image noise iii - university of arizonadial/ece533/notes14.pdfece/opti533 digital image processing...
TRANSCRIPT
ECE/OPTI533 Digital Image Processing class notes 278 Dr. Robert A. Schowengerdt 2003
IMAGE NOISE IIIPeriodic, Nonstationary Noise
• Example: Mariner 9 (Chavez, 1975)
Generated by Ultraviolet Spectrometer (UVS) motor during image readout
• Model:
, fs m n,( ) f m n,( ) fη m n,( )– f m n,( ) f m n,( )η m n,( )–= = 1– η m n,( ) 1≤ ≤
published original and processed images
ECE/OPTI533 Digital Image Processing class notes 279 Dr. Robert A. Schowengerdt 2003
IMAGE NOISE IIIProcedure (modifed from Chavez, 1975)
Periodic, nonstationary noise removal
• Estimate noise period
• Create noise “template”
• Correlate template with noisy image
• Multiply correlation map and noisy image Ñ> estimated noise map
• Subtract weighted, estimated noise map from noisy image
ECE/OPTI533 Digital Image Processing class notes 280 Dr. Robert A. Schowengerdt 2003
IMAGE NOISE III noise template (16x zoom) - 3 periods of sinewave with period = 27 pixels
normalized correlation between noisy image and noise template
normalized correlation times noisy image - estimated noise map
border effectfrom correlation
ECE/OPTI533 Digital Image Processing class notes 281 Dr. Robert A. Schowengerdt 2003
IMAGE NOISE III
noisy image processed image
ECE/OPTI533 Digital Image Processing class notes 282 Dr. Robert A. Schowengerdt 2003
IMAGE NOISE IIIDetector Striping• Model: “global” DN statistics from each detector should be the
same
• Adjust gain and offset for each detector to equalize global statistics
Choose one detector’s statistics, or the average statistics over all detectors, as “reference”
ECE/OPTI533 Digital Image Processing class notes 283 Dr. Robert A. Schowengerdt 2003
IMAGE NOISE III
line-by-line average DN
detector mean DN std dev DN1 69.96 44.632 62.67 35.653 73.19 48.884 87.59 53.00
ECE/OPTI533 Digital Image Processing class notes 284 Dr. Robert A. Schowengerdt 2003
IMAGE NOISE III
• If detectors have nonlinear gain or offset, use CDF-based reference contrast stretch (see Notes page 6-12)
destriped to equal mean DN and standard deviation DN
global mean DN = 69.59global std dev DN = 44.63
(detector 1 is reference)
ECE/OPTI533 Digital Image Processing class notes 285 Dr. Robert A. Schowengerdt 2003
IMAGE NOISE IIIDetector Banding
• Use combination of LPFs and HPFs (Crippen, 1989)
Heuristic algorithm for Landsat TM (16 detectors/scan)
1 row x 101 column LPF
33 row x 1 column HPF
1 row x 31 column LPF
***
noisyimage
cleanedimage
isolates low-frequency noise
isolates high-frequency banding
reduces diagonal artifacts from HPF
ECE/OPTI533 Digital Image Processing class notes 286 Dr. Robert A. Schowengerdt 2003
IMAGE NOISE IIIexample
• “Cosmetic”-type algorithm, not based on calibration data
• Filter sizes must be adapted to particular sensor detector configuration
original
water-masked
101 column LP 33 row HP
31 column LP water-masked
filtered
water-masked
ECE/OPTI533 Digital Image Processing class notes 287 Dr. Robert A. Schowengerdt 2003
IMAGE NOISE IIIReferences
• Chavez, P. S., Jr. (1975). “Simple high-speed digital image processing to remove quasi-coherent noise patterns.” in: , Washington, D.C., American Society of Photogrammetry: 595-600.
• Crippen, R. E. (1989). “A simple spatial filtering routine for the cosmetic removal of scan-line noise from Landsat TM P-tape imagery.” 55(3): 327-331.
• Eliason, E. and A. S. McEwen (1990). “Adaptive box filter for removal of random noise from digital images.” 56(4): 453-458.
• Lee, J. (1983). “Digital image smoothing and the sigma filter.” 24: 255-269.
• Lee, J.-S. (1980). “Digital image enhancement and noise filtering by use of local statistics.” PAMI-2(2): 165-168.
• Lee, J.-S. (1981). “Speckle analysis and smoothing of synthetic aperture radar images.” 17: 24-32.
• Nagao, M. and T. Matsuyama (1979). “Edge preserving smoothing.” 9: 394-407.
• O’Handley, D. A. and W. B. Green, “Recent Developments in Digital Image Processing at the Image Processing Laboratory at the Jet Propulsion Laboratory,” Proc. IEEE, Vol. 60, No. 7, July 1972, pp. 821-828.
• Rindlfeish, T. C., J. A. Dunne, H. J. Frieden, W. D. Stromberg, and R. M. Ruiz, “Digital Processing of the Mariner 6 and 7 Pictures,” , Vol. 76, No. 2, January 10, 1971, pp. 394-417.
• Schowengerdt, R. A., , Second Edition, Academic Press, 1997.