Figures from Gonzalez and Woods, Digital Image Processing, Second Edition, 2002.

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Lecture 18

• Figures from Gonzalez and Woods, Digital Image
  Processing, Second Edition, 2002.

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Image Compression

• Images contain lots of redundancy, so compression
  is important in
• Teleconferencing
• Remote sensing
• Document and medical imaging
• FAX transmissions
• Anything that requires the transmission of an
  image requires a compression scheme

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Image Compression (2)

• Two types
• Information preservingused in medical
  applications
• Lossyused in TV, FAX transmission,etc.
• Types of redundancy
• Coding redundancy
• Interpixel redundancy
• Psychovisual redundancy

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Image Compression (3)
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Coding Redundancy
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Chapter 8 Image Compression
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Chapter 8 Image Compression
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Interpixel Redundancy
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Chapter 8 Image Compression
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Interpixel Redundancy
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Chapter 8 Image Compression
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Psychovisual Redundancy

• The eye does not respond equally to all visual
  information. Information of less relative
  importance is psychovisually redundant.

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Chapter 8 Image Compression
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Chapter 8 Image Compression
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Fidelity Measures

• RMS error and signal to noise ratio quantifiable
• Eyeball normsTelevision rating scale

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Chapter 8 Image Compression
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Chapter 8 Image Compression
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Chapter 8 Image Compression
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Coding and Decoding

• Hamming distance
• Hamming code
• Parity corrections