PhotoShop Elements2 (PsE2)

1
PhotoShop Elements2 (PsE2)

• Image manipulation programs
• Digital photographs
• File types and sizes
• File compression
• File manipulation
• Manipulating figures with PsE2
• Sizing and Compressing Figures
• Enhancing Figures
• Adding Labels to Figures
• Compressing Figures
• Using Layers

2
PhotoShop Elements2 (PsE2)

• This presentation and all the others can be found
  via a special menu linked to the default MSc
  tutorial home page
• Address for this is
• http//www.kcl.ac.uk/kis/schools/life_sciences/lif
  e_sci/msc/Summary2002.html

3
File sizes

• You should always try and reduce file sizes while
  retaining enough quality in the final image
• The size of image file will be in Kb (kilobytes)
  or Mb (megabytes)
• Having too high a resolution is pointless in
  PowerPoint or Word
• Try and reduce the size of all files - compress
  - as small as possible
• Rule of thumb 100Kb is usually OK
• but smaller is better!

4
Sizing figures in Word-Revision!

• Import (or paste) picture
• Right click on the image
• Click on Format Picture
• Click on Size tab
• make sure that lock aspect ratio and relative
  to original size are ticked unless you are sure
  you want to alter these
• You can then size either in units (inches or cms)
  or in age and position on the page
• for a full A4 page, maximum width should be 7
  (say 18cm)
• usually better smaller
• you can then adjust the wrapping of text around
  the figure

5
Inserting Media

• For all media try and keep the file size as small
  as possible consistent with clarity
• Remember 1Gb 1000Mb 1,000,000Kb
• (Floppy disc 1.4Mb) CD 640Mb memory sticks
  up to say 1Gb (max now 8Gb!) DVD 4.8Gb (single
  layer) mp3 players - up to 60Gb(?)
• Despite the increase in available space you
  should still keep size to lt50Kb per slide image
• Even if you have a large USB memory stick, the
  smaller the individual files the better!
• If you want to print an image gt2Mb is usually
  waste

6
Picture Formats

• There are a whole range of different ways of
  presenting figures, but the commonest include
• TIFF
• very often the standard output from scanners
• can be partly compressed
• still tend to produce quite large files
• JPEG
• often the standard output from digital cameras,
  variable compression levels.
• At high compression settings colours tend to
  bleed medium size
• GIF
• highly compressed - used for web images
• limited colour representation

7
Two Images - Can you see a real difference?

• Left picture, 62Kb
• as JPEG file

• Right picture, 4.2Mb
• as TIFF file

8
Photo Manipulation Software

• To change between the different formats (and file
  extensions) we need specialist image processing
  software packages. These include
• Adobe PhotoShop
• Industry standard, very expensive not on PAWS
• Paintshop Pro
• Almost all features of PhotoShop but 1/4 the
  price also not on PAWS
• PhotoShop Elements
• Available on PAWS as Version 2
• Version 4 is current High Street form
• Retains most useful features of PhotoShop at
  1/10 of cost (60 versus 600)

9
Vector versus Bit Mapped Graphics

• Vector graphics
• For simple (and more complex) diagrams
• Drawing packages
• e.g. Adobe Illustrator, Corel Draw, Word Draw
• saves vectors e.g. the lengths and directions
  of drawn lines
• Compact files
• Time consuming!
• Gives high quality artwork (with practice)
• Smooth shapes at all magnifications

10
Vector and Bit Mapped Graphics

• Bit mapped graphics
• Such as photos - pixels
• Relatively large files
• Using a scanner or digital camera can be quite
  fast
• Gives rough outlines jaggies if over enlarged
• Lab projects
• You can use a scanner or a digital camera to get
  instrument traces or gel images into digital form

11
Vector Graphics
Ideal for diagrams and line figures
12
Bitmapped Graphics
Photos and scanned figures
13
Using PhotoShop Elements (PsE)

• First locate PsE on tool bar
• Logo looks like a sunflower
• Open it up but ignore the many messages
• Select a picture to edit using the file browser
• If you do not have one in your own file space,
  look on the web!
• To find images use Google Image Search

14
Using PsE 2

• Try saving the file in different formats
• (use Save As) and compare the size of the file
• file types include tiff, jpeg, psd, etc.
• Image manipulation includes
• reducing the visible size (cropping)
• adjusting the contrast, and colours
• changing the colours e.g. to black and white
• sharpening the image
• repairing blemishes and restoring appearance

15
Using PsE 3 - Tool Box Palette

• The toolbox has a variety of useful tools
• Crop
• Brush (recolouring)
• Paint Bucket (ditto)
• Eraser
• Gradient
• Type
• (text as box or paragraph)
• Pencil (drawing)
• Zoom

16
Using PsE 4

• Layers
• PsE uses layers which are like having a series
  of overhead transparencies on top of one another
• these layers can be manipulated separately
• useful but difficult and needs practice
• Text (or typing) uses layers
• saving in some formats merges down layers
• gives compact files, but text is no longer
  editable

17
Enhancing an image

• Quick Fix
• Try it and see!
• Auto Contrast and Auto Levels
• Can make flat images look much better
• Variations
• Show effects of possible adjustments
• Good for removing colour casts (as is Color
  cast)
• Filters
• Allow fancy effects e.g. sunrise etc.
• Sharpen filters can help a lot

18
Enhancing an image2

• Can convert colour to black and white or gray
  scale
• Can be useful for colour diagrams for publication
• You pay extra to publish with colour!
• Changes can benefit from tight cropping first!
• Resizing also an option

19
Cropping an image

• Removes unnecessary detail
• Allows eye to concentrate on most important
  features
• Removes white space
• Can change say rectangular to square or crop to
  particular ratio of dimensions
• 35 mm film (remember this?) has image size of 36
  x 24 mm (i.e. ratio is 32)
• Digital camera images are typically 43 ratio
• e.g. 2816 x 2112 pixels for a modern 6Mpix
  camera)
• But photo paper is still 32 (e.g. 6 by 4)
• Cropping yourself is better than letting Boots do
  it for you!

20
Labelling a Picture

• Enables you to write text labels on a picture
• Add arrows or scale bars
• Change font
• Labels work on layers
• Like having the text on a different sheet of film
  to the image

21
Layers

• Merging layers down
• After merging down you can no longer edit a type
  layer
• You can also apply adjustments e.g. contrast
  changes in layers
• just delete the layer if you do not like the
  change

22
Saving and Compressing Figures

• Check the file size, if gt150Kb then you may need
  to compress it down and/or reduce the size of the
  image
• Try JPEG at high compression - small file size.
  It should work, if not, scratch head
• For PowerPoint and Word presentations, 72 dots
  per inch (dpi) detail is ample
• c.f. special photoprinters which work at up to
  5760 dpi.
• ratio is 80x, so file size is 6400x bigger!
• normally anything at gt300 dpi cannot be seen

23
Inserted Picture

• Text box associated with figure
• different levels
• helps accentuate priorities
• and to show minor points
• This is a JPEG photo image
• can also label the figure itself

24
Todays Task

• Download a few images from the web (discipline
  related!)
• e.g. a cell, a protein structure, an electron or
  optical micrograph of a section of a diseased (or
  healthy) organ
• to find images use Googles image search option
• For each image
• copy into PsE and
• save as different file types and examine the
  different file sizes

25
Todays Task

• try
• using the Quick Fix commands to improve the look
  of the picture
• resizing the image
• converting to black and white
• selecting and cutting parts of the image
• cropping the overall size of the image
• labelling using different text fonts

26
Todays Task (continued)

• If you have never used PsE or any other image
  processing software the steps can be complicated
• make sure you make good use of the help and hints
  within PsE
• Then import the images into Word
• Caption them
• adjust the sizes and positions
• try also to label an existing Excel graph using
  PsE