Adobe Photoshop CS4 program window...Adobe Photoshop CS4 program window . Dominic White Page 2 12/06/2012 ... These little pixels combine to make up the image; the more pixels you

Dominic White Page 1 12/06/2012

This is how the Adobe Photoshop CS4 program window will look when first opened. The

window can be controlled by the three buttons in the top right hand corner.

The first button minimizes the window and the second maximizes /restores the

window. The last button closes the window; in this case the close button is on the

program window, meaning Photoshop will shut down. If you have unsaved work in the program

window, a message will pop up asking if you want to save your work. Note that minimize and

close buttons can also be seen on active and inactive document windows. (See page 8)

Also found in the top right hand corner of the program window is the

Workspace Switcher. This allows you to swap between different

default program window layouts.

Adobe Photoshop CS4 program window


The Menu Bar

The Menu bar contains drop-down menus in each of the categories shown.

At its most basic, the File menu lets you create, open, save

and print a file, as in many Windows programs.

Browse in Bridge opens a new program that allows you to

easily access documents on your computer/removable

media, viewing them as thumbnails.

The Revert option (F12) is useful if image editing has gone horribly wrong, as it will revert the

active document to its last saved version.

The Edit menu allows you undo and redo actions and cut,

copy and paste selections, again as in many Windows

programs,

Unlike other Windows programs, in which the undo option

(Ctrl+Z) allows you to undo each previous action in order of

occurrence, undo becomes redo, reapplying the action

performed.

In order to undo a number of sequential actions, select Step Backward (Alt+Ctrl+Z).


The Image menu allows you to directly affect the image

you are working with.

Options range from making the image black and white to

resizing the image.

The Select menu is used to select the whole image, deselect

and reselect selection areas and invert a selection that has

been made.

Menu Bar Icons

The icons found in the menu bar are shortcuts to tools, options or display controls. From the

left, these icons are:

Launch Bridge

View Extras; Show Guides, Grids and Rulers

Zoom Level

Hand Tool; used to move around an image in the active document window

Zoom tool; used to zoom in on an image

Rotate View Tool; used to rotate an image in the window, for ease of use

Arrange Documents; used to change how active document windows are shown on screen

Screen Mode; used to switch between Standard, Full Screen with Menu Bar and Full

Screen Mode

Menu options will be looked at in greater detail as they are used in this booklet.


The Options toolbar

This toolbar is used to select options available to the tool you have selected from the toolbox.

In this instance the brush tool has been selected. The number of options available depends

on the tool in use, ranging from 2 to over 16 options.

When using Photoshop, it is important to remember that the

tools you use will remain set to the options selected when last

used.

Whenever you begin a session with Photoshop, right-click the mouse cursor within the tool

icon, at the left of the options toolbar, and select Reset All Tools.


The Toolbox

(Letters in brackets are shortcuts

to that tool from the keyboard)

Rectangular Marquee tool (M)

Lasso tool (L)

Crop tool (C)

Move tool (V)

Quick Selection tool (W)

Eye Dropper tool (I)

Spot Healing Brush tool (J) Brush tool B)

Clone Stamp tool (S) History Brush tool (Y)

Eraser tool (E) Gradient tool (G)

Smudge tool (R) Dodge tool (O)

Path Selection tool (A)

Horizontal Type tool (T) Pen tool (P)

Rectangle tool (U)

3D Orbit tool (N)

Hand tool (H) Zoom tool (Z)

Foreground Colour Switch Foreground and

Background Colour (X)

Background Colour Default Foreground and

Background Colours (D) Toggle Switch:

Standard/Quick Mask Mode

(Q)

Toolbox Toggle Switch:

Screen Length/Compact toolbox

3D Rotate tool (K)


Foreground and Background Colour

The foreground colour shows the colour used if the brush or type tool is used on an image. In

this instance, text would be in black. The background colour will be used if an area of the

image is erased or moved/cut through a selection process (marquee, lasso, magic wand, type

mask). As with resetting the tools to default when you begin a session, it is best to reset the

foreground and background colours to default (by clicking the Default Foreground and

Background Colours button). The colours can be swapped by clicking the Switch Foreground

and Background Colours button.

If a tool icon shows a black right-pointing arrow, it means a number of tools are housed within

that one area. To access different tools from one button, either:

Press and hold the left mouse button over the tool icon until the sub-menu pops out

Right click the tool icon and the sub-menu will pop out

One the sub-menu it seen, left click the desired tool in the list to select it.

If using the short-cut keys, pressing and holding the Shift key while clicking the short-cut

key will scroll though the tools available.

These tools, along with their subsequent options toolbar settings, will be looked at in more

detail as they are introduced in this booklet.


Panels

Panel groups refer to a selection of like panels in one area. Separate panels within that group

can be selected by clicking on the tab stating their name.

In Basic workspace mode, all panels will be collapsed on

the right-hand side of the screen. The toggle switch found

at the top of this bar expands or contracts all panels, much

like to toggle switch found on the toolbox.

To expand an individual panel, click on its icon within a group.

Panels are used to select options for tools currently in use, such as brush size and colour, or

to give information on actions and tasks being performed on the image.

The information displayed in a panel can be altered using the panel menu button, with options

selected from that drop-down menu.

As with individual tools, panels will be discussed in more detail as they are put to use in this

booklet.

Collapsed Panel Icons

Collapse Panel Group

Panel Menu

Panel Groups


Active Document Window

By default, images opened

in Photoshop will be placed

in the centre of the work

area, with large grey areas

around the outside of the

image. When the mouse

cursor is inside this grey

area, the tool in use is still

‘active’.

The tab to the top left of the window tells you the name and file type (extension) of the open

document and has a close button to close the image. If a second image is opened, it will

appear in the same document window (by default), under a second tab. Moving between open

documents is accomplished by clicking these tabs.

The arrange documents button in the menu bar can be used to change how

multiple images appear on screen. The thumbnails to the top of the drop-

down menu allow you to show sections of images on screen at the same

time.

Float All in Windows opens all images in separate document windows,

which then have minimise, maximize and close buttons to the top right of

the window.

New Window lets you open duplicate images in further document windows.

Be aware that you can ‘drag and drop’ document

windows in and out of the ‘main’ active window.


Resolution, File types and

Printing

This section deals with the size of your digital image and how

this affects aspects such as image clarity, the best way to save

your work and print size.


Resolution

Resolution is a very important factor when working with digital images. Every photograph

that you take with a digital camera and image that you see in Photoshop is made up of pixels.

A pixel is one small square of colour and tone. These little pixels combine to make up the

image; the more pixels you have to capture variations in colour, the more defined and

‘realistic’ the image

The number of pixels that make up an image is determined by the device used to capture that

image. If you are working with a 3 mega pixel (mp) camera, the resultant image will contain 3

million pixels. If your camera is 6 mp, the captured image will be made up of 6 million pixels.

This has a direct relationship not only to image quality, but image size (see below). With more

pixels, better colour definition is present and subtle variations in tone can be captured.

When working with Photoshop, the pixel

dimension of an image is the number of

pixels along the width and height of the

image.

This shows an image with a pixel dimension

of 800 pixel width and 600 pixel height.

That means the image contains (800x600=)

480,000 pixels

The document size shows the physical dimension of the image. By default, Photoshop opens

images with a resolution of 72 pixels per inch (ppi), meaning 72 of the million plus pixels

available are shown in an inch. This image is 11” wide by 8” high. A 6 mp image has a 2816

pixel width and a 2120 pixel height; at the same resolution, that makes the 6 mp image 39”

wide by 29” high. If these two images were printed at 6”x4”, the 6 mp image would be of

better definition, as more pixels are ‘crammed’ in to that size.


File Types

JPEG (Joint Photographic Experts Group): The JPEG file type is commonly used in digital

cameras. This file works through compressing the image, thereby reducing the file size. It

does this by selectively discarding data, making it a lossy file type. This type is good when

saving continuous tone images; sharp lines, curves and blocks of colour may become

compromised. The amount of compression can be selected when recording in the camera or

saving on a computer. High compression will lead to a small file size and low compression will

create a larger file size. When opening a JPEG file, it must be decompressed. Depending on

the amount of compression, compression artefacts or noise may be apparent. This is caused

by the compression size chosen deleting colour gradation and replacing it with one colour tone.

JPEG documents have a maximum file size of 2 gb.

TIFF (Tagged-Image File Format): Some digital cameras can record in a TIFF file type. This

is a lossless file type, meaning the image is not compressed so quality will not be compromised,

but it can lead to very large file sizes. When saving to TIFF in Photoshop, a number of

options are available. For beginners to the program, it is best to leave the options as they

appear. TIFF documents have a maximum file size of 4 gb.

BMP (Bitmap): This file type is a standard Windows image format, making it a multi-program

compatible format. Options when saving include converting the file to a different operating

system (to make the file ‘readable’ to non-DOS based computers). BMP documents have a

maximum file size of 2 gb.

PSD (Photoshop format): This is the default setting when saving in Photoshop. This is a useful

file type (along with TIFF) if your image is to be worked on, saved, and then worked on again

as no compression occurs. PSD documents have a maximum file size of 2 gb. Remember that

PSD files can only be opened in Adobe applications, such as Photoshop.


Printing your Image

Before you can print your image, you may need to resize it. As seen above, images opened in

Photoshop will normally have a ppi of 72, meaning a 6 mp image would be 99 x 74 cm (A4 paper

is 21 x 29 cm). Images can be resized using the Image Size option.

To open the image size dialogue box select:

Image > Image Size (Alt + Ctrl + I)

As most photographic paper below A4 size is sold in inches, it may be best to change the

document size measurements to inches using the down arrows next to the number boxes.

With the Resample Image box checked,

changing the document size width and

height would change the document size, but

retain the resolution. If we made the image

6” x 4”, then the resolution would remain at

72 ppi.

In order to retain image quality, uncheck the resample image box. This means that the image

will retain the 6 million pixels, but they will be squashed into a much smaller area, giving a new

ppi for the image of 1192.


When you have resized your image, select:

File > Print

Selecting the Page Setup option allows you to alter options in much the same way as other

Windows based programs, such as MSWord. You can change the paper size and its source in

the actual printer (if you have normal paper in tray 1 and photographic paper in tray 2, for

example).

Always make sure that the correct printer is selected in the Printer text box, at the top of

the dialogue box.

Once you are happy with all the settings, select print. This will open a printer dialogue box.

Click OK to print your image.

A second option when printing is to bypass resizing your image and merely selecting Scale to

fit Media in the print dialogue box. This will make the image fit into the paper size selected.


Printer Resolution

When printing, it is important not to confuse ppi with a printers’ dots per inch (dpi). While

your photograph is made up of individual pixels of one colour, a printer may have to produce

three dots of ink to show that one colour.

This example shows that in order to produce a pink pixel, the printer may

have to produce minute dots of red and yellow to create that same colour.

The dots produced by the printer are so minute as to convince the eye it is seeing an

individual colour.

This table shows a suggested available print size in relation to the actual image size when

using a 300 dpi ink-jet printer.

When you print, dividing the pixel size of the image by the available dpi will give a good

indication of the appropriate print size.

With a picture taken at 3 mp:

2048/300 x 1536/300 = 6.8x5.12 this means that a 7”x5” inch print could be produced.

Image Size Pixel Size Print Size (inches)

1 mega pixel 1280x960 pixels 6x4

2 mega pixels 1600x1200 pixels 7x5 / 6x4

3 mega pixels 2048x1536 pixels 10x8 / 7x5

6 mega pixels 2816x2120 pixels 10x8


Resizing your images Digital and Physical changes

There are many reasons you may want to change the size of your image, in both Pixel

Dimensions and Document Size.

We have already seen how the document size

of the image can be altered to prepare the

image to print on specific paper sizes. We

can also alter the image sizes to reduce the

file size of the image.

One of the main reasons for reducing the file

size is too allow ease of use when e-mailing

the image or posting it on the internet.

The first thing to do is create a duplicate of the image. This ensures that the original file is

untouched, remaining at the same size and quality. To do this:

Open the intended image

Select: File > Save As

Click the As a Copy check box in the save options area

Click Save

Close the image on screen and open the new copy of the image, to ensure you are working on

the correct copy. Examine the image and decide whether you can crop1 the image, which

reduces the image and file size immediately. Once you have cropped (or not) select:

Image > Image Size

1 If you crop the image, you may find that the image and file size are low enough to remove the need for

further resizing.


This will open the dialogue box shown above. By default Photoshop will open an image at 72

ppi. The megapixel amount the image was captured at will decide the Document Size. If shot

at 6 mp the image (before cropping) will be around 39 x 29 inches.

Changing the Document Size often reduces the file size, as the pixels in the image are

‘compressed’ to fit in to the new space. When altering Document Size remember to uncheck

Resample Image, or your image may end up containing only one hundred thousand pixels!

Save the image and the select File > Open. The original file and copy should be one after the

other in the file list. Hover the mouse cursor over the original and the copy to see the initial

change in file size.

The file size will not have changed by a great amount, but we can reduce this further by now

resampling the image. Again open the Image Size dialogue box and check the Resample box.

If you know the image will be printed by the person receiving it, 300 ppi should be the lowest

amount entered if you wish to retain quality (as much as possible). If the image will remain

‘digital’ then 150 ppi should be acceptable. Again save your image and check the new file size.

One further step we can take is in the JPEG compression of the image. It is assumed that

you have saved the image in this file type, as it is the most common and ‘readable’. Remember

that the higher the compression setting, the more the image quality will degrade and you run

the risk of compression artefacts appearing when the image is decompressed.

Remember to check your image as you work through reducing size, as you may find that

quality becomes too poor in the image. Also remember that you can undo changes to the

image size and select different sizes for each step as you go along.


Individual Panels

In this section we will look at the functions and use of the

individual panels used in this booklet


Navigator Panel

The navigator panel provides an easy way to move around an image. A thumbnail of the active

image is shown, with the proxy view area (red box) indicating what is being shown in the

active document window. The zoom text box shows the percentage of zoom currently in use;

this can be changed by highlighting the text with the mouse cursor and typing a new figure.

The zoom in and out buttons zoom incrementally and the zoom slider, used by dragging the

tab left or right, zooms the image in relation to the direction chosen. However the zoom is

implemented, the zoom text box will show the current percentage of zoom.

The hand icon visible in the proxy view area box can be used to move that box around the

thumbnail, moving the image in the active document window. Moving the mouse cursor outside

of the red box means a different area of the image can be selected and shown in the active

document window. The panel menu button allows you to change the proxy view area box

colour, through the panel options button.

Proxy View Area

Zoom Text Box

Zoom Out Button Zoom Slider Zoom In Button

Collapse Panel Button

Panel Menu Button


Histogram Panel

Exposure refers to the balance of shadows, midtones and highlights in your image. An

underexposed image will be overly dark and an overexposed image will be overly bright.

The histogram in Photoshop is a graph that shows this balance.

The histogram panel shows the tonal range of pixels in your image; the amount of pixels

making up shadows (left area), midtones (middle area) and highlights (right area). This is also

known as the image key type.

This histogram shape indicates a normal (correctly exposed)

image. (Average key)

This shape indicates an underexposed image, with the pixels

mainly grouped to the left of the graph. (Low key)

This shape indicates an overexposed image, with the pixels

mainly grouped to the right of the graph. (High Key)

Recognising these shapes means you can recognise ‘errors’ with your images before editing,

and so have an initial idea of how to correct that image.


History Panel

The history panel allows us to view every single action that we have performed on an image (up

to 1000 states, depending on file size, available memory, etc).

The topmost bar contains the original image and it will remain as such until the image is

closed. Every time the image is altered, a new state is added to the history panel. The most

recent state will be at the bottom of the list, highlighted in blue. From this we can compare

the original and altered image, delete the state thereby undoing that action or create a

snapshot/new document of that state.

To delete a state, select that state and then click on the rubbish bin icon at the bottom of

the panel window.

To create a new snapshot, select a state and then click on the camera icon at the bottom of

the panel window. This gives us a second image that we can compare with.

To create a new document, select a state or snapshot and click the active window icon at the

bottom of the panel window. This will open a new active window document showing that image.

The history brush source shows where information will be taken from if we use the history

brush found in the toolbox.

Set History

Brush source

History State

Delete current state Create new snapshot Create new document

from current state


Menu Commands

In the section we will look at alterations that can be made to an

image using functions found through the Menu Bar


Rotating an Image

Sometimes when taking a photograph, holding the

camera normally (landscape) means that the top of

the subject may be out of shot. To remedy this we

turn the camera through 90°, to take the picture in

portrait. When uploaded to a computer the image will

be accessed as landscape. To correct this, we can

rotate the image.

Select:

Image > Image Rotation > ?

selecting the amount and direction to

rotate. In this case, we want 90° CW

(Clockwise). CCW (Counter-Clockwise)

would put the building on its roof.

Rotating 180° would place the building

at the top left corner. Flipping the

canvas merely produces a mirror image

along the horizontal or vertical axis.

An image can be rotated at an angle other than 90° or 180°. If you select:

Image > Image Rotation > Arbitrary

this pop up will appear. You can type in whatever

angle you desire.


If you have an image where a horizontal or vertical is slightly ‘out of true’ but very difficult

to correct, you can use the ruler tool.

The ruler tool is found in the pop out menu of the eyedropper

tool, found in the toolbox.

Select the ruler tool and draw a line along the chosen

horizontal or vertical axis in your image.

If you now select:

Image > Image Rotation > Arbitrary

you will find that a value has already been entered for

the angle amount.

Select ‘OK’ and the image will rotate. It may take a few tries to get the angle completely

correct, but it does improve on taking a wild stab at the angle needed in the arbitrary pop up.

If the rotation does not look correct, you can always select:

Edit > Undo Rotate Canvas

Now that the canvas has been rotated out of a right-angled

position, we will have to crop the image.


Cropping an Image

Cropping an image is relatively simple. All we have to do is select the crop tool from the

toolbox and select an area of the image to crop.

Select the crop tool and

position it at the top left

corner of your proposed

selection. Press and hold the

left mouse button and drag the

mouse cursor diagonally to the

bottom right corner. When

you are done, release the

mouse button and a Bounding

Box will appear. The area

outside of the box will be

shaded, highlighting your

selection.

The box can be altered by selecting and dragging the handles at the corners and mid-section

of the box. Pressing the ‘Esc’ key at any point will remove the bounding box. Once you are

happy with the selection;

Click the tick in the options tool bar

Press ‘Enter’ to crop the image

Double click inside the bounding box

It is important to remember that a cropped image is smaller than the original. If you started

with an image to print at 6”x4”, the cropped image may not be of a high enough resolution to

produce a good quality 6”x4” print.


Exposure correction

The levels dialogue box, opened through Image > Adjustments > Levels (Ctrl+L), gives you

control over the pixels in the three main areas; shadows, midtones and highlights.

To adjust an underexposed image, move the highlight slider to the left. For an overexposed

image, move the shadow slider to the right. The midtone slider can be used to ‘fine tune’ an

adjustment, moving left for underexposed and right for overexposed images, but it can

affect the image contrast, making an image seem dull. Always have the Preview box checked,

so that you can observe changes being made in the image.

Having made changes to the image, look to the histogram panel and click on the exclamation

symbol (Cached Data Warning icon). This will update the histogram, showing the new

graph.

These gaps and spikes in the graph shows a loss of tonal

detail in shadows, midtones and highlights; a result of

working on the image.

Input Shadow Slider

Midtone Slider

Highlight Slider


Contrast correction

This histogram graph shows an image low in contrast. To

correct this, move both the shadow and highlight sliders in

towards the base of the main ‘body’ of the graph.

This histogram graph shows an image with high contrast.

This cannot be greatly affected with the input sliders.

Instead, move the output shadows and highlights sliders.

Moving these sliders will change the intensity of

shadows and highlights, making them a lower tonal

value.

Output Shadow Slider Highlight Slider


Colour balance and casts

A colour cast is when an image appears to have a veneer of one colour covering that image.

Normally your digital camera will be unaffected by casts, selecting the correct white balance

for an image. Casts can occur in extremely difficult lighting situations or when one colour is

overly present in the image.

There are a number of ways of correcting a colour cast:

Selecting auto colour makes the program try to correct the colour cast automatically. This

produces correct results much of the time, but is not always good enough. Always try this

option first as, if successful, it will remove work for you.

Auto Colour

Colour Balance

Variations


Selecting variations opens a dialogue box showing the possible colour changes available.

The top two thumbnails show

the original image (left) and

the current changes applied

(right). The six thumbnails

surrounding the central

‘Current Pick’ image show what

changes will occur when more

of one colour is added. Look at

these images to select the

correct change. You may find

that you have to adjust the

Fine/Coarse slider if you

cannot find the correction you need. The three thumbnails to the right allow you to change

the image brightness. Click on the appropriate thumbnails to achieve the desired result and

once you are happy, click OK to apply those changes.

The colour balance

window is for more

experienced Photoshop

users. Firstly you will

have to recognise what

cast is affecting your

image, then change the

individual colour sliders to

correct it.

When using variations or colour balance to correct colour casts, always make sure that

midtones is checked.


Hue and Saturation

Sometimes when we take a photograph, the resultant image looks bland and colourless. This

can be for a variety of reasons, the most common being poor lighting conditions. For example,

if you take a photograph outside on a cold, wet, overcast day, the colours in the photograph

may not be as vibrant as expected.

With the hue and saturation dialogue box, the

colour (Hue), intensity (Saturation) and Lightness

can be altered to change the overall look of the

photograph.

Open the Hue/Saturation dialogue box by selecting:

Image > Adjustments > Hue/Saturation

(Ctrl + U)

As you move the hue slider left or right, the number in the

text box represents the degrees around the colour wheel

(see left) that pixel has moved. Sliding right moves the

colours clockwise (+), sliding left moves the colours counter

clockwise (-).

As you move the saturation slider left or right, the colour

intensity increases or decreases. Left makes colours duller,

moving to the edge of the colour wheel. Right makes the

colours more intense, moving toward the centre of the

wheel.

As you move the lightness slider right, more white is added to the selected colour,

brightening that colour. As you move left, more black is added to the colour, darkening that

colour.

Image taken from Adobe Help Centre


Editing specific colours

In the Master pull-down window, you can select a number of preset colours to change.

Selecting Master makes the change in hue, saturation or lightness affect

the entire image. If you want to change one colour, you can select it from

pull-down menu.

Selecting an individual colour makes

additional options available.

Having selected Reds, only pixels of

that colour in the image will be

affected. The adjustment slider

resides in the red section in both colour

bars. If the hue slider is changed, that

change will be shown in the adjustments

colour bar, beneath the dark grey

section of the adjustment slider.

The eyedropper tools can be used to select colour from an image, increase the number of

colours within a selection or decrease the number of colours.

When using the hue/saturation dialogue box, always have the preview box checked, so you can

observe changes in the picture. If the change is too much, you can reset the sliders by

pressing the Alt key on the keyboard. This changes the Cancel option to Reset. With Alt

held, click reset.

Reference

Colour Bar

Adjustment

Slider

Adjustments

Colour Bar


The Unsharp Mask

The Unsharp Mask is used to sharpen images. This is a filter, found in:

Filter > Sharpen > Unsharp Mask

This opens the Unsharp mask dialogue box. A preview window of the image can be seen, but it

is best to observe changes to the actual image; make sure that the preview box is checked

and the dialogue box does not obscure your view of the active document window.

The preview window can be zoomed in and

out, allowing you to observe the whole (in

the active document window) and part (in

the preview window) of the image at the

same time. You can move around a zoomed

preview window by placing the mouse cursor

in the window; it will become a hand icon.

Press and hold the left mouse button and

‘scroll’ around the image. While the mouse

button is pressed, the effects of the

unsharp mask are not shown in the preview

window.

The unsharp mask filter works by increasing the contrast along edges of an image. These

edges are ‘found’ by comparing pixels with adjoining pixels; pixels with contrast between them

will form an edge (edge pixels). The filter increases the contrast between edge pixels; light

pixels get lighter, dark pixels get darker.


Amount Slider

The edge pixels are changed by the percentage set with the amount slider. The amount

available is between 1 and 500%. At very high amounts, you may find that a ‘halo’ appears

around objects, showing that the image has been oversharpened.

Radius Slider

The radius selects the amount of pixels surrounding the edge pixels to be altered. As the

radius increases, these edges will become more apparent as more pixels fall within the

affected area.

Threshold Slider

The threshold slider determines how much contrast needs to be present in the edge pixels

for the filter to affect them. The tonal value* of each pixel will be looked at. If the

threshold is set to 10, then only pixels with a difference in tone of 10 or more will be

affected. If a pixel with a value of 120 is next to a pixel of 129 they will not be affected, as

they are within the threshold level; they are not of enough contrast to warrant ‘sharpening’.

Original image Unsharp mask used; Amount: 200

Radius: 2

Threshold: 5

An image with an obvious ‘halo’


Suggested settings for different images

Amount

The amount set is dependant upon the image to be altered, as this can be different for each

image. It is important to remember that as the amount gets higher, the contrast between

edge pixels will become more apparent. It is suggested to start with an amount of 100%,

increasing or decreasing the amount as required/desired.

Radius

As digital cameras and scanners vary in the pixel dimensions they can capture, so too does the

level of radius images can ‘withstand’.

Pixel dimension Suggested radius

0.5 – 3 mp 1

3 – 5 mp 2

6 + mp 3 - 4

The amount and radius sliders are interdependent. As one is raised so the other should lower,

to keep an image realistic.

Threshold

As the threshold setting defines the amount of pixels included in the sharpening process, it is

important to recognise when, and how much, to select. If an image contains a large amount of

continuous tone, such as a portrait, it is best to set a relatively high threshold of about 10.

If the image is a landscape, with soft flowing edges, the threshold should be higher. For

images of buildings or specific objects, a lower threshold can be set.

The amount of sharpening needed depends on the intended output of the final image. A high-

resolution image can appear excessively sharp on screen, but when printed this effect may be

muted. It is always best (although possibly expensive) to find a base level for the printer you

intend to use. You may also find that the increase in contrast has oversaturated your image.


To combat this select: Edit > Fade Unsharp Mask; choosing Luminosity from the Mode

menu.

Remember that the final decision in matters like this is in the eye of the beholder! If you

find a particular alteration pleasing, then go with it. As long as you always use the preview

before confirming the selected alteration, nothing should go wrong.

When you are happy with the overall result click ‘OK’ to confirm and complete the sharpening

process.

* The tonal value of a pixel is its colour in numbers. The histogram shows tonal value against

number of pixels; pure black is 0 and pure white is 255.

With the threshold set to 10, if a pixel of 170

is next to a pixel of 173 it will not be

affected. If the 170 pixel is next to a pixel of

70, they will both be affected.


Adjusting the Perspective

Keystone Distortion occurs when a photograph is taken at an angle, instead of straight-on.

This frequently occurs when photographing tall buildings from ground level. In order to

capture the whole building, the camera is held at an angle; in the resultant image, the building

will appear to taper in at the top.

This tapering can be adjusted using the Transform tools in

Photoshop.

When adjusting image perspective, it

is best to leave images in the default

opening setting, so that it is wholly

visible and easy to work with.

If you can see that your image suffers from keystone distortion, but find it hard to judge

straight verticals, you can ‘place’ a grid over the image to help. Select:

View > Show > Grid (Ctrl + ‘)

The grid can be turned off in the same way. The grid is most

helpful when dealing with obvious straight vertical lines in

images that are slightly ‘out of true’.

You may find that the grid lines are too close

together. If this is the case, select:

Edit > Preferences > Guides, Grid & Slices…

Changing the ‘Grid every:’ and ‘Subdivisions:’ can

make the grid more easy to see.


In order to affect your image, it must be selected. This can be done by selecting:

Select > All (Ctrl + A)

Now the ‘marching ants’ are surrounding the whole

image. Select:

Edit > Transform > Perspective

This will place a bounding box with handles around

the image.

Positioning the mouse cursor over a handle at the

corner will make it light grey, midpoint cursors are

light grey with a double ended arrow showing the

direction of movement. Press and hold the left

mouse button and move the mouse. The image will

copy that movement.

At beginner level, always make sure that the reference point locator is set to the centre of

the image and always use the handles to change image perspective.

When you are happy with the results, either;

click the commit button;

press ‘Enter’

double-click within the bounding box

To cancel the transformation, either click the cancel button or press

‘Esc’ on the keyboard. To deselect the image, select:

Select > Deselect (Ctrl + D)

The marching ants will disappear. After altering perspective, you may

have to crop the image.


Free Transforming

Free Transform allows us to edit an image or selection in the same way as selecting:

Edit > Transform > ?Selection?

If more than one transformation is being applied to an

image, it is best to apply them all at the same time. Each

separate transformation applied to an image will lessen its

overall ‘look’, with loss in sharpness and resolution.

Applying a cumulative transformation (two or more at once)

will lessen this negative impact.

With the free transform bounding box, we can apply all of the available transformations;

scale; rotate; skew; distort; perspective; warp; without having to continuously select:

Edit > Transform > ?Selection?.

Free transform can be initiated by:

Selecting Edit > Free Transform

Pressing ‘Ctrl + T’ on the keyboard

Clicking the right mouse button and selecting Free Transform from the pop up menu

To use the transform options an area has to be actively selected or not ‘Locked’, indicated by

a padlock symbol in the layers panel.


Transformation Free Transformation Key

Scale (with handles)

Position the mouse cursor over a handle.

Press and hold the left mouse button while

dragging the mouse. To maintain aspect ratio,

hold shift while dragging a corner handle.

Scale (numerically)

Enter a percentage figure into the width and

height boxes in the options toolbar. To

maintain the aspect ratio, click the Link symbol.

Rotate (dragging)

Position the mouse cursor outside the

bounding box. It will become a curved

double-ended arrow. Press and hold the left

mouse button to rotate around the reference point location.

Rotate (numerically) Enter a degree figure in the rotation text

box in the options toolbar.

Distort (relative to the centre of the image) Press and hold ‘Ctrl’ + ‘Alt’ while dragging a

handle.

Distort (freely) Press and hold ‘Ctrl’ while dragging a handle.

Skew Press and hold ‘Ctrl + Shift’. The cursor will

change at side handles Drag a side handle.

Skew (numerically) Enter a degree figure into the ‘H’ or ‘V’ text

boxes in the options toolbar.

Perspective Press and hold ‘Shift + Ctrl + Alt’. Drag a

corner handle.

Warp Click the ‘Switch Between Free Transform

And Warp Modes’ button.

Change reference point

Either; select a new point by clicking the

appropriate box in the reference point

locator or press and hold the symbol and

move it manually.

To commit the selected transformations; double click within the bounding box; press ‘Enter’;

click the tick symbol in the options toolbar. To cancel the selected transformations;

press ‘Esc’; click the cancel button in the options toolbar.


Using the Toolbox

In this section we shall look at various tools found within the

toolbox, and how to use them to alter images


Dodge and Burn Tools

The dodge and burn tools are used to lighten and darken areas of an image respectively. They

are held, along with the sponge tool, in the same area in the toolbox; swapping between them

means right-clicking the tool icon to open the pop-up menu.

These tools are used as brushes, so options on their settings can be

controlled by the options toolbar.

The tool icon shows the

current tool being used. The

brush size is the pixel

diameter of the brush.

Range indicates which pixels

will be affected, in this case,

midtones. Exposure relates to

the intensity of the dodge or burn tools. A low exposure means light and dark are changed in

relatively minor amounts each time you click the mouse button. A high exposure means

changes will be much more apparent with each mouse click. Selecting the Airbrush tool means

keeping the mouse button depressed continues to dodge or burn the image. Without the

airbrush option selected, the mouse button must be continuously pressed to achieve results.

Clicking the down arrow in the brush size box

opens a pop-up menu. Here the diameter of the

brush can be changed, as well as the hardness.

Hardness of the brush refers to the amount of

anti-aliasing of that brush. Anti-aliasing

means the brush will partially fill the edge

pixels with the background colour.

This means that instead of the brush producing


a solid block of difference, at a low hardness the edges of the brush will form gaps filled by

the background.

This example shows the extreme difference

between 0 and 100% hardness.

Even at 100% the brush is still anti-aliased, but

it is barely noticeable.

The square bracket keys on the keyboard reduce ([) and increase (]) the brush diameter;

holding the ‘shift’ key while pressing the bracket keys will change the brush hardness.

Preset brushes are brushes set to different diameters and hardness, set out in order of size,

to ease brush selection. While you can change preset brush attributes, they will revert to

the original setting when that brush is selected again.

Clicking the menu button will make the pop-up menu appear. From this you can choose a

great number of different brushes available. However, as a beginner, it is best to

practise with the basic brushes, until you feel more confident.

When using the dodge or burn tool, it is best to start with a low exposure and build up

changes to the effect you are looking for.


The sponge tool

The sponge tool is used to alter the saturation of colour within an image. Two modes can be

chosen, saturate or desaturate. Saturate means that the colour intensity will be increased,

Desaturate means the colour intensity will be lessened. Flow, much like exposure in the

dodge/burn options bar, indicates the intensity of the change this brings about. A small flow

percentage will produce small changes; a large flow percentage will increase the brush

effectiveness. Again the airbrush option is available, making the brush work in the same way

as it does the dodge/burn brush.

All brush tools can be hard to master, so it is good to remember that you can undo your

previous actions. With that in mind it is best to use the brush tools in short ‘bursts’. For

example, brightening a large and difficult area in one go, then making a mistake at the end,

can mean having to redo that whole section of work. This can be very disheartening!


Cloning

The clone stamp tool is used to ‘copy’ one area of an image into a different area. This can be

in the same image or a different one. The tool does this by sampling an area of the image and

painting it into the selected area. Cloning is often used to obscure areas of an image that

detract from the whole.

The clone tool works as a brush, so the size (in pixel diameter) and the hardness can be

selected from the options toolbar. When cloning, a soft edged brush is often preferable, so

as to blend in the cloned area with the background. Mode, opacity and flow are best left at

the default settings (Normal, 100%, 100%) when a beginner to the program, but can be

explored when confidence has grown.

The Aligned checkbox shows whether the sample point will move with the cloned area or

remain in the sampling area.

Aligned checked: The sample point stays at the same distance and position to the brush

(mouse cursor)

Aligned unchecked: The sample point reverts to the original area if the mouse button is

released then pressed

In this example, we see that the brush used to

obscure the middle of the ball was soft edged.

This adds to the effect, as areas of the

background will blend in with the edges of the

clone area.

When cloning, it is important to select a sample area that will ‘work’ with the chosen clone

area; they should have a passing resemblance in subject, hue and brightness, so that the clone

area is not obvious.


Area Selection: Marquee Tools

The Marquee tools are used to select specific areas

within an image that need to be worked on.

Rectangular: Creates a rectangle around an area

Elliptical: Creates an ellipse (circle) around an area

Single Row: Creates a 1 pixel thick selection across the entire image

Single Column: Creates a 1 pixel thick selection down the entire image

Pressing and holding ‘Shift’ while selecting with the rectangle and ellipse tools will form a

perfect square or circle. Keep shift depressed until you release the left mouse button.

Selecting an area:

Place the mouse cursor at a corner of the intended area; press and hold the left mouse

button; drag the cursor over the intended area.

Place the mouse cursor in the centre of the intended area; press and hold the ‘Alt’ key;

simultaneously press and hold the left mouse button; drag the cursor out to the edges of

the intended area. (Can only be used for initial selection)

The selection will be shown with a marching ants line.

Once an area has been selected, work on the image can only be performed within that area.


Options toolbar for the marquee tools

The left most icon shows which marquee tool has been selected. In this case, the rectangular

tool is selected.

Selection Options

New selection: The marquee tool can only create one selection area. Selecting a new

area will cancel out one already created.

Add to selection: More than one selection area can be created in one image. They

can be independent selection areas anywhere within the image. If two or more

selection areas touch or overlap, they will join to form one selection area.

Subtract from selection: Having created one selection area, additional selections

overlapping the first will result in the overlap area being deselected. Selections

attempted not touching the first selection will not be created.

Intersect with selection: Having created one selection area, subsequent selections

that overlap the initial area will result in the overlap forming the selection area.

These options can be selected from the options toolbar before or during selection area

creation.

Keyboard shortcuts can be used once the initial selection has been made:

Press and hold ‘Shift’ for ‘add to selection’

Press and hold ‘Alt’ for ‘subtract from selection’.

Press and hold ‘Shift + Alt’ for ‘intersect with selection’.


The Feather option allows you to select how ‘sharp’ the selection

area will be. 0 pixels (px) means the edges of the selection area will be pixel sharp. As the

feathering amount goes up (to a limit of 250 px), the edges of the selection will become more

blurred. Detail in the image can be lost as feathering is increased.

The Anti-alias option, only available with the elliptical marquee tool, smoothes edges of

selection areas. No detail in the image is lost through anti-aliasing. Anti-aliasing can only be

applied before the selection is made.

Style

Normal: Selection must be made by dragging the mouse cursor over the image.

Fixed Aspect Ratio: The selection created will conform to the width to height ration entered

into the appropriate boxes. For example, to have a rectangle twice as long as it is high, enter

2 into the width box and 1 into the height box.

Fixed size: The selection area is entered into the width and height boxes. Clicking the mouse

cursor over the image will produce an area conforming to the amount, entered in pixels, in the

boxes. Knowing the ppi of the image is helpful here; to create a square inch selection area in

a 72 ppi image, 72 px would be entered in both the height and width boxes.

A selection area can be increase or reduced by selecting:

Select > Modify > Expand/Contract

The amount required being entered in pixels.


The marquee can be moved before selection is completed. With the left mouse button still

depressed, press and hold the ‘space bar’. Moving the mouse cursor will now reposition the

marquee. Releasing the space bar will mean the selection area can again be changed.

To move the marquee once selection is complete, position the mouse cursor within the box.

Press and hold the left mouse button and drag the marquee to the new position.

To deselect an area when you have finished with the selection, either click the right mouse

button and select ‘Deselect’ from the pop-up menu, select: Select > Deselect (Ctrl + D) from

the menu bar or, if using the ‘new selection’ option, left click anywhere in the image (outside

the marquee).

If you find you have deselected an area by mistake, you can reselect the area by selecting:

Select > Reselect (Shift + Ctrl + D)

It is often easiest to select an area by selecting an area to be left unaltered and inverting

that selection; choosing the area we do not want changed and then selecting everything but

that area.

To invert a selection, select:

Select > Inverse (Shift + Ctrl + I)


Area Selection: Magic Wand Tool

The selection options buttons perform the same functions with the Magic Wand tool as with

the marquee tools. The magic wand is used by clicking the left mouse button over an area to

be selected.

Tolerance: This indicates what similarity needs to be present for pixels to be selected. The

amount can be from 0 to 255, entered in pixels. This tolerance means how much of a

similarity must be present in pixels, compared to the pixel that was first selected. A low

number means the pixels must be very ‘like’. As numbers get higher, pixel similarity

diminishes.

Anti-aliasing: Again this refers to the smoothness of the edge pixels between those

selected and those not.

Contiguous: If this box is checked, the tool will only select areas of colour adjacent to that

selected. If unchecked, the whole image will be scanned and pixels falling into the selection

criteria (tolerance) will be selected.

A selection made can be increased by selecting: Select > Grow

Areas of similar colour can be selected by selecting: Select > Similar


Options common to selection tools

Having made a selection:

Pressing ‘Delete’ or ‘Backspace’ on the keyboard will replace the selection area with the

Background colour, deleting the selection

Cutting the area with Edit > Cut (Ctrl + X) will remove that area to the clipboard,

replacing the area with the background colour

Copying the area with Edit > Copy (Ctrl + C) will copy that area to the clipboard without

removing the selection

Clipboard contents can be pasted with Edit > Paste (Ctrl + V) into the same image or into

a different image

Using the Move tool when an area is selected means it can be moved within the image, or

drag & dropped into a different image. When moving selections within the image, the

background colour replaces the selection area.

Mouse Cursors

Standard marquee cursor

‘Add’ selection cursor

‘Subtract’ selection cursor

‘Intersect’ selection cursor

‘Cut’ cursor

‘Move’ cursor

Magic Wand cursor; +, - and x are added to the cursor as they are selected


Area Selection: Lasso Tools

The lasso tools are used to make freehand selections. This is perhaps one of the most taxing

selection tools, as it relies on your ‘mouse skill’ to make the required selection. Once an area

has been selected, it can be edited in exactly the same way as with other selection tools. The

three variations, Lasso, Polygonal Lasso and Magnetic Lasso each behave in slightly

different ways.

Lasso Tool

As you can see from the options toolbar, there

are not many changes we can make to the basic

settings. As with other selection tools, the selection options allow us to; ‘add new’, ‘subtract’

and ‘intersect’ selection areas; set the ‘feather’ amount; check ‘anti-alias’.

It can be very hard to draw a perfect line around the intended area; not only is a bulky mouse

being used, we also have to keep the left mouse button depressed.

One way to rescue a faulty selection is to Transform Selection. Select:

Select > Transform Selection

This forms a bounding box about the marching ants line.

You can now edit the selection border without affecting

the selected area.

This option can be used with all other selection tools.


Polygonal Lasso Tool

This tool makes a selection without the left

mouse button being constantly depressed. The button is clicked

at the start of the selection border and clicked again when that

‘segment’ is complete. The border will continue until the next

click of the mouse button, finishing another segment. This

continues until the start and end segments meet. The tool

creates a straight edged line. Incorrect segments can be

deleted by pressing the delete key before the line is complete.

Magnetic Lasso Tool

This tool works by laying down a border which follows the mouse cursor, selecting contrast

around the cursors’ path.

Width controls the size of the area that finds the ‘edges’, to which the border is attached.

Edge Contrast (from 1% to 100%) determines how contrasting pixels must be. A high value

means edge pixels must be very unlike surrounding pixels, a low value means edge pixels can be

less contrasting.

Frequency (from 1 to 100) denotes the speed at which ‘anchor points’ will

be set. As the number increases, anchor points are created more quickly.

As with the polygonal lasso, incorrect anchor points can be deleted

before the border is complete. If the border will not fasten where you

wish, anchor points can be created by pressing the left mouse button.


Moving your Selection

As has already been discussed, there are a number of ways of moving a selection:

Copy and Paste – The selection area is copied to the clipboard and can

be pasted into the same/a different image as a new layer. This layer

can be moved freely with the move tool.

Cut and Paste – As with copy and paste, the image is sent to the

clipboard and can be pasted into the same/a new image as a new layer.

The selection area is cut from the initial position and replaced with

the background colour.

Cut-Move – This can be done with either the move tool or, as there is

a current selection, almost any tool while ‘Ctrl’ is depressed on the

keyboard (e.g. the Brush tool). This cuts the selection from the image

and allows you to move it freely within the image. If the selection

remains in the start image, the original area is replaced with the background colour. If it

is moved into a second image (drag and drop) the initial selection returns to its start point.

Copy-Move – Again this can be done with either the move tool or almost

any tool (as long as there is a selection present). Using the move tool,

depress the ‘Alt’ key and move the selection. The original will remain in

position while a copy will move with the mouse cursor. With other tools,

press ‘Ctrl + Alt’ to use copy-move. Cut- and Copy-move do not create new layers.

The ‘Show Transform Controls’ checkbox in the move tool options toolbar allows you to access

the Free Transform options by clicking the bounding box shown.


Quick mask mode

Quick mask mode can be used to select areas in an image or to adjust areas

already selected. It is entered by clicking the toggle switch, one up from the

bottom of the toolbox. Quick mask mode is exited by again clicking the toggle switch

The mask is represented by a colour; default is red at 50% opacity, which covers the specific

area designated in the ‘Quick Mask Options’ dialogue box. These settings can be altered.

When colour indicates ‘Masked Areas’; entering

quick mask mode with an active selection border

will mean everything outside that border will be

coloured red (default).

Active marquee selection Resultant quick mask mode

If ‘Selected Areas’ is checked, the selection area will be coloured and the masked area

(outside the active selection) will appear normal.

Quick mask mode works in greyscale, which means that painting with a brush tool in black will

add the chosen colour and painting in white will delete the colour. Any colours chosen other

than pure black or white will be displayed as varying shades of grey in the fore- and

background colour boxes. Painting with grey makes a more transparent colour appear. This

can be used to feather or anti-alias the selection.


Selecting an area with quick mask mode

Double click the quick mask mode button and check ‘Selected Areas’. This means that painting

onto the area you want selected will, when you revert to standard mode, form a selection

border around that area. With this option it is best to also make sure the mask colour is

highly distinguishable from areas in the image. For example, editing a red post box beside

another red post box, standing in front of a red post office van, could be quite hard with the

mask shown as red!

Once you have painted over the chosen area, revert back to standard

mode. A marching ants line will show around the borders of the area you

painted.

If you find, in standard mode, that you have missed some areas or gone ‘over the lines’, go

back to quick mask mode and edit your selection. Painting in black will add to the area;

painting in white will remove areas.

Editing a selection with quick mask mode

In this instance, it is easiest to work with the colour covering ‘Masked Areas’, as this means

areas you do not want altered will be ‘coloured in’. Again, painting in black will add colour and

white will remove it. Remember this means the opposite to checking ‘Selected Areas’. Now

adding colour will remove that area from the selection and removing colour will add to the

selection, on reverting to standard mode. This technique can be very useful

when dealing with areas hard to select. As you can use brushes to add to or

remove areas of the selection, you can have a much larger tool-head to work

with, easing the selection process.


Paste into

Paste Into is used in much the same way as normal pasting within a computer program; an area

is selected and copied or cut, storing this piece of data on the clipboard. The second image,

or destination, is then made active and the data from the clipboard pasted onto same. With

normal cut/copy and pasting, this would result in the pasted data appearing in the centre of

the destination image and obscuring whatever area it is covering.

Paste into overcomes this problem by literally pasting the data into a selection area created in

the destination image.

Pasting this cloudscape on to the destination

image would result in covering the entire image, as

they are the same pixel amount. You could

overcome this problem by erasing part of the

clouds, but this would be a tricky, taxing and overly long process.

Selecting the sky will mean that copying and pasting the cloudscape

into the destination image will confine the image to that area.

The cloudscape can be moved and resized freely as it

appears as a new layer within the image.

The layers panel shows the destination file as a background

layer. The new layer, layer 1, shows a thumbnail of the

image and also a layer mask thumbnail. This mask works in

the same way as the quick mask; selecting the thumbnail and

drawing on it in black will obscure areas of layer 1; drawing

on it in white will reveal areas of layer 1.


Adding Text to an Image

To add text to an image, select the text tool from the toolbox and position the mouse cursor

at the point where you want text to appear.

This is the cursor for the text tool. Clicking anywhere in the image will create an

insertion point, as seen in text based programs, such as MSWord.

The text baseline is the line

the text follows and is not seen

after text is committed.

Text can be written on a horizontal or vertical axis,

depending on the tool chosen. Text masks create

selection areas that can be affected just like other

selections.

Text is created as a new layer and can be edited, before or after typing, when that layer is

selected in the layers panel; the text mask tool will create a selection on the active layer.

The text mask is best used on an image layer, as opposed to a text layer.

As with text applications, the font type, style, size, colour and ‘look’ can be affected with the

text options toolbar. Text can be highlighted in the same way as text applications (making

sure the text layer is selected) or by double-clicking the text icon in the layers panel.

To commit a text entry, click the tick symbol in the options toolbar; press enter on the

number pad; press ‘Ctrl + Enter’ on the keypad.

Insertion point


Text Orientation: Text can be set to a horizontal/vertical plane before or after it is

written

Text Font: Allows you to change the text font, giving examples of the text font beside its

name

Font Style: Allows you to alter the style to Bold, Italic, or Bold Italic

Font Size: Allows you to change font size. The size of the image will affect the viewing of

the text. With text applications, the text size is set to be viewed on an A4 sheet of paper.

Text size in the pull down menu in Photoshop is set to that same sizing.

This is a 6 mp image, making it 99.34 cm wide and

74.79 cm high. As you can see, a text size of 24 pt

(point: 1 point is equal to 1/72 of an inch in a 72 ppi

image) is too small to read. If the image is resized to

25x19 cm (10x8”), then 24 pt becomes viewable.

Anti-alias: Sets the smoothness of text edges

Text Colour: Allows you to change text colour

Text Warp: Text warp allows you to alter text in much the same way as WordArt in

MSWord.

Effects can be added

at any time, as long as

you select the correct layer in the layers panel. Effects chosen can be

altered in the Warp Text dialogue box.


Additional Notes