Transcript DIGITAL IMAGE PROCESING

DIGITAL IMAGE
PROCESING
1960
NASA LUNAR AND
PLANETARY EXPLORATION
ANALOG
DIGITAL
ADC
APPLICATION OF DIGITAL
IMAGING
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ULTRASOUND
DIGITAL RADIOGRAPHY
NUCLEAR MEDICINE
CT
MRI
RADIOGRAPHY - PAST
TODAY
FLUOROSCOPY IN THE
PAST
CONVENTIONAL
DIGITAL FLUOROSCOPY
CASTELMAN (1996)
CLASSIFICATION OF THE
IMAGES BASED ON THEIR
FORM OR METHOD OF
FORMATION
IMAGES
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VISIBLE
OPTICAL
NONVISIBLE IMAGES
MATHEMATICAL
ANALOG IMAGE
CONTINUOUS IMAGES.
ANALOG IMAGE
RADIOGRAPH- CONTINUOUS DISTRIBUTION OF LIGHT
INTENSITY AS A FUNCTION OF POSITION ON THE
RADIOGRAPH
DIGITAL IMAGE
NUMERIC REPRESENTATION OR
IMAGES OF OBJECTS
ANALOG TO DIGITAL
ADC
PROCESSING
ANALOG vs DIGITAL
DIGITAL TO ANALOG
DAC
ANALOG PROCESSING
INPUT AND OUTPUT IMAGES
ARE BOTH ANALOG
DIGITAL PROCESSING
INPUT AND OUTPUT IMAGES
ARE BOTH DISCRETE
IMAGE DIGITIZATION - ADC
• SCANNING
• SAMPLING
• QUANTIZATION
SAMPLING FREQUENCY
LOW SAMPLING
ALIASING ARTIFACT
CT- SIGNAL FROM
DETECTORS: ANALOG
ANALOG
MRI- SIGNAL FROM
DETECTORS: ANALOG
ANALOG
PET- SIGNAL FROM
DETECTORS: ANALOG
ANALOG
BASIC DATA AQUSITION SCHEME IN
CT
ADC
DETECTORS
P.M. TUBE
SOLID STATE
DETECTORS
MATRIX - EYE OF THE
BEE?!
DIGITAL
RADIOGRAPH
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MATRIX
IMAGE RECEPTOR
MATRIX
PIXEL RESOLUTION IN
MATRIX
4 x 4---16 PIXELS
4 x 4 MATRIX
MATRIX
PIXEL
WHAT MATRIX?
5X4
20 PIXELS
HIGH vs LOW RESOLUTION
SPATIAL RESOLUTION
SPATIAL RESOLUTION
SPATIAL RESOLUTION= FOV/ MATRIX
IMAGE MATRIX SIZES FOR
DIFFERENT MODALITIES
• NUCLEAR MEDICINE
• 64 X 64
• CT
• 256 X 256
• MRI
• 512 X 512
• DR
• 1024 X 1024
• CR
• 2048 X 2048
DYNAMIC RANGE:
• THE RANGE OF VALUES OVER
WHICH THE SYSTEM CAN RESPOND
HOW MANY DIFFERENT SHADES CAN BE
DISPLAYED IN THE PIXEL?
DYNAMIC RANGE
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1 BIT
2 BIT
3 BIT
4 BIT
5 BIT
2 X BIT
2 COLORS
4 COLORS
8 COLORS
16 COLORS
32 COLORS
1 BIT
2 BIT
5 BIT
IMAGE MANIPULATION
• WINDOWING
• INVERSION
• IMAGE SHARPENING
WINDOW CENTER (LEVEL)
CONTROLS:
IMAGE DENSITY
WINDOW WIDTH
CONTROLS:
IMAGE CONTRAST
WINDOWING
WINDOWING
IMAGE INVERSION
IMAGE SHARPENING
RECENT ADVANCEMENTS
VIRTUAL REALITY
CINE
CT ANGIOGRAPHY