ISSN 19308337(print)
ISSN 19308345(online) 
Current volume

Journal archive


IPI is covered in Science Citation Index, Current Contents/Physical, Chemical & Earth Sciences (CC/PC&ES) ISI Alerting Services, Journal Citation Reports/Science Edition, Math Reviews, MathSciNet, Zentralblatt.
Inverse Problems and Imaging includes research articles of the highest quality that employ innovative mathematical and modeling techniques to study inverse and imaging problems arising in engineering and other sciences. Every published paper has a strong mathematical orientation employing methods from such areas as control theory, discrete mathematics, differential geometry, harmonic analysis, functional analysis, integral geometry, mathematical physics, numerical analysis, optimization, partial differential equations, stochastic and statistical methods. The field of applications include medical and other imaging, nondestructive testing, geophysical prospection and remote sensing as well as image analysis and image processing.
This journal is committed to recording important new results in its field and will maintain the highest standards of innovation and quality. To be published in this journal, a paper must be correct, novel, nontrivial and of interest to a substantial number of researchers and readers.
IPI will have four issues published in 2015 in February, May, August and November.
Archived in Portico 
TOP 10 Most Read Articles in IPI, July 2015
1 
Coordinate descent optimization for l^{1} minimization with application to compressed sensing; a greedy algorithm
Volume 3, Number 3, Pages: 487  503, 2009
Yingying Li
and Stanley Osher
Abstract
Full Text
Related Articles
We propose a fast algorithm for solving the Basis Pursuit problem, min_{u}
$\{u_1\: \Au=f\}$, which has application to compressed sensing.
We design an efficient method for solving the related unconstrained problem min_{u} $E(u) = u_1 + \lambda \Auf\^2_2$ based on a greedy coordinate descent
method. We claim that in combination with a Bregman iterative method, our
algorithm will achieve a solution with speed and accuracy competitive with some
of the leading methods for the basis pursuit problem.

2 
Template matching via $l_1$ minimization and its application to hyperspectral data
Volume 5, Number 1, Pages: 19  35, 2011
Zhaohui Guo
and Stanley Osher
Abstract
References
Full Text
Related Articles
Detecting and identifying targets or objects that are present in
hyperspectral ground images are of great interest. Applications
include land and environmental monitoring, mining, military, civil
searchandrescue operations, and so on. We propose and analyze an
extremely simple and efficient idea for template matching based on
$l_1$ minimization. The designed algorithm can be applied in
hyperspectral classification and target detection. Synthetic image
data and real hyperspectral image (HSI) data are used to assess the
performance, with comparisons to other approaches, e.g. spectral
angle map (SAM), adaptive coherence estimator (ACE),
generalizedlikelihood ratio test (GLRT) and matched filter. We
demonstrate that this algorithm achieves excellent results with both
high speed and accuracy by using Bregman iteration.

3 
Video stabilization of atmospheric turbulence distortion
Volume 7, Number 3, Pages: 839  861, 2013
Yifei Lou,
Sung Ha Kang,
Stefano Soatto
and Andrea L. Bertozzi
Abstract
References
Full Text
Related Articles
We present a method to enhance the quality of a video sequence
captured through a turbulent atmospheric medium, and give an
estimate of the radiance of the distant scene, represented as a
``latent image,'' which is assumed to be static throughout the
video. Due to atmospheric turbulence, temporal averaging produces
a blurred version of the scene's radiance. We propose a method
combining Sobolev gradient and Laplacian to stabilize the video
sequence, and a latent image is further found utilizing the ``lucky
region" method. The video sequence is stabilized while keeping
sharp details, and the latent image shows more consistent straight
edges. We analyze the wellposedness for the stabilizing PDE and the
linear stability of the numerical scheme.

4 
Adaptive meshing approach to identification of cracks with
electrical impedance tomography
Volume 8, Number 1, Pages: 127  148, 2014
Kimmo Karhunen,
Aku Seppänen
and Jari P. Kaipio
Abstract
References
Full Text
Related Articles
Electrical impedance tomography (EIT) is a noninvasive imaging
modality in which the internal conductivity distribution
is reconstructed
based on boundary voltage measurements.
In this work, we consider the
application of EIT to nondestructive testing (NDT) of materials and,
especially, crack detection.
The main goal is to estimate the location, depth
and orientation of a crack in three dimensions.
We formulate the crack detection task as a shape estimation problem for
boundaries imposed with Neumann zero boundary conditions.
We propose an adaptive meshing algorithm that iteratively
seeks the maximum a posteriori estimate for the shape of the crack.
The approach is tested both numerically and experimentally.
In all test cases, the EIT measurements
are collected using a set of electrodes attached on only
a single planar surface of the target 
this is often the only realizable configuration in NDT of
large building structures,
such as concrete walls.
The results show that with the proposed computational method,
it is possible to recover the position and size of the crack,
even in cases where the background conductivity is inhomogeneous.

5 
Detecting small low emission radiating sources
Volume 7, Number 1, Pages: 47  79, 2013
Moritz Allmaras,
David Darrow,
Yulia Hristova,
Guido Kanschat
and Peter Kuchment
Abstract
References
Full Text
Related Articles
In order to prevent influx of highly enriched nuclear material
through border checkpoints, new advanced detection schemes need to be
developed. Typical issues faced in this context are sources with very
low emission against a dominating natural background radiation. Sources
are expected to be small and shielded and hence cannot be detected from
measurements of radiation levels alone.
We consider collimated and Comptontype measurements and propose a detection
method that relies on the geometric singularity of small sources to
distinguish them from the more uniform background.
The method is characterized by high sensitivity and specificity and
allows for assigning confidence probabilities of detection.
The validity of our approach can be justified using properties of
related techniques from medical imaging. Results of numerical
simulations are presented for collimated and Comptontype measurements.
The 2D case is considered in detail.

6 
A MumfordShah levelset approach for the inversion and
segmentation of SPECT/CT data
Volume 5, Number 1, Pages: 137  166, 2011
Esther Klann,
Ronny Ramlau
and Wolfgang Ring
Abstract
References
Full Text
Related Articles
This paper presents a levelset based approach for the simultaneous reconstruction and segmentation of the activity as well as the density distribution from tomography data gathered by an integrated SPECT/CT scanner.
Activity and density distributions are modeled as piecewise constant functions. The segmenting contours and the corresponding function values of both the activity and the density distribution are found as minimizers of a MumfordShah like functional over the set of admissible contours and  for fixed contours  over the spaces of piecewise constant density and activity distributions which may be discontinuous across their corresponding contours. For the latter step a Newton method is used to solve the nonlinear optimality system. Shape sensitivity calculus is used to find a descent direction for the cost functional with respect to the geometrical variables which leads to an update formula for the contours in the levelset framework. A heuristic approach for the insertion of new components for the activity as well as the density function is used. The method is tested for synthetic data with different noise levels.

7 
The "exterior approach" to solve the inverse obstacle problem for the Stokes system
Volume 8, Number 1, Pages: 23  51, 2014
Laurent Bourgeois
and Jérémi Dardé
Abstract
References
Full Text
Related Articles
We apply an ``exterior approach" based on the coupling of a method of quasireversibility and of a level set method in order to recover a fixed obstacle immersed in a Stokes flow from boundary measurements.
Concerning the method of quasireversibility, two new mixed formulations are introduced in order to solve the illposed Cauchy problems for the Stokes system by using some classical conforming finite elements. We provide some proofs for the convergence of the quasireversibility methods on the one hand and of the level set method on the other hand.
Some numerical experiments in $2D$ show the efficiency of the two mixed formulations and of the exterior approach based on one of them.

8 
Towards deconvolution to enhance
the grid method for inplane strain measurement
Volume 8, Number 1, Pages: 259  291, 2014
Frédéric Sur
and Michel Grédiac
Abstract
References
Full Text
Related Articles
The grid method is one of the techniques available to measure inplane displacement and strain components on a deformed material.
A periodic grid is first
transferred on the specimen surface, and images of the grid are
compared before and after deformation. Windowed Fourier analysisbased
techniques permit to
estimate the inplane displacement and strain
maps. The aim of this article is to give a
precise analysis of this estimation process.
It is shown that the retrieved
displacement and strain maps are actually a tight
approximation of the convolution of the actual displacements and
strains with the
analysis window.
The effect of
digital image noise on the retrieved quantities is also characterized
and it is proved that the
resulting noise can
be approximated by a stationary spatially correlated noise.
These results are of utmost importance to enhance the metrological
performance of the grid method, as shown in a separate
article.

9 
A local information based variational model for selective image segmentation
Volume 8, Number 1, Pages: 293  320, 2014
Jianping Zhang,
Ke Chen,
Bo Yu
and Derek A. Gould
Abstract
References
Full Text
Related Articles
Many effective models are available for
segmentation of an image to extract all
homogenous objects within it.
For applications where segmentation of a single object identifiable by
geometric constraints within an image is desired, much less work has been done for this purpose.
This paper presents an improved selective segmentation model, without
`balloon' force, combining geometrical constraints and local image intensity
information around zero level set, aiming to overcome
the weakness of getting spurious solutions by Badshah and Chen's model [8].
A key step in our new strategy is an adaptive local band selection algorithm.
Numerical experiments show that the new model appears to be able to detect an object
possessing highly complex and nonconvex features, and to
produce desirable results in terms of segmentation quality and robustness.

10 
Solving inverse source problems by the Orthogonal Solution and Kernel Correction Algorithm (OSKCA) with applications in fluorescence tomography
Volume 8, Number 1, Pages: 79  102, 2014
ShuiNee Chow,
Ke Yin,
HaoMin Zhou
and Ali Behrooz
Abstract
References
Full Text
Related Articles
We present a new approach to solve the inverse source problem arising in Fluorescence Tomography (FT). In general, the solution is nonunique and the problem is severely illposed.
It poses tremendous challenges in image reconstructions. In practice, the most widely used
methods are based on Tikhonovtype regularizations, which minimize
a cost function consisting of a regularization term and a data fitting term.
We propose an alternative method which overcomes the major difficulties,
namely the nonuniqueness
of the solution and noisy data fitting, in two separate steps. First we find a particular solution called the orthogonal solution that satisfies the data fitting term. Then we add to it a correction function
in the kernel space so that the final solution fulfills other regularity and physical requirements. The key ideas are that the correction function in the kernel has no impact on
the data fitting, so that there
is no parameter needed to balance the data fitting and additional constraints on the solution. Moreover, we use an efficient basis to represent the source function, and introduce
a hybrid strategy combining spectral methods and finite element methods in the proposed algorithm.
The resulting algorithm can dramatically increase the computation speed over the
existing methods. Also the numerical evidence shows that it significantly improves the image resolution and robustness against noise.

Go to top

