מערכות ראיה ושמיעה
Visual and Auditory Systems
Spectrum
Photometry
• Measuring light …
Colorimetry
• Modeling of color sensation
• Color addition
• Color subtraction
• Image processing
(noise removal, edge detection,
compression, inpainintg etc.)
Bayer filter
Colorimetry
CIE gamut
• CIE
standard observer
• RGB
color addition
• HSV
• CMYK
color subtraction
• YIQ, YUV
television broadcasting
• YCbCr
digital television transmission, JPEG
HSV gamut
Colorimetry
• Dichromatism:
The Human Visual System (HVS)
The Human Visual System (HVS)
Vision Research
• Physiology
• Psychophysics
Automatic Gain
Control
Vision Research
Hermann’s
Grid
3 3
2.5 2.5
Vision Research 2
1.5
2
1.5
• HVS is sensitive to:
1 1
0.5 0.5
• Local features.
0 0
0 0.5 1 1.5 2 2.5 3 0 0.5 1 1.5 2 2.5 3
3
2.5
• Spatial frequency (gratings). 2
1.5
1
Contrast Sensitivity Function 0.5
0
0 0.5 1 1.5 2 2.5 3
1
Signal Representation 0
-1
-3 -2 -1 0 1 2 3
1
• How does the HVS represent 0
images? -1
1
-3 -2 -1 0 1 2 3
• Fourier series. 0
-1
• Gabor functions.
-3 -2 -1 0 1 2 3
t
• Wavelets 1
0
1
-1
-3 -2 -1 0 1 2 3
0.5 1
0 0
-4 -3 -2 -1 0 1 2 3 4
1
-1
-3 -2 -1 0 1 2 3
0.5 1
0 0
-3 -2 -1 0 1 2 3
1
-1
-3 -2 -1 0 1 2 3
0.5 t
0
-3 -2 -1 0 1 2 3
t
The Ear
Subjective Hearing
• Properties of the human auditory system are utilized
in audio compression algorithms such as MP3.