CSCE763 Digital Image Processing

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CSCE-763 Digital Image Processing Lecture 1
Introduction to Digital Image
Instructor Tiecheng Liu
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One picture is worth more than a thousand words.
---- Anonymous
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We have gone a long way
The oldest existing photograph in history, 1839
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The first camera (not film camera!), 1646
Lewis Daguerreotype Camera, 1852
Today
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Applications of digital imaging technology
Satellite imaging and remote sensing
And more
Medical science, industry inspection
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The process of Image Acquisition
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In order to better understand digital image, we
need to understand light. But, what on earth is
light?
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But, some scientists have different opinion.
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(EM wave)
(Particle)
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Electromagnetic Wave
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And then whats color?
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Newtons Prism (1666)
And so the true Cause of the Length of that
Image was detected to be no other, than that
Light is not similar or Homogenial, but consists
of Difform Rays, some of which are more
Refrangible than others."
Newton here ?
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• Color is a subjective human perception of light
  of different frequency.
• No absolute color in nature, only EM wave of
  different wavelengths.
• Different people may perceive color differently.
• Some animals may perceive a color spectrum less
  or more than we human can see.

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How can we see color and image?
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Anatomy of Human Eye
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Density distribution of human visual receptors
Cone 6-7 million total, near fovea, sensitive to
color (bright-light vision) Rod75-150 million,
widely distributed, sensitive to low level of
illumination. (dim-light vision)
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We humans have visual illusions (of course)
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Contrast Illusion
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Optical Illusion
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DIGITAL IMAGE ACQUISITION DEVICE Image Sensors
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Image Acquisition Using Single Sensor
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Image Acquisition Using Sensor Strips
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CCD Image Sensor
Inventors George Smith and Willard Boyle Bell
Lab. 1969
First CCD sensor
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CCD Image Sensor (cont.)
How a CCD image sensor works.
CCD
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Layout of CCD sensor photosites
Standard CCD
Fuji Super CCD
For details of Fuji super CCD image sensor, check
http//photos8.msn.com/resources/targeted/en-us/ed
itorial/FujiFourthGen.html
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CMOS Image Sensor
1. CMOS image sensor with peripheral circuits.
2. Color filters for CMOS image sensor.
3. PCB of a digital camera.
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Foveon X3
A Dramatically Different DesignThe revolutionary
design of Foveon X3 direct image sensors features
three layers of pixel sensors. The layers are
embedded in silicon to take advantage of the fact
that red, green, and blue light penetrate silicon
to different depthsforming the world's first
direct image sensor.
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New Foveon X3 Image Sensor
For details, check http//www.foveon.com
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Optics of Lenses a real zoom lens
Lens groups
Aperture of lens
Optical path a zoom lens
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Aberration of lenses

• Geometric Aberration
• Barrel distortion
• Pin-cushion distortion
• Chromatic Aberration