1. A TECHNIQUE FOR
SPECTRAL PIXEL
RECONSTRUCTION
S. K. Patra, J. Saibaba, Geeta Varadan
Advanced Data Processing Research Institute
(ADRIN)
Dept. of Space, Hyderabad, India
and
S. K. Nayak
Dept. of Electronics
Berhampur University, Bhanja Vihar
Orissa, India
IGARSS 2011
Vancouver, Canada

2. OUTLINE OF THE WORK..
SPECTRAL RESPONSE (in mm)
Band IKONOS QUICKBIRD IRS-P6
Centre FWHM Centre FWHM Centre FWHM
Blu 0.485 0.07 0.485 0.07 Not Available
Grn 0.56 0.08 0.56 0.08 0.555 0.07
Red 0.66 0.06 0.66 0.06 0.650 0.06
NIR 0.83 0.14 0.825 0.14 0.815 0.09
0.4-0.5mm 0.5-0.6 mm
0.6-0.7 mm 0.7-0.9 mm
•NOT AVAILABLE IN IRS-P6!
•HANDICAP FOR TRUE COLOR?
•CREATE THE ONE..
S K Patra et.al.

3. SPECTRAL BANDS
0.40 mm - 0.7 mm 0.87 mm – 1.5 mm
~ visible ~ IR
S K Patra et.al.

4. SPECTRAL-PIXELS
FCC
TRUE Color
IKONOS RELATIVE SPECTRAL
1.20 RESPONSE
1.00
Relative Spectral Responsivity
0.80
0.60
0.40
0.20
0.00
400.00 500.00 600.00 700.00 800.00 900.00 1000.00
(0.20)
Wavelength (nm)
S K Patra et.al.

5. RADIOMETRIC
REGISTRATION
TRUE COLOR FALSE COLOR
Bt Gf
Gt = T Rf
Rt IRf
Where ,
t = True Color
f = False Color
B3  RED B4  RED
B2  GRN B3  GRN
B1  BLU B2  BLU
Bt = aB + bB Gf + cB Rf + dB IRf
Gt = aG+ bG Gf + cG Rf + dG IRf
Rt = aR+ bR Gf + cR Rf + dR IRf
where a, b, c and d are the elements of
matrix T
S K Patra et.al.

6. SPECTRAL BAND
RECONSTRUCTION
FCC TRUE
B4  red B3  red
B3  grn B2  grn
B2  blu B1  blu
NATURAL
B3  red
NEWgrn
B2  blu
Where
NEW =
¾ b2 + ¼ b4 ERDAS OUR
METHOD
IKONOS (b1:blue, b2:green,b3:red, b4:IR)
S K Patra et.al.

7. OTHER SENSORS..
QUICKBIRD
FCC TRUE OUR
METHOD
IRS-P6
LISS-3
LISS-4
AWiFS
FCC NATURAL
COLOR
S K Patra et.al.

8. DECONVOLUTION and
NOISE REDUCTION
WIENER FILTERING:
[G (u, v)  H  (u, v)]
F (u, v) 
[ H (u, v)  H  (u, v)  Nu (u, v)]
ITERATIVE EQUATION:
qk 1 ( x, y )  qk ( x, y )  [ f ( x, y )  qk ( x, y )  h( x, y )]
NOISE REDUCTION (BAYESIAN APPROACH):
p( g | f ) p( f )
p( f | g ) 
 p( g | f ) p( f )
S K Patra et.al.

9. DECONVOLUTION and
NOISE REDUCTION
WIENER
PSF
NIR •RESTORED
•DENOISED
FCC NATURAL
•RECONSTRUCTED
•RESTORED
•DENOISED
LISS-4, IRS-P6
S K Patra et.al.

10. IMAGE QUALITY MEASURE
NIR •DECONVOLVED •DECONVOLVED
•DENOISED
60
80
Contrast Contrast
55
70 Deconvolv
50 ed and
60
Gray count
denoised
50 45 origin
Gray count
al
40 40
deconvolv
30 35
ed
20 30
1050 1100 1150 1200 1140 1145 1150 1155 1160
Pixel No. Pixel No.
LISS-4, IRS-P6 S K Patra et.al.

11. SPECTRAL PIXEL
RECONSTRUCTION
LISS-4, IRS-P6
IKONOS
COMPARABLE RESOLUTION OF 5.8M
S K Patra et.al.

12. CONCLUSIONS
• DEVELOPED A FRAMEWORK
• TECHNIQUE CAN BE USED IN
GENERATING ADDITIONAL
INFORMATION
• PROVIDES HIGH-QUALITY
NATURAL COLOR IMAGES
FOR A SENSOR NOT HAVING
BLUE BAND
S K Patra et.al.