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Showing papers in "Journal of The Optical Society of America A-optics Image Science and Vision in 2014"


Journal ArticleDOI
TL;DR: It is shown that spatial information does not provide any additional information that cannot be obtained directly from the color distribution and that the indirect aim of spatial-domain methods is to obtain large color differences for estimating the illumination direction.
Abstract: Color constancy is a well-studied topic in color vision. Methods are generally categorized as (1) low-level statistical methods, (2) gamut-based methods, and (3) learning-based methods. In this work, we distinguish methods depending on whether they work directly from color values (i.e., color domain) or from values obtained from the image's spatial information (e.g., image gradients/frequencies). We show that spatial information does not provide any additional information that cannot be obtained directly from the color distribution and that the indirect aim of spatial-domain methods is to obtain large color differences for estimating the illumination direction. This finding allows us to develop a simple and efficient illumination estimation method that chooses bright and dark pixels using a projection distance in the color distribution and then applies principal component analysis to estimate the illumination direction. Our method gives state-of-the-art results on existing public color constancy datasets as well as on our newly collected dataset (NUS dataset) containing 1736 images from eight different high-end consumer cameras.

284 citations


Journal ArticleDOI
TL;DR: A review of recent developments on generation and propagation of partially coherent beams with nonconventional correlation functions is presented.
Abstract: Partially coherent beams with nonconventional correlation functions have displayed many extraordinary properties, such as self-focusing and self-splitting, which are totally different from those of partially coherent beams with conventional Gaussian correlated Schell-model functions and are useful in many applications, such as optical trapping, free-space optical communications, and material thermal processing. In this paper, we present a review of recent developments on generation and propagation of partially coherent beams with nonconventional correlation functions.

182 citations


Journal ArticleDOI
TL;DR: The basic theoretical and computational tools used to investigate partially coherent beams' resistance to the deleterious effects of atmospheric turbulence are described and reviewed.
Abstract: Partially coherent beams hold much promise in free-space optical communications for their resistance to the deleterious effects of atmospheric turbulence. We describe the basic theoretical and computational tools used to investigate these effects, and review the research to date.

177 citations


Journal ArticleDOI
TL;DR: A microwave imaging system that combines advances in metamaterial aperture design with emerging computational imaging techniques is demonstrated and the potential of multisensor fusion is illustrated by integrating an infrared structured-light and optical image sensor to accelerate the microwave scene reconstruction and to provide a simultaneous visualization of the scene.
Abstract: We demonstrate a microwave imaging system that combines advances in metamaterial aperture design with emerging computational imaging techniques. The flexibility inherent to guided-wave, complementary metamaterials enables the design of a planar antenna that illuminates a scene with dramatically varying radiation patterns as a function of frequency. As frequency is swept over the K-band (17.5–26.5 GHz), a sequence of pseudorandom radiation patterns interrogates a scene. Measurements of the return signal versus frequency are then acquired and the scene is reconstructed using computational imaging methods. The low-cost, frequency-diverse static aperture allows three-dimensional images to be formed without mechanical scanning or dynamic beam-forming elements. The metamaterial aperture is complementary to a variety of computational imaging schemes, and can be used in conjunction with other sensors to form a multifunctional imaging platform. We illustrate the potential of multisensor fusion by integrating an infrared structured-light and optical image sensor to accelerate the microwave scene reconstruction and to provide a simultaneous visualization of the scene.

154 citations


Journal ArticleDOI
TL;DR: Results show that as in the atmosphere, also in underwater media the plane wave is more affected by turbulence as compared to the spherical wave, and Salinity-induced turbulence strongly dominates the scintillations compared to temperature- induced turbulence.
Abstract: The scintillation indices of optical plane and spherical waves propagating in underwater turbulent media are evaluated by using the Rytov method, and the variations in the scintillation indices are investigated when the rate of dissipation of mean squared temperature, the temperature and salinity fluctuations, the propagation distance, the wavelength, the Kolmogorov microscale length, and the rate of dissipation of the turbulent kinetic energy are varied. Results show that as in the atmosphere, also in underwater media the plane wave is more affected by turbulence as compared to the spherical wave. The underwater turbulence effect becomes significant at 5-10 m for a plane wave and at 20-25 m for a spherical wave. The turbulence effect is relatively small in deep water and is large at the surface of the water. Salinity-induced turbulence strongly dominates the scintillations compared to temperature-induced turbulence.

122 citations


Journal ArticleDOI
TL;DR: It is shown that reverse-mode algorithmic differentiation provides a framework for straightforward calculation of gradients of complicated error metrics without resorting to finite differences or laborious symbolic differentiation.
Abstract: In this paper, we generalize the techniques of reverse-mode algorithmic differentiation to include elementary operations on multidimensional arrays of complex numbers. We explore the application of the algorithmic differentiation to phase retrieval error metrics and show that reverse-mode algorithmic differentiation provides a framework for straightforward calculation of gradients of complicated error metrics without resorting to finite differences or laborious symbolic differentiation.

100 citations


Journal ArticleDOI
TL;DR: The scintillation index and BER versus the average signal-to-noise ratio is found by using the log-normal distributed intensity for the collimated and focused Gaussian beams, which are exhibited for various source sizes α, focal lengths F, and rates of dissipation of the turbulent kinetic energy per unit mass of fluid ε.
Abstract: Formulation of the on-axis scintillation index of a focused Gaussian beam in weak oceanic turbulence is derived by using the Rytov method, and using this formulation, the average bit error rate (BER) is evaluated. The scintillation indices of collimated, focused Gaussian, plane, and spherical beams are compared. The scintillation index and BER versus the average signal-to-noise ratio is found by using the log-normal distributed intensity for the collimated and focused Gaussian beams, which are exhibited for various source sizes α(s), focal lengths F(s), rates of dissipation of the mean squared temperature χ(T), and rates of dissipation of the turbulent kinetic energy per unit mass of fluid e. Focused beams are found to have important advantages over collimated beams. For the focused beam, as the source size increases, the scintillation index and BER decrease. When the focal length is equal to the propagation length, the BER is found to possess the smallest value. The BER is proportional to χ(T), but inversely proportional to e.

99 citations


Journal ArticleDOI
TL;DR: A Monte Carlo numerical simulation for computing the received power for an underwater optical communication system is discussed and validated and power loss between receiver and transmitter is simulated.
Abstract: A Monte Carlo numerical simulation for computing the received power for an underwater optical communication system is discussed and validated. Power loss between receiver and transmitter is simulated for a variety of receiver aperture sizes and fields of view. Additionally, pointing-and-tracking losses are simulated.

97 citations


Journal ArticleDOI
TL;DR: The image-processing steps required for consistent data acquisition with color cameras are described and a method for scene-specific color calibration that increases the accuracy of color capture when a scene contains colors that are not well represented in the gamut of a standard color-calibration target is presented.
Abstract: Commercial off-the-shelf digital cameras are inexpensive and easy-to-use instruments that can be used for quantitative scientific data acquisition if images are captured in raw format and processed so that they maintain a linear relationship with scene radiance. Here we describe the image-processing steps required for consistent data acquisition with color cameras. In addition, we present a method for scene-specific color calibration that increases the accuracy of color capture when a scene contains colors that are not well represented in the gamut of a standard color-calibration target. We demonstrate applications of the proposed methodology in the fields of biomedical engineering, artwork photography, perception science, marine biology, and underwater imaging.

87 citations


Journal ArticleDOI
Italo Toselli1
TL;DR: The power spectrum includes an effective anisotropic parameter ζ(eff) to describe anisotropy, which is useful for modeling optical turbulence when a non-Kolmogorov power law and an isotropy along the direction of propagation are present.
Abstract: In this paper, the concept of anisotropy at different atmospheric turbulence scales is introduced. A power spectrum and its associated structure function with inner and outer scale effects and anisotropy are also shown. The power spectrum includes an effective anisotropic parameter ζeff to describe anisotropy, which is useful for modeling optical turbulence when a non-Kolmogorov power law and anisotropy along the direction of propagation are present.

85 citations


Journal ArticleDOI
TL;DR: This work presents a novel computed tomography reconstruction method for the few-view problem based on fractional calculus that achieves better performance than existing reconstruction methods, including filtered back projection (FBP), the total variation-based projections onto convex sets method (TV-POCS), and soft-threshold filtering (STH).
Abstract: This work presents a novel computed tomography (CT) reconstruction method for the few-view problem based on fractional calculus. To overcome the disadvantages of the total variation minimization method, we propose a fractional-order total variation-based image reconstruction method in this paper. The presented model adopts fractional-order total variation instead of traditional total variation. Different from traditional total variation, fractional-order total variation is derived by considering more neighboring image voxels such that the corresponding weights can be adaptively determined by the model, thus suppressing the over-smoothing effect. The discretization scheme of the fractional-order model is also given. Numerical and clinical experiments demonstrate that our method achieves better performance than existing reconstruction methods, including filtered back projection (FBP), the total variation-based projections onto convex sets method (TV-POCS), and soft-threshold filtering (STH).

Journal ArticleDOI
TL;DR: The turbulence-induced transverse phase distortion limits the effectiveness of Bessel and Airy beams for applications requiring propagation over long distances in the turbulent atmosphere.
Abstract: We investigate, through simulation, the modifications to Bessel and Airy beams during propagation through atmospheric turbulence. We find that atmospheric turbulence disrupts the quasi-non-diffracting nature of Bessel and Airy beams when the transverse coherence length (Fried parameter) nears the initial aperture diameter or diagonal, respectively. The turbulence-induced transverse phase distortion limits the effectiveness of Bessel and Airy beams for applications requiring propagation over long distances in the turbulent atmosphere.

Journal ArticleDOI
TL;DR: The noninvasive visualization of capillary flow and structure provided by AOSLO split-detection shows great promise for studying ocular and systemic conditions that affect the retinal vasculature.
Abstract: Imaging of the retinal vascular structure and perfusion was explored by confocal illumination and nonconfocal detection in an adaptive optics scanning light ophthalmoscope (AOSLO), as an extension of the work by Chui et al. [Biomed. Opt. Express 3, 2537 (2012)]. Five different detection schemes were evaluated at multiple retinal locations: circular mask, annular mask, circular mask with filament, knife-edge, and split-detector. Given the superior image contrast in the reflectance and perfusion maps, the split-detection method was further tested using pupil apodization, polarized detection, and four different wavelengths. None of these variations provided noticeable contrast improvement. The noninvasive visualization of capillary flow and structure provided by AOSLO split-detection shows great promise for studying ocular and systemic conditions that affect the retinal vasculature.

Journal ArticleDOI
TL;DR: This work proposes a three-parameter family of asymmetric Bessel-Gauss (aBG) beams with integer and fractional orbital angular momentum (OAM).
Abstract: We propose a three-parameter family of asymmetric Bessel–Gauss (aBG) beams with integer and fractional orbital angular momentum (OAM). The aBG beams are described by the product of a Gaussian function by the nth-order Bessel function of the first kind of complex argument, having finite energy. The aBG beam’s asymmetry degree depends on a real parameter c≥0: at c=0, the aBG beam is coincident with a conventional radially symmetric Bessel–Gauss (BG) beam; with increasing c, the aBG beam acquires a semicrescent shape, then becoming elongated along the y axis and shifting along the x axis for c≫1. In the initial plane, the intensity distribution of the aBG beams has a countable number of isolated optical nulls on the x axis, which result in optical vortices with unit topological charge and opposite signs on the different sides of the origin. As the aBG beam propagates, the vortex centers undergo a nonuniform rotation with the entire beam about the optical axis (c≫1), making a π/4 turn at the Rayleigh range and another π/4 turn after traveling the remaining distance. At different values of the c parameter, the optical nulls of the transverse intensity distribution change their position, thus changing the OAM that the beam carries. An isolated optical null on the optical axis generates an optical vortex with topological charge n. A vortex laser beam shaped as a rotating semicrescent has been generated using a spatial light modulator.

Journal ArticleDOI
TL;DR: A modified delay-and-sum reconstruction method is implemented, which takes into account the large aperture of the detector, leading to more than fivefold improvement in the tangential resolution in photoacoustic (and thermoacoustic) tomography.
Abstract: Spatial resolution in photoacoustic and thermoacoustic tomography is ultrasound transducer (detector) bandwidth limited. For a circular scanning geometry the axial (radial) resolution is not affected by the detector aperture, but the tangential (lateral) resolution is highly dependent on the aperture size, and it is also spatially varying (depending on the location relative to the scanning center). Several approaches have been reported to counter this problem by physically attaching a negative acoustic lens in front of the nonfocused transducer or by using virtual point detectors. Here, we have implemented a modified delay-and-sum reconstruction method, which takes into account the large aperture of the detector, leading to more than fivefold improvement in the tangential resolution in photoacoustic (and thermoacoustic) tomography. Three different types of numerical phantoms were used to validate our reconstruction method. It is also shown that we were able to preserve the shape of the reconstructed objects with the modified algorithm.

Journal ArticleDOI
TL;DR: For advancing age, sensitivity decline in all chromatic systems was confirmed, though with a marked acceleration after 60 years (reflected by the power function exponent >1) and more pronounced for the tritan system.
Abstract: The present study, an extension of Paramei [J. Opt. Soc. Am. A, 29, A290, 2012], provides normative data on chromatic discrimination, using the Cambridge Colour Test, for normal trichromats aged 10–88 years. Findings are in accord with a two-phase variation across the life span: chromatic sensitivity improves in adolescence, reaches a maximum around 30 years, and then undergoes a gradual decrease. Indicative parameters are Protan (P), Deutan (D), and Tritan (T) vector lengths and major axes and axis ratios of Ellipses. Trivector data are modeled as non-monotonic combinations of power functions, with goodness-of-fits RP2=0.23, RD2=0.23, and RT2=0.45. For advancing age, sensitivity decline in all chromatic systems was confirmed, though with a marked acceleration after 60 years (reflected by the power function exponent >1) and more pronounced for the tritan system.

Journal ArticleDOI
TL;DR: Methods that enable handling of multi-domain modulations and reconstruction of polarization information using linear algebra are described and practical choices regarding use of either Fourier or direct channels are made to make these methods more immediately useful.
Abstract: Channeled polarimeters measure polarization by modulating the measured intensity in order to create polarization-dependent channels that can be demodulated to reveal the desired polarization information. A number of channeled systems have been described in the past, but their proposed designs often unintentionally sacrifice optimality for ease of algebraic reconstruction. To obtain more optimal systems, a generalized treatment of channeled polarimeters is required. This paper describes methods that enable handling of multi-domain modulations and reconstruction of polarization information using linear algebra. We make practical choices regarding use of either Fourier or direct channels to make these methods more immediately useful. Employing the introduced concepts to optimize existing systems often results in superficial system changes, like changing the order, orientation, thickness, or spacing of polarization elements. For the two examples we consider, we were able to reduce noise in the reconstruction to 34.1% and 57.9% of the original design values.

Journal ArticleDOI
TL;DR: General and simple sampling rules of thumb are derived that allow the user to calculate the distribution for any propagation distance and it is shown how these rules can be extended to fast-Fourier-transform-based algorithms to increase calculation efficiency.
Abstract: In this paper, we address the problem of calculating Fresnel diffraction integrals using a finite number of uniformly spaced samples. General and simple sampling rules of thumb are derived that allow the user to calculate the distribution for any propagation distance. It is shown how these rules can be extended to fast-Fourier-transform-based algorithms to increase calculation efficiency. A comparison with other theoretical approaches is made.

Journal ArticleDOI
TL;DR: A new approach based on quasi-random detector subsampling is proposed, enabling one to employ fewer measurements than expected from classical sampling theory without significant loss of information in projection tomography.
Abstract: We investigate new sampling strategies for projection tomography, enabling one to employ fewer measurements than expected from classical sampling theory without significant loss of information. Inspired by compressed sensing, our approach is based on the understanding that many real objects are compressible in some known representation, implying that the number of degrees of freedom defining an object is often much smaller than the number of pixels/voxels. We propose a new approach based on quasi-random detector subsampling, whereas previous approaches only addressed subsampling with respect to source location (view angle). The performance of different sampling strategies is considered using object-independent figures of merit, and also based on reconstructions for specific objects, with synthetic and real data. The proposed approach can be implemented using a structured illumination of the interrogated object or the detector array by placing a coded aperture/mask at the source or detector side, respectively. Advantages of the proposed approach include (i) for structured illumination of the detector array, it leads to fewer detector pixels and allows one to integrate detectors for scattered radiation in the unused space; (ii) for structured illumination of the object, it leads to a reduced radiation dose for patients in medical scans; (iii) in the latter case, the blocking of rays reduces scattered radiation while keeping the same energy in the transmitted rays, resulting in a higher signal-to-noise ratio than that achieved by lowering exposure times or the energy of the source; (iv) compared to view-angle subsampling, it allows one to use fewer measurements for the same image quality, or leads to better image quality for the same number of measurements. The proposed approach can also be combined with view-angle subsampling.

Journal ArticleDOI
TL;DR: The Stokes matrix formalism is used and symmetries of Müller matrix scattering are used to establish links among the mathematical symmetry of each geometric configuration to find wide application in models of the LIDAR scattering process.
Abstract: Symmetry relationships for optical observations of matter generally fall into several common scattering geometries. The “planetary” configuration is preferred by observers of extraterrestrial planets, “laboratory” observations are performed in the biomedical research field, and the LIDAR configuration is preferred by those using lasers to probe optical properties of horizontal surfaces with mirror or axial symmetry. This paper begins with the Stokes matrix formalism and uses symmetries of Muller matrix scattering to establish links among the mathematical symmetries of each geometric configuration. We finish the paper by identifying and correcting an influential misapplication of rotational scattering matrices in the literature. The corrected equation should find wide application in models of the LIDAR scattering process.

Journal ArticleDOI
TL;DR: This paper proposes a novel generating method that fits both the coordinates and the normals of discrete data points on a freeform surface based on the mathematical multiobjective optimization theory and is suited for generating some freeform polynomial surfaces.
Abstract: Through direct design methods, both coordinates and normals of discrete data points on a freeform surface are usually obtained, but traditionally the freeform surface is generated by only fitting the coordinates. In this paper, a novel generating method that fits both the coordinates and the normals is proposed based on the mathematical multiobjective optimization theory. This new method is suited for generating some freeform polynomial surfaces. Two design examples are introduced, and their optical performance is significantly improved when applying the new method compared with the traditional method. This new method is validated to be effective, and it is widely useful as long as the coordinates and the normals are provided in advance.

Journal ArticleDOI
TL;DR: Results confirm that CCT for best appreciation of paintings is higher than normally used in museums, and the viewing conditions, real or simulated, have only a minor effect.
Abstract: In a previous study based on monitor simulations of artistic paintings, it was found that the average correlated color temperature (CCT) of daylight preferred by a large set of observers to illuminate paintings was around 5100 K. The goal of the present study was to test if this result holds in real viewing conditions, i.e., with real paintings and real light sources. The same 11 paintings were tested in real conditions illuminated by a spectrally tunable light source and with accurate monitor simulations. To ensure uniform illumination across the paintings, only a central part of the paintings was visible to the observers. It was found that the average CCT preferred for real and monitor viewing conditions were very similar, 5500 and 5700 K, respectively. The somewhat larger CCT obtained with monitor viewing in relation to the former study was only observed in some paintings and was attributed to the smaller viewing area. These results confirm that CCT for best appreciation of paintings is higher than normally used in museums, and the viewing conditions, real or simulated, have only a minor effect.

Journal ArticleDOI
TL;DR: The generalized Kubelka-Munk (gKM) equations are much more accurate at approximating the solution of the RTE and are able to generalize KM theory to take into account general boundary sources and nonhomogeneous terms, for example.
Abstract: We derive Kubelka–Munk (KM) theory systematically from the radiative transport equation (RTE) by analyzing the system of equations resulting from applying the double spherical harmonics method of order one and transforming that system into one governing the positive- and negative-going fluxes. Through this derivation, we establish the theoretical basis of KM theory, identify all parameters, and determine its range of validity. Moreover, we are able to generalize KM theory to take into account general boundary sources and nonhomogeneous terms, for example. The generalized Kubelka–Munk (gKM) equations are also much more accurate at approximating the solution of the RTE. We validate this theory through comparison with numerical solutions of the RTE.

Journal ArticleDOI
TL;DR: This work shows that color appearance, including individual differences never explained before, are predicted by a model in which S-cone signals are combined with L versus M signals in the outer retina.
Abstract: De Valois and De Valois [Vis. Res.33, 1053 (1993)] showed that to explain hue appearance, S-cone signals have to be combined with M versus L opponent signals in two different ways to produce red-green and yellow-blue axes, respectively. Recently, it has been shown that color appearance is normal for individuals with genetic mutations that block S-cone input to blue-ON ganglion cells. This is inconsistent with the De Valois hypothesis in which S-opponent konio-geniculate signals are combined with L-M signals at a third processing stage in cortex. Instead, here we show that color appearance, including individual differences never explained before, are predicted by a model in which S-cone signals are combined with L versus M signals in the outer retina.

Journal ArticleDOI
TL;DR: A novel optical information encryption and authentication scheme that uses asymmetric keys generated by thephase-truncation approach and the phase-retrieval algorithm that proves the effectiveness of the proposed scheme.
Abstract: We propose a novel optical information encryption and authentication scheme that uses asymmetric keys generated by the phase-truncation approach and the phase-retrieval algorithm. Multiple images bonded with random phase masks are Fourier transformed, and obtained spectra are amplitude- and phase-truncated. The phase-truncated spectra are encoded into a single random intensity image using the phase-retrieval algorithm. Unlike most of the authentication schemes, in this study, only one encrypted reference image is required for verification of multiple secured images. The conventional double random phase encoding and correlation techniques are employed for authentication verification. Computer simulation results and theoretical explanation prove the effectiveness of the proposed scheme.

Journal ArticleDOI
TL;DR: There is an ensemble perception of hue, but this is affected by the categorical and metric relationships of the elements in the ensemble, and increasing the perceptual difference of ensemble hues inhibited this mean bias.
Abstract: This study investigated the perception of colorful ensembles and the effect of categories and perceptual similarity on their representation. We briefly presented ensembles of two hues and tested hue recognition with a range of seen and unseen hues. The average hue was familiar, even though it never appeared in the ensembles. Increasing the perceptual difference of ensemble hues inhibited this mean bias, and the categorical relationship of hues also affected the distribution of familiarity. The findings suggest there is an ensemble perception of hue, but this is affected by the categorical and metric relationships of the elements in the ensemble.

Journal ArticleDOI
TL;DR: Initial computational simulations show that the full-phase PC-DRPE has the potential to require fewer photons for authentication than the amplitude-based PC-RAE, and their statistical parameters are used for authentication.
Abstract: We investigate a full-phase-based photon-counting double-random-phase encryption (PC-DRPE) method. A PC technique is applied during the encryption process, creating sparse images. The statistical distribution of the PC decrypted data for full-phase encoding and amplitude-phase encoding are derived, and their statistical parameters are used for authentication. The performance of the full-phase PC-DRPE is compared with the amplitude-based PC-DRPE method. The PC decrypted images make it difficult to visually authenticate the input image; however, advanced correlation filters can be used to authenticate the decrypted images given the correct keys. Initial computational simulations show that the full-phase PC-DRPE has the potential to require fewer photons for authentication than the amplitude-based PC-DRPE.

Journal ArticleDOI
TL;DR: A relationship for the complex amplitude of generalized paraxial Hermite-Gaussian (HG) beams is deduced and it is shown that under certain parameters, these beams transform into the familiar HG modes and elegant HG beams.
Abstract: A relationship for the complex amplitude of generalized paraxial Hermite–Gaussian (HG) beams is deduced. We show that under certain parameters, these beams transform into the familiar HG modes and elegant HG beams. The orbital angular momentum (OAM) of a linear combination of two generalized HG beams with a phase shift of π/2, with their double indices composed of adjacent integer numbers taken in direct and inverse order, is calculated. The modulus of the OAM is shown to be an integer number for the combination of two HG modes, always equal to unity for the superposition of two elegant HG beams, and a fractional number for two hybrid HG beams. Interestingly, a linear combination of two such HG modes also presents a mode that is characterized by a nonzero OAM and the lack of radial symmetry but does not rotate during propagation.

Journal ArticleDOI
TL;DR: A texture descriptor for color texture classification specially designed to be robust against changes in the illumination conditions, which outperforms the original LBP approach and its color variants, even when these are computed after color normalization.
Abstract: This paper presents a texture descriptor for color texture classification specially designed to be robust against changes in the illumination conditions. The descriptor combines a histogram of local binary patterns (LBPs) with a novel feature measuring the distribution of local color contrast. The proposed descriptor is invariant with respect to rotations and translations of the image plane and with respect to several transformations in the color space. We evaluated the proposed descriptor on the Outex test suite, by measuring the classification accuracy in the case in which training and test images have been acquired under different illuminants. The results obtained show that our descriptor outperforms the original LBP approach and its color variants, even when these are computed after color normalization. Moreover, it also outperforms several other color texture descriptors in the state of the art.

Journal ArticleDOI
TL;DR: A fast recursive method is developed for the radial polynomials that occur in the kernel function of the Jacobi-Fourier moments, which is suitable for computation of the JFMs of the highest orders.
Abstract: A high-precision and fast algorithm for computation of Jacobi-Fourier moments (JFMs) is presented. A fast recursive method is developed for the radial polynomials that occur in the kernel function of the JFMs. The proposed method is numerically stable and very fast in comparison with the conventional direct method. Moreover, the algorithm is suitable for computation of the JFMs of the highest orders. The JFMs are generic expressions to generate orthogonal moments changing the parameters α and β of Jacobi polynomials. The quality of the description of the proposed method with α and β parameters known is studied. Also, a search is performed of the best parameters, α and β, which significantly improves the quality of the reconstructed image and recognition. Experiments are performed on standard test images with various sets of JFMs to prove the superiority of the proposed method in comparison with the direct method. Furthermore, the proposed method is compared with other existing methods in terms of speed and accuracy.