Digital Imaging
Utah State University Extension
Eric Hawley
“Agenda”
• Digital Camera features, terms, and technologies
• Transferring images from camera to computer
• “Developing” digital images:
– Understanding resolution and image size (How do you get a 5x7
image?)
• Editing, transforming, and processing images
• Understanding and working with different image file
•
formats
How to adjust an image for different applications (such
as web, e-mail, archival and print)
– Editing “blemishes”
– Adjusting color balance, contrast, brightness, etc.
– Batch tools – making similar changes to a large group of photos
(Using Photoshop and Photoshop Elements)
Things that Don’t Go Away
• There are always two people in every
picture: the photographer and the viewer.
Adams
~Ansel
• No photographer is as good as the simplest
camera.
~Edward Steichen
• I hate cameras. They are so much more sure
than I am about everything.
~John Steinbeck
• Buying a Nikon doesn't make you a
photographer. It makes you a Nikon
owner. ~Author Unknown
“Post Photographic” Skills
• Getting files off of the camera or scanner
• Archiving
• Choosing and adjusting image file type
• Editing
• Scaling size/resolution for web/e-mail
• Scaling size/resolution for print
Terms and Concepts
• Pixels
• Image Resolution
• “Output” or “Physical” Image Size
• Color Depth
• File Formats
To the drawing board…
Back from the drawing board…
File Formats
“Web Friendly” File Formats
• JPEG images (*.jpg, *.jpeg, *.jpe, *.jfif)
- many compression levels (lossy)
• CompuServe images (*.gif)
- compression format: LZW (lossless)
- special: interlaced, non-interlaced
• Portable network graphic images
(*.png)
- compression format: LZ77
JPEG/JPG
“Photographical”
• JPEG is designed for compressing either
full-color or grey-scale digital images of
"natural", real-world scenes. It does not
work so well on non-realistic images, such
as cartoons or line drawings.
• Remember, the 'P' in JPEG stands for
'Photographic'. It was designed to be used
to compress photographic image data.
(Joint Photographic Experts Group)
GIF
“Solid colors and lines”
• GIF images can contain a maximum of
256 colors (8 bits) or less…
(Graphics Interchange Format)
…if you create a GIF image of a red arrow,
you can customize the file to have only
two colors, red and white.
PNG
• PNG: Essentially ‘Extended’ GIF Images.
Allows for up to 24-bit color including
control of opacity. Saving, restoring and
re-saving a PNG image will not degrade its
quality. PNG does not support animation
like GIF does. “Patent-Free”
“Edit Friendly”
• Uncompressed or lossless compression
– Saved, edited, saved, edited without penalty
– Good for archives… (Why?)
“Edit Friendly”
(web poor)
file formats
(Either uncompressed or lossless compression)
• TIFF images (*.tif, *.tiff)
•
•
•
- uncompressed (Compressed: packed bits, LZW*, CCITT T.4, Deflate, new style JPEG…)
Standard Windows bitmap images (*.bmp)
- uncompressed
Photoshop images (*.psd, *.pdd)
- uncompressed
RAW images (*.raw)
- shockingly uncompressed
Four Steps to “Preparing”
Digital Photos
Step A.
• Archive “important” photos in their
BIRTHDAY SUITS. (native, un-edited, unresaved, happy, naked state)
• (Meaning, make a copy and DON’T work on
the copy…)
Step B
• If you will be doing lots of
saving, editing, saving, editing…
FIRST, convert to a
lossless or un-compressed form.
Step C
• Edit and Adjust
– For appropriate pixel size
– Cropping, color, orientation
– Any other editing
Step D.
• Save in the desired production format…
Done!
On to software…
• Picasa2
• Windows XP
– Filing System, Picture Details, Viewing…
• Irfanview
• Photoshop Elements or CS