
¾ Make sure the newly created Background copy layer is selected in the Layers
palette.
¾ Go to Filter / Noise / Dust & Scratches to open the Dust & Scratches dialogue
box (Figure 1).

Figure 1 - the Dust & Scratches dialogue box

¾ Make sure the Radius and Threshold sliders are all the way to the left to start with.
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Creative image manipulation using Photoshop (photoshop-t2)

¾ Slowly move the Radius slider to the right and observe the changes: the spots
disappear, but the image loses its inherent noise or film grain. Settle for a value of 6
pixels.
¾ Now move the Threshold slider to the right until the spots begin to reappear. Settle
for a value of around 25 levels and click on OK.
Note The degree of success you have with the Dust & Scratches filter depends largely
on the image or selection to which you apply it.

Applying the Dust & Scratches filter selectively

Although the spots and scratches are mostly gone and the grain restored, you
probably notice that some of the important detail has been eliminated. The reason is
that the Dust & Scratches filter can’t tell the difference between a scratch and an
eyelash!
To remedy this problem, we’ll use a Layer Mask to hide the filtered image and then
'burn holes' in it to apply the filter only to the damaged areas of the image.
1.4 Go to Layer / Layer Mask / Hide All. You should see a new, black-filled Layer
Mask in the Layers palette (Figure 2).

Layer mask thumbnail

Figure 2 - new layer mask in the layers palette

¾ Make sure the Layer Mask thumbnail is active (it should be framed within a double-
line border); click on it if it’s not.
¾ Make sure foreground colour is set to white in the Set foreground /
background color tools located in the Toolbox (use the double arrow in
the top right corner to inverse foreground and background, if necessary).
¾ In the Toolbox, choose the Brush Tool (Figure 3) and in the Options bar
at the top of the screen, set Opacity and Flow to 100%.

Figure 3 - the brush tool option bar Brush Preset picker

¾ Click the triangle next to the Brush Preset picker and choose a soft-edged brush
tip about the size of the specks you need to hide (about 17 px).
¾ Dab with the Brush Tool where you see specks in the image.
Notice the changes on the Layer Mask thumbnail in the Layers palette.
Note The dabs are like burning little white holes in the mask, allowing the filtered image to
cover the spots in those areas.
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Using the Clone Tool to correct the remaining blemishes

Next you will add a “repairs” layer above the filtered layer, where you can make your
“hand-painted” alterations. This protects the image from painting mistakes and also
makes it easy to make changes to your repairs later if you need to.
1.5 Add another layer by clicking on the Create a new layer icon at the bottom
of the Layers palette.
¾ Choose the Clone Stamp Tool in the Toolbox, and in the Options bar set
the Opacity low (for example 30%) and select the Use All Layers check
box (Figure 4).
Brush Preset picker

Figure 4 - the clone stamp tool option bar

¾ Click the triangle next to the Brush Preset picker and choose a soft-edge brush tip
(for example, 17 px) about the size of the specks you need to hide.
¾ To start the repairs, hold down the <Alt> key and click in an area near the flaw you
want the repair to sample from. Release the <Alt> key and move the cursor over to
the point where you want to clone to and click, several times if necessary, to cover
the flaw.
Note The Clone Stamp Tool works by sampling colours in an area and copying (cloning)
them to a damaged area. This is a fiddly job which requires frequent sampling, but
which can ultimately give excellent results.

Adjusting contrast and sharpening

Finally, you could refine your image by adjusting tone, colours and sharpening using
the methods described in Tasks 3 and 4.
For this task, we are simply going to apply a “quick fix” to adjust the image contrast.
1.6 Click the Create new adjustment layer icon at the bottom of the Layers
palette and choose Levels.
¾ Click on Auto and then click on OK.
1.7 Save your image:
¾ Go to File / Save As.
¾ In the Save As dialogue box, navigate to:
C:\User\Graphics\.
¾ Save your file as old_image_after as a JPEG with maximum quality.
1.8 Open old_image_before.jpg to compare it side by side with old_image_after.jpg.
Observe the differences.

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Task 2 Selections using the Marquee Tool

Objectives To “frame” a selection with a clear geometrical shape, you can use either the
Rectangular or Elliptical Marquee Tool.
Comments Selecting parts of an image is an essential skill in Photoshop. It is often the starting
point for further manipulations, such as combining images together and applying
filters/effects or making tonal adjustments to part rather than all of the image/layer
you are working on.

2.1 Select part of an image with the Marquee Tool:

¾ Open the photograph manneken_pis.jpg in C:\User\Graphics\ and duplicate it
(Image / Duplicate).
¾ In the Toolbox, right-click on the Rectangular Marquee Tool (right) and
select the Elliptical Marquee Tool.
¾ Select an area of the image (for example the head of the statue) – it is easier to
select from top-left to bottom-right.
TIP: Hold down the <Shift> key as you draw your marquee, to obtain a circular or
square shape, rather than an elliptical or rectangular shape.
¾ Reposition your selection if necessary by clicking inside it and dragging to a new
position.
Note You can add to selections by holding down <Shift>, or subtract from a selection by
holding down <Alt> (alternatively you can use the Add to selection or Subtract
from selection buttons in the Options bar – see Figure 5).
¾ Experiment using the Add to selection, Subtract from selection options,
modifying the feathering (Figure 5) and using the Rectangular Marquee Tool if you
want.
Add to selection Subtract from selection
New selection Intersect with selection

Figure 5 - the Marquee Tool Options bar

Note Feathering creates a soft edged border around the selection that blends gradually
into the background. This technique is known as vignetting.
2.2 Use your final selection to create a vignette image:
¾ Using the Set foreground / background color tools located in the Toolbox, set the
background colour to white or black.
¾ Go to the Select menu and choose Inverse. This will inverse the selection so that
the area outside your selection becomes selected (notice the marching ants around
the edges of the image).
¾ Press the <Delete> key to get rid of the inversed selection area. You should be left
with a cut-out of the statue blending smoothly with a black or white background.
¾ Close these images without saving.

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Task 3 Selections using the Magic Wand Tool

Objectives To select an area defined by colour.
Comments The Magic Wand allows selections by colour-matching. It is particularly useful when
selecting an area containing pixels whose luminosity values are close, such as a
blue sky for example.

3.1 Select part of an image with the Magic Wand:

¾ Open the photograph willstower.jpg in C:\User\Graphics\ and duplicate it (Image /
Duplicate).
¾ In the Toolbox, select the Magic Wand Tool (see right).
¾ In the Options bar, select the Add to Selection option (Figure 6).

Add to selection

Figure 6 - the Magic Wand Tool Options bar

¾ Set Tolerance to 1 and make sure Contiguous is checked.

Note The Tolerance option controls the range of pixels that will be included in the
selection on either side of the pixel you click on. The Contiguous option only allows
neighbouring areas to be selected. If it is unchecked, similar colours in unrelated
parts of the image will also be selected.
¾ Click four or five times in different parts of the blue sky area, noting the low
tolerance. Change the tolerance to 10 and continue; you will notice that the whole
sky soon becomes selected, outlined by a marquee (Figure 7).

Figure 7 - sky selected using the Magic Wand Tool

3.2 Add a gradient to the selection:

¾ In the Toolbox, select the Gradient Tool (see right) – if it is not displayed,
right-click on the Paint Bucket Tool and select it from the list.

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¾ Referring to the tool options bar, near the top of the screen, make sure Linear
Gradient is selected (Figure 8).
Linear Gradient

Figure 8 - the Gradient Tool Options bar

¾ In the Toolbox, click the Set foreground color square to launch the Color Picker
palette. For optimum flexibility, ensure that the option Only Web Colors is
unchecked. Choose a medium dark to dark colour and click OK.
¾ Repeat for the Set background color square, this time choosing a lighter shade of
the colour you selected for the foreground.
¾ Place the cursor against the left-hand side edge of the blue selection and, holding
down the left mouse button, drag the cursor in a straight line to the right edge of the
sky and release.
You will notice that a gradient has been applied, but only to the selected area. If you
are unhappy with the result, you can simply drag a new gradient over the selected
area.
¾ Click <Ctrl> + D to deselect the sky. Alternatively, go to Select / Deselect.
¾ Close the image without saving.

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Task 4 Selections using the Quick Mask mode

Objectives To select an irregular area by filling it in.
Comments Working in the Quick Mask mode, you can isolate an area by painting over it.

4.1 Select part of an image in Quick Mask mode:

¾ Open the photograph hockey.jpg in C:\User\Graphics\.
¾ Select the Edit in Quick Mask Mode icon, situated below the
foreground/background Color Picker (Figure 9).

Edit in Standard Mode

Edit in Quick Mask Mode

Figure 9 - Standard/Quick Mask Mode icons

¾ Select Brush Tool from the Toolbox.

¾ Click the Brush Preset picker in the options bar (Figure 10).

Figure 10 - the Brush Tool Options bar Brush Preset picker

¾ The Brush Preset picker displays brushes varying in hardness and diameter.
Choose a hard brush (indicated by a sharp circle), and set the size to 16.
¾ Paint over the area you wish to select, in this case the middle hockey player (ignore
the hockey stick) Note how the selected area is highlighted in semi-transparent red
(Figure 11).

Figure 11 - Quick Mask applied to middle hockey player

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Creative image manipulation using Photoshop (photoshop-t2)

¾ When you have finished, revert to the Edit in Standard Mode (see Figure 9) –
notice the marquee (marching ants) around the hockey player and around the edges
of the image.
¾ If necessary, tidy up the edges by returning to Edit in Quick Mask Mode, using the
Brush Tool to add to, and the Eraser Tool to subtract from the selection.
¾ Once you are happy with your selection, make sure you return to Edit in Standard
Mode and in the Select menu, choose Inverse.
4.2 Create a simple photo montage:
¾ Open the photograph royalfort.jpg in C:\User\Graphics\.
¾ Return to image hockey.jpg and, having selected the Move tool (see
right), place the cursor on the highlighted hockey player and drag the
selection on to the Royal Fort image. A new, independent layer will be
created.
¾ Position the hockey player where you want it on the Royal Fort image.
¾ Check that the top layer containing the hockey player is highlighted in the Layers
palette.
¾ Select the Clone Stamp Tool (see right) and in the Options bar set
Opacity to 100%, Flow to 68%, and make sure the box labelled Use All
Layers is checked.
¾ ‘Clone’ the flowers surrounding the hockey player, and use them to paint over the
join in the images (see Task 7.5).
¾ If any traces of hockey stick are visible in the player’s hand, try using the same
technique to remove them.
¾ Save the image as success.psd in C:\User\Graphics\.

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Task 5 Selections using the Lasso Tool

Objectives To explore a shortcut to select a well-defined but irregular shape.
Comments The Lasso Tool is useful for selecting irregular shapes. There are three versions
which come under one icon in the Toolbox.

• The default Lasso Tool is a free-hand tool useful to select very detailed
edges and requires a good deal of practice and patience! To use it,
hold down the left mouse button and drag a line around the desired
area. Then release to make the selection.
• The Polygonal Lasso Tool enables you to select a series of short,
straight line segments, which makes it better to select shapes with a
smoother edge. To use it, click the left mouse button once and move
the mouse around the image, clicking each time you change direction. A series of
nodes will be created to join the lines. When you arrive back at the starting point,
click on the first node to create the selection.
• The Magnetic Lasso Tool has as sensing area (that can be changed
in the Options bar). When you move the cursor along the edges in a
picture, the Magnetic Lasso can sense where that edge is and create
a selection that follows it. It is probably the most useful of the three lasso tools.
5.1 Make a selection with the Magnetic Lasso Tool:
¾ Open the image autumnleaf.jpg in C:\User\Graphics\.
¾ Select the Magnetic Lasso Tool (right-click on the Lasso Tool icon in the Toolbox
and choose Magnetic Lasso Tool).
¾ In the Options bar, set Feather to 5px and accept the default Anti-alias, Width,
Edge contrast and Frequency options (Figure 12).

Figure 12 - Magnetic Lasso Tool Options bar

Note You can change the settings in the Options bar for the Magnetic Lasso Tool:
Feather creates a soft edged border around the selection; Anti-aliased smoothes
the jagged edges of a selection; Width sets the radius of the area where the tool
looks for the edge; Edge Contrast specifies how much contrast the tool should look
for in finding the edge and Frequency specifies how often locking points are laid
down.
¾ Place the cursor anywhere on the edge of the main leaf, release the mouse button
and drag the cursor around the leaf – notice how the tool automatically follows the
edge created by colour or tone contrast.
¾ If you make a mistake, just press <Delete> to undo a segment. Where there is no
contrast for the Magnetic Lasso Tool to follow, regularly click on the edge to
increase the frequency of locking points.
¾ When you have come full circle, click the node at the starting point to make the
selection.
5.2 Create a simple montage
¾ Leaving the selection active, open image C:\User\Graphics\grass.jpg

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Creative image manipulation using Photoshop (photoshop-t2)

¾ Return to the autumn leaf image and using the Move tool drag the selection
on to the grass image, positioning it in the centre (see Figure 13).

Figure 13 - leaf superimposed on grass background

¾ Working in the Layers palette, make sure the leaf layer is highlighted, and click the
small back triangle to the right of the Opacity box to launch a slider (see Figure 14).

Figure 14 - Opacity settings in the Layers palette

¾ Move the slider gradually to the left to increase the transparency of the layer.
¾ Set the slider to around 65% before saving the image as grassleaf.psd by selecting
File / Save As in the main menu.

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Task 6 Manipulating colours

Objectives To change the hues and colour-saturation within whole images and individual colour
channels.
Comments This is achieved by the addition of a Hue / Saturation adjustment layer and requires
no use of selection tools.

6.1 Open the photograph crayons.jpg in C:\User\Graphics\

6.2 Add a Hue / Saturation adjustment layer
¾ Click the Create new adjustment layer icon at the bottom of the Layers
palette and choose Hue / Saturation. This will launch the palette shown in Figure
15.

Figure 15 - Hue / Saturation palette

6.3 Adjust the hue and saturation of the whole image:

¾ Making sure Master is selected in the Edit menu, gradually move the slider labelled
Saturation to the far left. Note that the colour gradually drains from the image, to
create a greyscale version.
¾ Move the Saturation slider gradually to the far right, noting how the image gradually
becomes over-saturated with colour.
¾ Move the Saturation slider to the point you feel most appropriate (0 if no adjustment
is deemed necessary).
¾ Experiment with the Hue slider, noting the shift of each colour along the spectrum,
before resetting it to 0.
6.4 Adjust individual channels
¾ Select the Yellows channel from the Edit menu (see Figure 16).

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Figure 16 - selecting a channel within the Hue / Saturation palette

¾ Slide the Saturation slider to the far left. Note how each instance of the colour
yellow gradually becomes greyscale. Replace the slider at 0.
¾ Gradually move the Hue slider to the left, noting how all the yellows move through
the spectrum, without affecting other colours. Settle on a value of –25, to replace the
bright yellow crayon in the foreground with an orange version.
Note Where shadows occur in the image, applying too great a change will render the
image unnatural. You can, however, mask areas you do not wish to affect by
making a selection, using the tools covered in tasks 2.- 5.
¾ Experiment, repeating the above processes for other channels, before closing the
image without saving.

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Task 7 Blending images

Objectives To merge images together in a smooth transition.
Comments This technique is ideal for creating seamless photomontages.

Creating a new document

7.1 Create a new file:
¾ Go to File / New. In the New dialogue box, give your new image a name (e.g.
firstmontage), set the Width to 300 pixels and Height to 100 pixels, the Color
Mode to RGB Color and Background Contents to White (Figure 17).

Figure 17 - New file dialogue box

7.2 Move images to the new document:

¾ Open the image library.jpg located in C:\User\Graphics\.
¾ Using the Move tool (see right), drag the image library.jpg on to the new
blank image.
Notice that a new layer containing the image has been created above the white
Background layer.
Note If rulers are not displayed, click View / Rulers. Right-click somewhere inside the
ruler and set the unit of measurement to Pixels.
7.3 Resize the image to make it smaller:
¾ Ensure the top layer is selected in the Layers palette. In the Edit menu, select
Transform / Scale.
This will display sizing handles around the image – if you cannot see the handles,
you can increase the canvas size by dragging its edges.
¾ Hold down <Shift> to preserve the aspect ratio, and move the corner points inwards
until you can see enough of the student in the image.

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As you do this, you can reposition the image by placing the cursor inside the
transform boundaries, pressing the left button and dragging. Drag the image to the
right of the canvas, leaving approximately 1/3 of the canvas uncovered and
experiment with vertical alignment until you are happy with the position of the
student (see Figure 18).

Figure 18 - scaling down and positioning the library image

¾ Click <Enter> to commit the change. At this point, you can reposition the image if
you wish.
Note If the image keeps snapping to edges of the canvas, turn the Snap feature off by
selecting View / Snap and making sure the Snap option is unchecked. Repeat this
process to reset it if required.
7.4 Repeat steps 7.2 and 7.3 with the image computer.jpg, aligning it left, overlapping
the library image. It should cover just over ½ the canvas (see Figure 19).

Figure 19 - two overlapping layers

Note It is important that the images overlap sufficiently for the blending effect to work.

Blending the images

7.5 Blend the images as follows:
¾ Make a note of the computer image’s right edge on the horizontal ruler (around 150
to 170 pixels), and in the Layers palette, make sure Layer 2 (the computer image)
is selected.
¾ Then in the menu bar at the top, go to Layer / Layer Mask / Hide All to add a layer
mask.

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You should now see the layer mask as illustrated in Figure 20.

Figure 20 - layer mask applied to top layer

This renders the layer invisible, indicated by a black thumbnail in the layers palette.
Various tools can be used to ‘paint the layer back’. In this case, the
Gradient Tool is used to achieve a smooth transition from transparent to
fully visible.
¾ Having made sure the foreground colour is set to black, select the
Gradient Tool (if you can’t see it, right-click on the Paint Bucket Tool
and select it).
¾ Make sure the layer mask (black thumbnail) is highlighted in the Layers palette, by
clicking on it once. If the image icon itself is highlighted, a colour gradient will flood
the layer.
¾ Place the cursor just inside the right-hand edge of the computer image (refer to the
note you made earlier), roughly in the middle vertically. Click and hold down the left
mouse button and drag the mouse to the left, in a straight, horizontal line, stopping
just on the left edge of the library image, and release.
You will notice the computer image gradually appearing. The image becomes 100%
visible at the point at which the mouse is released. You will notice that the black
thumbnail now displays the applied gradient (Figure 21).

Figure 21 - layer mask after the Gradient Tool has been applied to it

If you are unhappy with your gradient, simply click and drag the mouse again. The
shorter the drag, the less gradual the transition between invisible and opaque.
Your blended image should look something like Figure 22.

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Figure 22 - layers gradually blended together

7.6 Link the two layers:

¾ In the Layers palette, select one of the image layers, press <Shift> and select the
other image layer.
¾ With the two image layers selected, click on the Link layers icon at the bottom of
the Layers palette (Figure 23).

Link layers icon

Figure 23 - linking the two image layers

Notice the link symbol now displayed to the right of each image layer, indicating that
these layers are linked.
Note Linking layers is particularly useful when you want to apply the same changes (e.g.
repositioning, styles, etc.) to several layers.
7.7 Merge the layers:
¾ In the Layers menu, select Merge Layers. As a result the two linked layers will
become one (Figure 24).

Figure 24 - merged linked image layers

¾ Save the image as firstmontage.psd in C:\User\Graphics\.

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Task 8 Working with text layers

Objectives To add and manipulate text layers.
Comments You can create type (text) anywhere in an image in Photoshop. When you create
type, a new type layer is added to the layers palette. You can then manipulate it like
any other object (image, shape, selection, etc), and the text itself will remain
editable.

Adding a text layer

8.1 Create a new image with dimensions 400px x 400px with a white background (see
task 7.1)
8.2 Activate the Type tool:
¾ In the Toolbox, select Type tool and left-click inside your new canvas.
¾ In the Type tool Option bar (Figure 25) click on the Set the text color option and
pick colour for your text:
Toggle the Character and Paragarh palettes

Figure 25 - the Type tool options bar

Set the text colour Create warped text

¾ Choose a font family, style and size from the font options (for example Arial, 18pt,
bold, Sharp).
Note Working at different image resolutions will result in variations in apparent text size.
For example text will appear much smaller in a 300dpi image than in a 72dpi (typical
screen display resolution) image.
8.3 Add some text:
¾ Click inside the canvas, toward the top left and note the automatic addition of a new
layer in the layers palette.
¾ Type your name (Figure 26). To deselect the Type tool, click the Commit icon in
the Tool Options menu. You should notice the text in the layers palette change to
match the name you have typed (Figure 27).

Figure 26 – Example of type layer

Figure 27 – Type layer indicated in layers palette

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8.4 Set anti-aliasing:

¾ Make sure the type layer is selected in the layers palette and select the Type tool.
¾ Experiment with the anti-aliasing options on the drop-down menu on the tools
options menu), noting how the text changes, settling with which ever you feel
renders the text most clearly.
Note Anti-aliasing smoothes jagged edges by adding shading or colours.
8.5 Reformat and edit the text:
¾ Making sure the type layer is highlighted, select the Type tool and click just to the
right of the final letter of your text.
Note It is important you do not click anywhere else in the document; this will result in the
creation of a new text layer
¾ Hold down the left mouse button and drag to highlight all of the text.
¾ Experiment with font faces, sizes, colours and anti-aliasing options.
¾ Left-click within the text and use the keyboard to change your name to Joe Bloggs

Adding a text box

8.6 Use the shape tool to create a box with a drop shadow to set it away from the
background:
¾ Create a new layer (see Task 1.5).
¾ Select the Shape tool in the Tool Box
¾ In the Tool Options menu, make sure the Fill pixels and Rectangle tool icons are
selected (Figure 28).

Figure 28 - Fill pixels and Rectangle tool selected

¾ Set the foreground colour by clicking the foremost square on the colour picker and
choosing a pale colour from the palette.
¾ Working on the layer you have just created, place the cursor below the text you
have already created, hold down the left-hand mouse button, and draw a rectangle,
large enough to accommodate your text.
Note Hold down the shift key when dragging, to achieve a perfect square
¾ Add text, as per task 8.2
8.7 Resize and move the text box if necessary:
¾ Make sure the Shape (text box) layer is selected in the Layers palette and go to
Edit / Transform / Scale to display sizing handles.
¾ Drag the sizing handles to resize the image to accommodate the text above, and
either press the return key, or click the Commit icon in the Tool Options menu.
¾ Select the Text layer in the Layers palette and use the Move tool to position the
text inside the box.

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Note In order that your Shape layer does not obscure the text, make sure that it is below
the Text layer in the layers palette. To reorder layers, simply drag them up or down
in the Layers palette.

8.8 Add a drop-shadow:

¾ In the Layers palette, make sure the Shape layer is selected and click the Add a
layer style icon at the bottom (Figure 29).
Add a style layer icon

Figure 29 - the Add a layer style icon in the Layers palette

¾ From the pop-up menu, select Drop Shadow. This will launch the Drop Shadow
Options palette, adding a default shadow to the text.
¾ Experiment with the Structure options (Blend Mode, Colour, Opacity, Angle,
Distance, Spread and Size) and click the OK button when you are happy (Figure
30)
Note Layer styles are applied to every object within a layer. For example, two shapes on
one layer will both acquire a drop shadow.

You may wish to link the two layers to maintain their relative positions (see task 7.6)

Figure 30 – Text box

Further text editing is possible via the Paragraph and Character palettes (open by
clicking the Toggle the Character and Paragraph palettes icon on the Type Tool
Options bar. The Paragraph palette enables line spacing, alignment and so on to
be set. The Character palette provides a shortcut to several formatting elements
also found elsewhere (anti-aliasing, font colour, font size etc.)

You can also warp text in many different ways by using the Create warped text
option. Feel free to experiment with these.
8.9 Minimise the image for reference throughout task 9.

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Task 9 Creating a customised map

Objectives To add text layers to an existing image.
Comments In this example, the objective is to create a customised map.

9.1 Examine an existing customised University map:

¾ Open the following page in a web browser:
http://www.bris.ac.uk/is/locations/findus/branchlocations.html
¾ Note the use of numbers and letters to denote locations of branch libraries and other
Information Services resources around the University. These have been added to a
blank, generic map of the University.
Note Numbering and text may be added to the map to customise it, but for consistency, it
is requested that no other alterations be made.
9.2 Open and prepare a local version:
¾ Open the image precinct-map.tif in C:\User\Graphics\
¾ Go to Image / Mode / RGB Color
¾ Go to Image / Image size to display the palette shown in Figure 31.
Note The image mode has been set to CMYK, for printing, and should be changed to
RGB for screen display. For further information see the Colour Management section
on page 6.

Figure 31 - Image Size palette

¾ Make sure all boxes are checked and the Resample Image menu displays Bicubic
Smoother.

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¾ Set the Resolution to 96 pixels/inch (maximum Windows monitor resolution) and

then the Width to 800 pixels, noting the Height change accordingly (proportions
have been constrained).
Note It is important to set the resolution before resizing the image, as a change in
resolution will always affect the dimensions of the image, whereas changing the
dimensions will not affect the resolution.
¾ Click OK

Using the Zoom tool in the Toolbox, click on the map to zoom into the area around
your own department/unit at 100% image size (see Figure 31 and
9.3 Figure 32). Hold down the <Alt> key whilst clicking, to zoom out if necessary.

Figure 31 - map detail showing Tyndall Avenue and St Michael’s Park

Figure 32 - image size and mode

University buildings are shown as white shapes. For example, Figure 31 shows,
from left to right:
• Senate House
• Sports Hall
• Computer Centre
• Arts & Social Sciences Library
9.4 Customise the map for your department/unit
¾ Using the elements covered in task 8, add appropriate text to label the map, using
text boxes to overcome space issues.
You may wish to use the Line tool to point the box to buildings. This can be found
within the Shape tool options menu – see Figure 33)

Figure 33 – Line tool selected in Shape tool options menu

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To add arrowheads to lines, click the small triangle to the right of the shapes to
select from the drop-down menu shown in Figure 34

Figure 34 – Arrowheads menu

9.5 Save your map:

Go to File / Save for Web and select file type GIF, with 256 colours (see
¾ Figure 35).
¾ Click Save, saving the file as localmap in C:\User\Graphics\

Figure 35 - Save for Web options

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Appendix 1 Resolution and image size for printing

Print size at:
Pixel size Megapixels RGB size CMYK size 150 ppi 300 ppi
(MB) (MB)
1600 x 1200 2 6 7.5 11 x 8 inch 5.5 x 4 inch
(28 x 20 cm) (14 x 10 cm)
2400 x 1800 4.3 12.5 16.5 16 x 12 inch 8 x 6 inch
(40 x 30 cm) (20 x 15 cm)
3000 x 2000 6 17.5 23.5 20 x 13 inch 10 x 6.5 inch
(51 x 33 cm) (25 x 16.5 cm)
3500 x 2500 8.75 25 33.5 23 x 17 inch 11.5 x 8.5 inch
(58.5 x 43 cm) (29 x 21.5 cm)
Table 1 – comparison of pixel resolution, megapixels, megabyte file size and print output dimensions
at different resolutions in inches (and centimetres)

Output use Screen ruling x 1.5 Standard quality x 2 High quality

output resolution output resolution
Newspaper 65 – 100 lpi 97 – 150 ppi 130 – 200 ppi
Books 120 – 150 lpi 160 – 225 ppi 240 – 300 ppi
Colour magazine 150 – 175 lpi 225 – 262 ppi 300 – 350 ppi
Art book/magazine 175 – 250 lpi 262 – 375 ppi 300 – 500 ppi
Photo quality inkjet printer 150 – 300 lpi 225 – 450 ppi 300 – 600 ppi
Table 2 – rule of thumb screen resolutions for common print devices at lpi x 1.5 and x 2 quality
factors

Example
Say you want to print a high quality A4 photograph on an inkjet printer:
A4 size = Width 8.268 x Length 11.693 inches (21 x 29.7 cm)
Printer resolution = 200 lpi
Quality factor = x 1.5
Print length x Printer resolution x Quality factor = number of pixels required in length
11.693 x 200 x 1.5 ≈ 3500 pixels in length
Print width x printer resolution x Quality factor = number of pixels required in width
8.268 x 200 x 1.5 ≈ 2480 pixels in width

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Appendix 2 Further resources

General information
TASI (Technical Advisory Service for Images) – http://www.tasi.ac.uk
The advice section is highly informative. Any question that you may have regarding
all stages of image digitisation will be answered. The sub-section entitled ‘Creating
Digital Images’ is particularly relevant to this course.
Internet for Digital Photography – http://www.vts.rdn.ac.uk/acl/tutorial/digiphoto

Scanning
Apart from the TASI website, you may find the following site very useful for all
scanning issues:
A few scanning tips, by Wayne Fulton – http://www.scantips.com

Photoshop tutorials
These tutorials cover most things you can do in Photoshop, including some useful
tutorials on image enhancement and restoration:
Adobe’s Photoshop tutorials – http://www.adobe.com/products/tips/photoshop.html
Janee’s Photoshop tutorials – http://myjanee.home.insightbb.com/tutorials.htm
‘Computer Arts’ Photoshop tutorials – http://www.computerarts.co.uk/tutorials/2d/

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