30 August 2006

Sensing

Refresher on Complex Numbers

• http://www.clarku.edu/~djoyce/complex/

• http://www.dspguide.com/ch30.htm

World is practically continuous intimespacecolorbrightness

1011 dynamic range brightness

Digital World

• Quantized in:– time– space– color– brightness

how many frames/second?

how many pixels?

how many primaries?

how many bits/pixel?

Outline

• Image formation– Pinhole camera– Point source (x-ray)– Lens

• Sensors– Film– Image orthicon– CCD

Pinhole Camera

Features?

Tradeoffs?

Lens

Features?

Tradeoffs?

How TV Worked(in the old days)

• What is a cathode? What is a cathode ray? What is a cathode ray tube?

• What is a phosphor? What are "phosphorescence" and "fluorescence"?

• How does a "cathode ray tube" CRT work? • How was the TV image acquired? • What is a "raster" scan?• What are horizontal and vertical "sync"? • What is "interlace"? Why do that? • What determines the "resolution"? • What is "gamma" and why should it be corrected? • How did they get color? • How do decisions made in the 40's affect CG, CV, and IP today?

Cathode Ray Tube

Vidicon (tv camera)

X-Ray

X-Ray

Charge Coupled Device

From: http://www.science.ca/scientists/scientistprofile.php?pID=129