S. Mandayam/ ECE Dept./Rowan University

Freshman Clinic IIFreshman Clinic II

Spring 2005Spring 2005

Shreekanth MandayamECE Department

Rowan University

Digital ImagingDigital Imaging

April 19, 2005April 19, 2005

http://engineering.rowan.edu/~shreek/spring05/froshclinic2/

S. Mandayam/ ECE Dept./Rowan University

PlanPlan• Digital image acquisition

• Types of digital images• Monochromatic• TrueColor

• Digital Image Processing

S. Mandayam/ ECE Dept./Rowan University

Digital Image AcquisitionDigital Image Acquisition

• How do we acquire digital images?

S. Mandayam/ ECE Dept./Rowan University

S. Mandayam/ ECE Dept./Rowan University

Hurricane Fran, TIME Magazine, Sept. 16, 1996Picture Taken by: GOES-8,NASA GODDARD SPACE FLIGHT CENTER

S. Mandayam/ ECE Dept./Rowan University

S. Mandayam/ ECE Dept./Rowan University

S. Mandayam/ ECE Dept./Rowan University

S. Mandayam/ ECE Dept./Rowan University

S. Mandayam/ ECE Dept./Rowan University

ABA E-13B FontABA E-13B Font

S. Mandayam/ ECE Dept./Rowan University

S. Mandayam/ ECE Dept./Rowan University

S. Mandayam/ ECE Dept./Rowan University

S. Mandayam/ ECE Dept./Rowan University

BiometricsBiometrics

S. Mandayam/ ECE Dept./Rowan University

Types of Digital ImagesTypes of Digital Images

• Monochromatic

• TrueColor

S. Mandayam/ ECE Dept./Rowan University

Monochromatic Digital ImageMonochromatic Digital Image

.....

.....

....120

....256

..1127128 x

y

GrayLevel

f(x,y)

Pixel = Picture Element

S. Mandayam/ ECE Dept./Rowan University

Color ImagesColor Images

R B

G

W

M

CY

Mixtures of Light: Additive Primaries

S. Mandayam/ ECE Dept./Rowan University

Color PaletteColor Palette

• All shades of color that you see on a computer screen are made up by adding the 3 primary colors for each pixel

GR B

S. Mandayam/ ECE Dept./Rowan University

RGB Values for Each PixelRGB Values for Each Pixel

G= 1to 256

R= 1 to 256

B= 1to 256

“Redness” “Green-ness” “Blueness”

1 = No red256 = Bright red

1 = No green256 = Bright green

1 = No blue256 = Bright blue

S. Mandayam/ ECE Dept./Rowan University

R+G+BRG

B

R+G+BRG

B

R+G+BRG

B

R+G+BRG

B

R+G+BRG

B

R+G+BRG

B

S. Mandayam/ ECE Dept./Rowan University

DemoDemo

S. Mandayam/ ECE Dept./Rowan University

How many colors?How many colors?

• How many shades of color can you get in each pixel of a TrueColor image?

S. Mandayam/ ECE Dept./Rowan University

SummarySummary