DESTRIPING AND INPAINTING OF REMOTE SENSING IMAGES
USING MAXIMUM A-POSTERIORI METHOD
Huanfeng Shen 3, *, Tinghua Ai a , Pingxiang Li b
3 School of Resource and Environmental Science, Wuhan University, Wuhan 430079, China - shenhf@whu.edu.cn
b The State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing
Commission I, WG 1/1
KEY WORDS: Correction, Retrieval, Algorithms, Image, Radiometric
ABSTRACT:
In a large number of spacebome and airborne multi-detector spectrometer imagery, there commonly exist image stripes and random
dead pixels. The techniques to recover the image from the contaminated one are called image destriping (for stripes) and image
inpainting (for dead pixels). In order to constrain the solution space according to a priori knowledge, this paper presents a maximum
a posteriori (MAP) based algorithm for both destriping and inpainting problems. In the MAP framework, the likelihood probability
density function (PDF) is constructed based on a linear image observation model, and a robust Huber-Markov model is used as the
prior PDF. A gradient descent optimization method is employed to produce the desired image. The proposed algorithm has been
tested on images of different sensors. Experimental results show that it performs quite well in terms of both quantitative
measurements and visual evaluation.
1. INTRODUCTION
Remote sensing images often suffer from the common problems
of stripe noises and linear or random dead pixels. These
severely degrade the quality of the measured imagery, and will
introduce a considerable level of noise when processing data
without correction of them. The correction of image stripes is
commonly called as image destriping. The recovery of the dead
pixels sometimes goes by the name of dead pixel replacement.
In this paper, however, we use another more attractive name,
i.e., image inpainting, which has been widely used in the field
of digital image processing(Bertalmio et al., 2000).
At the highest level, destriping techniques can be divided into
frequency domain or spatial domain algorithms. The simplest
frequency domain algorithm is to process the image data with a
low-pass filter using discrete Fourier transform (DFT). This
method has the advantage of being usable on geo-rectified
images, but it often does not remove all stripes and leads to
significant blurring within the image. Chen et al. (Chen et al.,
2003) proposed a method to distinguish the striping-induced
frequency components using the power spectrum, and then
remove the stripes using a power finite-impulse response filter.
Some researchers remove the stripes using wavelet analysis
which takes advantage of the scaling and directional properties
to detect and eliminate striping patterns (Chen et al., 2006;
Torres and Infante, 2001).
In the spatial domain, most destriping algorithms examine the
distribution of digital numbers for each sensor, and adjusts this
distribution to some reference distribution (Gadallah et al.,
2000). These methods are equalization(Algazi and G. E. Ford,
1981), histogram matching (Horn and Woodham, 1979;
Wegener, 1990), moment matching (Gadallah et al., 2000), and
others. More recently, Rakwatin et al. (Rakwatin et al., 2007)
combined histogram matching with facet filter for stripe noise
reduction in MODIS data. These methods have a similarity
assumption for the image data.
For the inpainting problem, the nearest-neighbor, average or
median value replacement methods are commonly employed
(Ratliff et al., 2007). The main disadvantage of these methods is
that they are employable only when the dead area is small (for
example, the width of the dead line is only one or two pixels).
Even for dead areas just a little larger, these methods will
produce obvious artifacts.
In this paper, we formulate the destriping and inpainting
problems using Maximum A Posteriori (MAP) estimation. Our
motivation is to constrain the solution space of the ill-posed
problems according to a priori knowledge on the form of the
solution using the MAP framework. To our best knowledge,
this is the first time that remote sensing destriping or inpainting
problem is formulated using probabilistic approach.
2. THE PROPOSED ALGORITHM
2.1 Image Observation Model
Letting z xy and g x v , respectively denote the input radiance to
be measured and the senor output of location (x,y) , the
relationship between z xy and g^, can be related by a linear or
nonlinear function. In this paper, we assume the degradation
process can be linearly described as in (Gadallah et al., 2000;
* Corresponding author.
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