In this presentation, we deal with the design of a filter based on the geodesic distance affinity which can able to suppress the low frequency artifacts as a post-processing step after the main Winner filter restoration. We consider the multispectral signal model in the case of the Winner filter restoration independently in each image channel. The impulse response of the obtained filter is a linear combination of generalized filters optimized with respect to different criteria. The main idea of the proposed algorithm is based on assumption that low frequency outliers and the additional noise in the different image channels are not correlate to each other, thus the affinity space formed by of the opposite channels can effectively suppress the main restoration artifacts. The performance of the proposed filter analyzed and compared in terms of the PSNR accuracy. The proposed method demonstrates the ability to suppress distortion due to the low frequency artifacts.
Two consecutive frames of a lateral navigation camera video sequence can be considered as an appropriate approximation to epipolar stereo. To overcome edge-aware inaccuracy caused by occlusion, we propose a model that matches the current frame to the next and to the previous ones. The positive disparity of matching to the previous frame has its symmetric negative disparity to the next frame. The proposed algorithm performs probabilistic choice for each matched pixel between the positive disparity and its symmetric disparity cost. A disparity map obtained by optimization over the cost volume composed of the proposed probabilistic choice is more accurate than the traditional left-to-right and right-to-left disparity maps cross-check. Also, our algorithm needs two times less computational operations per pixel than the cross-check technique. The effectiveness of our approach is demonstrated on synthetic data and real video sequences, with ground-truth value.
A robust and efficient method for overcoming the negative effects of long-time occlusion in the tracking process is presented. The proposed approach is based on the matching of multiple trajectories in time. Trajectories are sets of 2-D points in time and in a joint ground plane of the world coordinate system. In order to avoid mismatches due to possible measurement outliers, we introduce an integral distance between compared trajectories. The proposed method can also be considered as an interpolation algorithm for a disconnected trajectory during the blackout. Thus this technique solves one of the most difficult problems of occlusion handling: the matching of two unconnected parts of the same trajectory.
A new effective algorithm of impulse noise suppression is proposed. Conventional filtering schemes usually utilize a fixed shape for the moving window, such as a rectangle or circle. In contrast, the proposed algorithm exploits a signal-dependent shape for the moving window. We suggest a simple adaptive algorithm of impulse noise detection in monochrome images that takes into account the size of signal gradient neighborhoods and image statistics. Experimental results show superior performance of the proposed algorithm compared to that of conventional algorithms in terms of both subjective and objective criteria.
KEYWORDS: Image filtering, Digital filtering, Gallium nitride, Detection and tracking algorithms, Interference (communication), Sensors, Signal detection, Nonlinear filtering, Signal attenuation, Algorithm development
A new effective algorithm of impulse noise suppression is proposed. First an iterative procedure composes a helper function associated with the filtered image, then this helper function allows realizing efficient impulse detection for the conventional two steps filtering scheme. In our previous papers we suggested a simple adaptive algorithm of impulse noise detection in monochrome images that takes into account the size of signal gradient neighborhoods and image statistics. In this work the detection scheme is noticeably ameliorated. Further investigations shown that the proposed modification of the gradient based impulse detector highly improves the results of the filtering in terms of both subjective and objective criteria.
The goal of many image processing tasks is to recover an ideal high-quality signal from data that are degraded by impulsive noise, because the human visual system is very sensitive to the high amplitude of noise signals, thus noise in an image can result in a subjective loss of information. This work presents an elegant solution to the impulsive noise removal problem. The proposed technique takes into account three important factors for image filtering, i.e. noise attenuation, edge preservation, as well as detail retention. The conventional filtering schemes utilize a fixed shape of the moving window such as rectangle and circle. In contrast, the proposed spatially connected filter works with the moving window of signal-dependent shape. Experimental results show the superior performance of the proposed filtering algorithm compared to the conventional schemes in terms of both subjective and objective evaluations.
Adaptive nonlinear filters based on nonparametric Spearman’s correlation between ranks of an input scene computed in a moving window and ranks of a target for illumination-invariant pattern recognition are proposed. Several properties of the correlations are investigated. Their performance for detection of noisy objects is compared to the conventional linear correlation in terms of noise robustness and discrimination capability. Computer simulation results for a test image corrupted by mixed additive and impulsive noise are provided and discussed.
KEYWORDS: Image filtering, Optical filters, Nonlinear filtering, Digital filtering, Sensors, RGB color model, Detection and tracking algorithms, Linear filtering, Interference (communication), Color image processing
Nonlinear vector median filters (VMF) and their variants represents one of the most popular approaches for color image processing. In this paper a novel effective method for detection and removal impulse noise in highly corrupted color images has been proposed. First, window operator based on an explicit use of spatial relations between color image elements to detect impulse noise is used. Then the spatially connected modification of VMF for removal of previously detected impulsive noise has been employed. The performance of the proposed detector and filter for detecting and suppressing of impulsive noise in test images is compared to conventional vector medium algorithms.
A new technique for local contrast enhancement using rank-order filters with spatially adaptive neighborhoods is proposed. The technique is based on the unsharp masking operation. However, instead a linear lowpass filtering we use various rank-order smoothing operations. The smoothing is performed over the pixels of spatially adaptive neighborhoods of details to be enhanced and their surrounding backgrounds. Various rank-order filters for local enhancement of small and middle-size details are implemented. Computer simulation results using a real aerial image are provided and discussed.
A new approach to design rank-order filters based on an explicit use of spatial relations between image elements is proposed. Many rank-order processing techniques may be implemented by applying the approach, such as noise suppression, local contrast enhancement, and local detail extraction. The performance of the proposed rank-order filters for suppression a strong impulsive noise in a test interferogram-like image is compared to conventional rank- order algorithms. The comparisons are made using a mean square error, a mean absolute error, and a subjective human visual error criteria.
A new algorithm to compute a precise 3-D shape of a moving object for color motion stereo is described. Input data is obtained from a single color CCD camera and a moving belt. Three-dimensional shape recovery in motion stereo is formulated as a matching optimization problem of multiple color stereo images. It is shown that the problem of matching among multiple color motion stereo images can be carried out with use circular decorrelation of a color signal. Three- dimensional shape recovery using real color motion stereo images demonstrates a good performance of the algorithm in terms of reconstruction accuracy.
A new algorithm to compute precise depth estimates for motion stereo is described. Input data is obtained from a single CCD camera and a moving belt. It is shown that the problem of matching among multiple motion stereo images can be effectively carried out by use of adaptive correlation matching. Experimental results with real stereo images are presented to demonstrate the performance of the algorithm.
CD-ROM, CD-I, VCD, CD-DA, Photo-CD, DVD is a partial list of storage devices widely used in multimedia application. Unlimited possibilities available for multimedia developers requires the adequate understanding of possibilities, advantages and disadvantages of each of them. This report gives the analysis of available hardware and software for developing and authoring multimedia projects. Digital image processing methods are considered. The described methods were realized in some multimedia projects.
New methods of calculating computer-generated true-color rainbow holograms (CGTCRH) are proposed. The main idea of the proposed work is based on the additive properties of holographic wave front reconstruction such that the result hologram is a superposition of three (or more) holograms, each of them produces different color reconstruction of the same object. These techniques allows obtaining the true- color object reconstruction. White light reconstruction results are discussed. A new method of calculating CGTCRH which are reconstructed by a white light point source is proposed. The presented CGTCRH are the analog of the well- known rainbow holograms, but proposed technique allows to obtain the true-color object reconstruction. White light and monochromatic light reconstruction results are discussed. New method of calculating computer-generated true-color rainbow holograms are proposed. These techniques allows obtaining the true-color object reconstruction. The main idea of the proposed work is based on the additive properties of holographic wave front reconstruction such that the result hologram is a superposition of three (or more) holograms, each of them produces different color reconstruction of the same object.
A new method of calculating computer-generated true-color rainbow holograms (CGTRRH) which are reconstructed by a white light point source is proposed. The presented CGTRGH are the analog of the well-known rainbow holograms, but the proposed technique allows us to obtain the true-color object reconstruction. White light and monochromatic light reconstruction results are discussed.
KEYWORDS: Holograms, Computer generated holography, 3D image reconstruction, 3D displays, Holography, 3D modeling, Mathematical modeling, Solids, Digital holography, Photography
Two computer-generated display macro holograms (CGDMH) have been synthesized to demonstrate the possibility of holographic display of 3D objects given by their mathematical descriptions only. Three dimensional models of the objects and shaded 2D projections in varying viewing directions were generated using the methods of computer graphics. For each projection, a Fourier hologram was synthesized and encoded by the kinoform method. The recording of the obtained digital kinoforms on a commercially available photographic film was done by a computer controlled laser device. This process produces, after film development and bleaching, a facet CGDMH. The complete CGDMHs have a size of 672 X 672 mm2 and consist of 900 elementary holograms of 256 X 256 samples each, calculated for different directions within the solid angle of +/- 90 degree(s). They allow the visual representation of 3D objects with good quality.
Two large-scale computer generated holograms (CGH) were synthesized using methods of computer graphics for calculating 3D object models and 2D projections from them. 900 elementary projections (views) of the objects were calculated and subsequently encoded as CGHs using the kinoform method. The recording of the holograms was done on customary photographic material with succeeding bleaching. The whole multiplex large-scale CGH has a size of 600 * 600 mm2 and requires 3.6 Mbytes of storage. All software was written in C under the UNIX operating system. The CGHs are appropriate for representation of 3D objects with high quality.
We used isolated radioulnar bones (fused radial and ulnar bones) of subadult European moose collected in various environmentally polluted areas of Finland. The bones were radiographed and holographic interference pictures, for holographic nondestructive testing (HNDT), were produced by using small caudocranial bending forces. The cortical index values were measured in the diaphyses and samples were taken for mineral studies from the mandibles of the same animals. Results indicated that the bones obtained from the heavily polluted area showed biomechanical response comparable to the bones developed partially without mothers milk. Differences were also seen in morphometrical and radiological studies. The mineral contents studied did not differ significantly from randomly collected samples of the same age category. We therefore conclude that environmental factors may influence the bone matrix development.
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