Digital Imaging

Introduction Digital Imaging is used every day in life. Has become less expensive and easier to use

than film.

Charged Couple Device (CCD)

Filtering Accomplished with a beam splitter

One pixel assigned for each color

Bayer Filter Pattern Alternates rows of green and blue, and green

and red pixels Twice as many green as red and blue

Color Space Defines how colors are mixed together to form a

specific color Two types: RGB and CYMK

Dynamic Range

Good Dynamic Range Poor Dynamic range

Interpolation

Nearest Neighbor interpolation Bilinear interpolation

Bicubic interpolation Fractal interpolation

Resolution The level of detail captured by a digital

camera

Measured in Pixels

Limited in display to the level of the monitor.

Higher the resolution, the larger the image size that can be reproduced.

Noise Interference caused by electronics

Usually the quality of the sensors and camera determines noise level

Compression of files increases noise

White Balance Used to compensate for different lighting

conditions

Fluorescent will normally cause a greenish hue

Halogen and mercury vapor will cause an orange-yellow hue

Normally automatically adjusted in the camera

File Formats Tagged Image File Format (TIFF)

Better compression format Doesn’t lose data in compression Requires adequate processor and memory

Joint Photographic Experts Group (JPEG) Most commonly used format Used mainly for natural photos As compression increases, quality declines

Storage Variety of Types

Files Normally stored in JPEG format Compact Flash, Smart Media, Memory Stick Images are transferred to the computer for

storage

Digital Imaging Uses Home Uses

Photography Email Photo editing

Business Uses Publishing

Hubble Space Telescope

Medical Uses Changing from analogue to

digital Allows Doctors to communicate

information and get opinions of specialists thousands of miles away

Government and Law Enforcement Security Screenings

Biometrics

Prevent Fraud

Other Uses Archaeology

Cosmetic Surgeons

Beauticians

Conclusion How Digital Imaging Works

Terminology

File Formats and Storage

Uses of Digital Imaging