Search

In this paper a new method is proposed for intelligent sort of battery from waste paper based on Invariant Moments and Fractal Dimension (IMFD). In IMFD, a new distinctive feature that based on the edge contours is extracted to describe the target picture. At first invariant moments technique is used to extract Hus seven moments as the global descriptors from the target image. Then the fractal dimensions are extracted as local invariant descriptors by using Fractal Dimension. At last, a combing descriptor is built according the distinctive feature, which combines the global descriptor and the local descriptor together. The features are highly distinctive, and can be matched with high probability against a large database of features. The practical tests performed in this article show that the proposed method has a significant effect on increasing the stability, the accuracy of classification, and also can effectively against the huge-information during the image processing.

This study investigated the effects of bending curvature of simulated e-paper displays (−10 cm, plane and 10 cm) and ambient illuminance (50, 500, 6000 and 12,000 lx) on the visual performance of young and elderly users for simulated electronic-paper displays. In total, 24 people comprising 12 young and 12 elderly users participated in this study. Young users demonstrated significantly enhanced visual performance using the simulated electrophoretic ink (E ink) e-paper display with ambient illuminance set at 50 and 500 lx; however, participants did not demonstrate significantly different visual performance using the 2 simulated e-paper displays with ambient illuminance set at 6000 and 12,000 lx. The bending curvature did not exhibit significant effects on the visual performance of young participants under various ambient illuminances. The elderly participants exhibited significantly enhanced visual performance using the simulated E ink e-paper display only when ambient illuminance was set at 50 lx; however, participants did not exhibit significantly different visual performance using the two simulated e-paper displays with ambient illuminance set at other levels. Elderly users exhibited significantly enhanced visual performance when the bending curvature was set at 10 cm, with ambient illuminance set at 50 lx. Elderly users also demonstrated significantly enhanced visual performance under bending curvature settings of 10 cm and plane, with ambient illuminance set at 500 lx. However, the bending curvature of the simulated e-paper did not exhibit significant effects on the visual performance of elderly participants under ambient illuminance settings of 6000 and 12,000 lx.

Multi-sensor object detection and tracking on a highway scene with radar measurements is presented. The estimation algorithm is the random finite set based Bernoulli filter, working in the Bayesian framework. The recursion for calculating the Bayes estimation is implemented as a particle filter. A method is presented for calculating the likelihoods, suitable for particle filtering performed with moving sensors, assuming additive Gaussian measurement noise. In our approach, for calculating the posterior estimate of the object state, the measurement likelihoods are computed in the state space, instead of the measurement space, by mapping each measurement to the global coordinate system. The map consists of a nonlinear and an affine part. While the affine transformation trivially preserves the Gaussian nature, the nonlinear is well-proven to be approximated as affine too. This approach allows the particles to be drawn directly from the state space, hence the evaluation of the measurement model is not needed, which saves computational power.

Effects of character size under ambient illuminances and light sources on legibility of electronic paper displays (electrophoretic display and cholesteric liquid crystal display) were studied and compared with paper. Sixty subjects participated in a letter-search task in the experiment. The results showed that search speed depends on the illuminance but not light source. Search speed increased as the illuminance increase from 300, 700 to 1500 lx. Search speed also increased with the increase of character size, from character height of 1.4 mm (9.6 min visual angle), 2.2 mm (15.1 min visual angle) to 3.3 mm (22.7 min visual angle), and the increase leveled off at 4.3 mm (29.6 min visual angle). The effect of character size on accuracy was also significant. Accuracy increased with the increase of character size. However, the effect of illuminance and light source on accuracy was not statistically significant. Based on the results of this study, it seems that E-paper displays may need greater illumination (700 lx or higher), greater character size (3.3 mm or 22 min of visual angle).

International audience; This paper investigates the classification of photographic paper tex-tures using visual descriptors. Such classification is called fine grain due to the very low inter-class variability. We propose a novel image representation for photographic paper texture categorization, relying on the incorporation of a powerful local descriptor into an efficient higher-order model deviation where texture is represented by com-puting statistics on the occurrences of specific local visual patterns. We perform an evaluation on two different challenging datasets of photographic paper textures and show such advanced methods in-deed outperforms existing descriptors.

In this paper, we achieved the floating 3D image based on integral photography theory to display the image in an oblique viewing angle on portable device. Considering the repeated image overlapping problem in the integral image system, it can be solved by adjusting the receiving angle. In the future, the floating 3D image could integrate with the 3D interactive system to provide more realistic visual experience.

Multi-projection three-dimensional (3D) display system with dual projection using uniaxial crystal is proposed. The dual projection means that multiple images are generated by double refraction in the uniaxial crystal according to the polarization state of a single projection unit. The concept of dual projection method is equivalent to physically separated two projectors. We apply the dual projection method in the multi-projection 3D display and double the number of viewing zones while maintaining the number of projectors. Through the experiment, we implement the four-view multi-projection 3D display providing super multi-view condition with two projection units. Experimental results verify the feasibility of the proposed system.

This paper proposed an improved method based on adaptive with threshold wavelet transform denoising, according to image is often affected by noise pollution in the process of acquisition and transmission, compared with the advantages and disadvantages of traditional digital filtering method. It extracts the structure information and details of the image. It can adaptively select wavelet transform of optimal decomposition level and soft threshold to achieve the optimal noise reduction effect. The Simulation results demonstrate that this theory can effectively filter Gaussian noise and Salt and pepper noise, at the same time well protect the image details and achieve better visual effects.

In order to consummate the management of bank paper, a new algorithm which can recognize the areas of paper tape in bundle of paper money is presented. Image segmentation is used to divide the image into several sub-blocks. Specifically, image entropy is computed in each sub-block. Experimental in different algorithms, including color training algorithm and the median filter and edge detection algorithm, demonstrates its real-time, effectiveness and robustness.

There exist low recognition speed and non-ideal recognition effect in some recognition algorithms of paper currency value. One of very important reasons is that the shooting angle makes the image inclined. This paper firstly analyses the binarization processing of RMB 100-Yuan image and then the method of acquiring straight lines in image is discussed. Thus, the inclination angle of image is calculated by using the obtained straight lines. Finally, through rotation transformation, the inclination image is corrected. The experimental results show that this algorithm has a good corrected effect to the inclination image of paper currency and improves the image recognition effect.

Fiducial markers are used in image processing to determine locations of interest based on fixed points of reference. There are a number of applications for these markers across various fields ranging from advertising to radiation therapy. The four-square fiducial markers discussed in this manuscript allow for the determination of locations of interest on digital images. These new markers are easily detected, provide information about image orientation, and allow for local color sampling. The markers are intended for use in a pharmaceutical assessment process in which images of colorimetric chemical tests are taken by a smart-phone in the field, uploaded to a database, and analyzed to collect quantitative information about the colors resulting from the tests. KEYWORDS: Image Processing; Digital Imaging; Fiducial Markers; Image Thresholding; Color Calibration; MATLAB; Paper Analytical Devices

Paper properties, including the chemical or optical characteristics influence the quality and colorimetric characteristics of final printed colors. In this study, the effect of gloss, texture, and whiteness of the paper on the printed colors were investigated. The study was applied on 10 coated papers with different texture, gloss or whiteness, and the same grammage using two inkjet printers. It was found that the reproducibility of the printer can be affected with the paper brand, and this effect is statistically dependent on the brand of printer. The kind of paper significantly influences the light fastness of the final printed colors, and this effect statistically depends on the printer. Although, the paper's properties such as gloss and whiteness affect the gamut volume, it is not totally possible to model this effect. The effect of paper on the colorimetric values of the final printed colors is statistically significant. However, the influence of the brand of printer on the color changes via the paper difference is not statistically provable. Edge frequency technique was introduced as an appropriate method for computing texture properties of papers. The texture difference computed by this method shows a suitable correlation with the color differences caused by changing the paper's texture; however, it depends on the printer's brand. Furthermore, there is a good correlation between the Edge frequency difference and the gamut volume variation for papers with different texture while the other parameters such as gloss and whiteness are the same. © 2012 Wiley Periodicals, Inc. Col Res Appl, 38, 284–291, 2013

Paper, as an important substrate of printed matter, the performance will impact on the color reproduction. Brightness, as a key index of paper performance, affects the apparent color of paper directly. It was investigated that the printed samples with different brightness have been evaluated the influence of paper brightness on color reproduction by the methods of subjective and objective color difference evaluation. Three kinds of paper with different brightness have been selected as substrate of printed samples. The standard test color blocks have been printed to do corresponding objective color difference evaluation to different paper by CIEDE2000 color-difference formulae methods. Meanwhile, the standard test images with difference contents have been printed on three kinds of paper, which was subjected to subjective color difference evaluation for visual evaluation of standard test images in standard observe conditions. The results of subjective and objective color difference evaluation have been combined to analyze the effect of paper brightness to color reproduction, and different visual influence to images of difference content, and could provide certain reference for selecting the brightness performance of paper in color reproduction.

In this paper, we describe the development of a system for evaluating an specific quality characteristic of recycled paper sheets using techniques of image analysis and pattern recognition. We call Bumpiness the phenomenon of interest, which is new in the literature on paper quality. This phenomenon is characterized by the appearance of macroscopic undulations on the paper sheet surface that may emerge shortly or some time after its production. We explore the detection and measurement of this defect by means of computer vision and statistical pattern recognition techniques that may allow early detection at the production site. Our goal is to give an scalar continuous measure of Bumpiness. We propose features computed from Gabor filter banks (GFB) and discrete wavelet transforms (DWT) for the characterization of paper sheet surface Bumpiness in recycled paper images. The starting point is to state the problem as a classification of the paper sheet images into two classes: low and high Bumpiness. In this setting we obtain, with both proposed texture modelling approaches (GFB and DWT), classification accuracies comparable to the agreement between human observers. The best performance is obtained using DWT features. Finally, we propose as the scalar index of Bumpines the fisher discriminant analysis (FDA) function defined on the space of the best features for the classification task. We perform an innovative validation process of this Bumpiness index, based on the ordering of random pairs of images, obtaining a very high agreement with the human observers.

This paper presents an empirical study to investigate the use of photometric stereo (PS) for micro-scale 3D measurement of paper samples. PS estimates per-pixel surface orientation from images of a surface captured from the same viewpoint but under different illumination directions. Specifically, we investigate the surface properties of paper to test whether they are sufficiently well approximated by a Lambertian reflectance model to allow veridical surface reconstruction under PS and explore the range of conditions for which this model is valid. We present an empirical setup that is used to conduct a series of experiments in order to analyse the applicability of PS at the micro-scale. In addition, we determine the best 4, 6, and 8 light source tilt (illumination) angles with respect to multi-source micro-scale PS. Furthermore, an intensity based image registration method is used to test the accuracy of the recovery of surface normals. The results demonstrate that at the micro-scale: (a) Lambert model represents well the data sets with low root mean square (RMS) error between the original and reconstructed image, (b) increasing the light sources from 4 to 8 reduces RMS error, and (c) PS can be used to extract veridical surface normals.

Three perspectives were devised to characterize Chinese ink blurring, namely the ink absorption, the unevenness of the outlines at the blurring heads, and the difference of the tones at the blurring heads. Laboratory handsheets from softwood kraft pulp, having various basis weights, were prepared with or without wet pressing. They were soaked in Chinese ink for various times as the Klemm method. After drying, they were scanned by an image scanner set at 800 dpi to prepared bit-mapped images. These images were changed to binary images. Using the obtained images, various blurring indices based on the three perspectives were introduced. The blurring indices based on the ink absorption, the adsorbed ink amount and the capillary rise, for the handsheets without wet pressing were larger than those for the handsheets with wet pressing. Other blurring indices showed few differences between these papers with or without wet pressing. Thus, the three perspectives have different character in blots evaluation.

The study used the simulated e-paper to investigate how the bending radius of curvature (−10 cm, plane, and 10 cm) and 12 text/background color-combinations of e-paper affect subjects’ visual performance and subjective preference under various ambient illuminance conditions (200 and 500 lx). Analysis results indicated that the bending curvature and ambient illuminance did not significantly affect subjects’ visual performance. However, subjects visual performance differed significantly for different text/background color combinations of the simulated e-paper. When the background color of the simulated e-paper was set to yellow-like condition and the luminance of the text was low (2.2 and 4.6 cd/m 2 ), subjects’ visual performance was best. Regarding the subjective preferences of subjects, the results of this research also demonstrated that the bending curvature, text/background color combinations and ambient illuminance all significantly affected the subjective preferences of subjects. Subjects exhibited the best preference under the following settings: bending curvature of the simulated e-paper set to plane; background color of the simulated e-paper set to yellow-like condition and low text luminance (2.2 or 4.6 cd/m 2 ); high ambient illuminance (500 lx).

The increased use of CRT monitors for displaying and controlling stimuli in studies of surface color poses problems of comparability with data obtained with traditional paper-and-illuminant methods. A review of comparable studies using the two methodologies revealed that CRT studies tend to report larger contrast effects. To investigate factors that may be responsible for this difference, simultaneous lightness contrast was measured using both CRT and paper-and-illuminant presentations. The spatial distribution of luminance in the whole field of view and the visual angles subtended by the displays were controlled. The CRT presentation yielded contrast effects twice as big as those measured for a paper surface in a homogeneously illuminated room. However, a paper display under Gelb lighting yielded almost exactly the same effect size as that measured in the CRT presentation. These results demonstrate that contrast effects in both modes of presentation are affected by the spatial distribution of luminance beyond the basic experimental stimuli.

Stripes are important features for scrap paper images mosaics. The stripe feature extraction can directly affect the effect of mosaics. A method of stripe feature extraction from scrap paper images is proposed in this paper. In order to obtain the background binary image, the original scrap paper images are firstly carried out by close operation and binarization. Secondly, the single pixel edges are extracted by using edge detection operator. Finally, the crossing points of stripes and the boundary of the background are detected by using the Progressive Probabilistic Hough Transformation. The length, angle and direction features of stripes are also extracted during this process. The experimental results show that the method of stripe feature extraction proposed in this paper is reasonable. By using this method the stripe features can be extracted from scrap paper images quickly and correctly. It provides features for the subsequent image mosaics.

The problem of ‘structure from motion’ concerns the reconstruction of the three-dimensional structure of a scene from its projection onto a moving two-dimensional surface. Such a problem is solved effectively by the human visual system, judging from the ease with which we perform delicate control tasks involving vision as a sensor such as reaching for objects in the environment or driving a car. In this paper we study ‘structure from motion’ from the point of view of dynamical systems: we first formalize the problem of 3-D structure and motion reconstruction as the estimation of the state of certain nonlinear dynamical models. Then we study the feasibility of ‘structure from motion’ by analyzing the observability of such models. The models that define the visual motion estimation problem for feature points in the Euclidean 3-D space are not locally observable; however, the non-observable manifold can be easily isolated by imposing metric constraints on the state space. One of the peculiarities of vision as a sensor is its richness , which can be a disadvantage when we are interested only in few of the unknown parameters. For instance, if we want to control the direction of heading of our car by measuring brightness values on our retina, we have to overcome the effects that the shape of the environment, its reflectance properties, illumination and other quantities have on our measurements. Invariance to undesired parameters can be achieved by appropriate modeling or by choice of representation of the parameter space. We propose and analyze models for 3-D structure that are independent of 3-D motion and vice versa. Estimating unknown parameters from such models amounts to the identification of nonlinear and implicit systems with parameters on differentiable manifolds, such as a sphere or the so-called essential manifold . © 1997 Elsevier Science Ltd.

We deal with the 3D reconstruction of deformed paperlike surfaces given a template and a single perspective image, for which the internal camera parameters are known. The general problem is ill-posed. We show that when the surface rulings are parallel the problem is well-posed. Given a procedure to recover the rulings direction, this particular problem is equivalent to the reconstruction of a 2D curve seen from a set of ID camera pairs given a ID template. Paper can be physically modeled by exploiting local properties. This allows us to formulate the reconstruction problem by non linear variational optimization. We provide experimental results which validate our approach on simulated and real data.

The glossiness of paper and painted objects is one of the important factors in the evaluation of their manufactured quality. Although the gloss of specimens is judged visually in quality control, specular glossiness measuring instruments now offer a replacement for visual evaluation. However, in evaluation of glossiness in a group consisting of specimens of different colors, the specular glossiness measuring instrument has certain deficiencies, as a result of which the measured glossiness values are not proportional to human evaluations of glossiness (psychological glossiness); however, the instrument is suitable to a group consisting of specimens of similar color. Thus, research intended to obtain suitable measurements of physical glossiness for colored specimens was undertaken. First, an attempt was made to approximate the gloss appearance perceived by the human eye by using a model of the intensity distribution of the light reflected from a specimen surface. Utilizing the obtained gloss appearance, a new physical glossiness is defined and is provisionally named “specular diffusion ratio glossiness” (GSD): The new glossiness is shown to be nearly proportional to the psychological glossiness by the use of the glossiness measuring apparatus developed in this study. In the latter half of this paper, the application of the new glossiness index GSD to currently used specular glossiness measuring instruments is proposed, and its utility is confirmed by using various colored papers. Finally, problems for future research are identified. © 1997 Scripta Technica, Inc. Syst Comp Jpn. 28 (1): 95–112, 1997

Protecting data transmitted over the Internet has become a critical issue driven by the progress in data digitalization and communications networking over the past decade. The content being transmitted can be in the form of images, text and voice. To ensure that transmitted data are secure and cannot be tampered with or noticed by malicious attackers, several approaches have been proposed. Steganography is one general approach among them. The hiding capacity and image quality of stego-images are two major measures with which to evaluate an image hiding scheme. To enhance the hiding capacity of Fridrich et al.'s scheme, an improved image hiding scheme for grayscale images based on wet paper coding is proposed in this paper. The significant difference between Fridrich et al.'s scheme and ours is that we shuffle all the pixels in the host image by adopting toral automorphism, then segment all pixels before using our proposed wet pixel hiding strategies to hide the data. Experimental results show that our proposed scheme embeds a larger-sized secret image while maintaining acceptable image quality of the stego-image better than Fridrich et al.'s scheme does. Moreover, the computational cost of our proposed scheme is significantly less than that of Fridrich et al.'s scheme because inverse matrix and multiplication operations are not required. Therefore, our proposed scheme is suitable for real time applications.

Annotation watermarking (sometimes also called caption or illustration watermarking) denotes a specific application of watermarks, which embeds supplementary information directly in the media, so that additional information is intrinsically linked to media content and does not get separated from the media by non-malicious processing steps such as image cropping or compression. Recently, nested object annotation watermarking (NOAWM) has been introduced as a specialized annotation watermarking domain, whereby hierarchical object information is embedded in photographic images. In earlier work, the Hierarchical Graph Concept (HGC) has been suggested as a first approach to model object relations, which are defined by users during editing processes, into a hierarchical tree structure. The original HGC method uses a code-book decomposition of the annotation tree and a block-luminance algorithm for embedding. In this article, two new approaches for embedding nested object annotations are presented and experimentally compared to the original HGC approach. The first one adopts the code-book scheme of HGC using an alternative embedding based on Wet Paper Codes in blue-channel LSB domain, whereas the second suggests a new method based on the concept of intrinsic signal inheritance by sub-band energy and phase modulation of image luminance blocks. A comparative experimental evaluation based on more than 100 test images is presented in the paper, whereby aspects of transparency and robustness with respect to the most relevant image modifications to annotations, cropping and JPEG compression, are discussed comparatively for the two code-book schemes and the novel inheritance approach.

Most computer graphics researchers would agree that the pixel is the fundamental atomic element of imaging. But what is a pixel? The simple notion of a hardware displayable pixel becomes far more complex when it is examined more closely. Early 2D windowing systems considered a pixel to be a little square. A more enlightened signal processing approach thinks of a pixel as a point sample of a continuous function. Many signal processing problems occur since physical pixels can only have positive values. Hardware pixels are usually given with 8 bits of resolution. But the precise translation of these bit patterns into physical intensities is often not specified. More careful treatment of intensity encoding takes into consideration gamma correction and dithering, as well as the intensity sensitivity of the human eye. Color pixels are generally thought to have Red, Green and Blue components. A closer examination leads to the concept of a pixel as some projection of a full spectral distribution that must take into account the response of the eye and the physics of the display emitters. In addition, some modern displays, like LCD panels, have a predictable geometric offset between the color emitters. This has implications on the proper spatial filtering of an image in addition to any color matching problems. Compositing and blending images leads to the creation of a fourth channel, called alpha, to represent an amount of geometric coverage. The exact meaning of this transparency channel has also been a subject of debate. Furthermore, the traditional single alpha channel is often used to represent colored object transparency. This is another approximation to a more accurate approach that progresses through usage of three alpha channels per pixel to, ultimately, a whole spectral distribution for transmission as well as emission. Finally, there are reasons to specify still more quantities, such as depth information, on a pixel-by-pixel basis. Ultimatly, like the blind men and the elephant, a pixel means different things to different people. In fact, when we consider the proper handling of color, geometry and transparency we realize that an ordinary hardware pixel is simply a bad image compression technique.

The goal of this work is the fully-automated detection of cellulose fibre cross sections in microtomy images. A lack of significant appearance information makes edges the only reliable cue for detection. We present a novel and highly discriminative edge fragment descriptor that represents angular relations between fragment points. We train a Random Forest with a plurality of these descriptors including their respective center votes. In such a way, the Random Forest exploits the knowledge about the object centroid for detection using a generalized Hough voting scheme. In the experiments we found that our method is able to robustly detect fibre cross sections in microtomy images and can therefore serve as initialization for successive fibre segmentation or tracking algorithms.

Image retrieval is generally implemented by image matching or based-regions retrieval, but itpsilas difficult to balance retrieval performance and complexity. Query images may appear with different scales and rotations in different images, so a hierarchical image segmentation is proposed to partition the retrieved images into equal blocks with different sizes at different levels. Then, the similar metrics of these sub-blocks to query image, are evaluated to retrieve those sub-blocks with contents in query images. Meanwhile, information about scales and locations of query objects in retrieved images can also be returned. The hierarchical block image retrieval schemes with geometric invariants, normalized histograms and their combinations are tested by experiments via a database with 500 images, respectively. The retrieval accuracy with geometric invariants as invariant features can achieve 78% for the optimal similar metric threshold. Furthermore, the scheme can also work with different size images.

We correct a fundamental formula from paper ''A Robust Real-Time Ellipse Detector'' by Zhang and Liu published in journal ''Pattern Recognition'' in 2005.

In this study, the authors examine the process of authenticating paper media using the unique fibre structure of a piece of paper (the so-called ‘paper fingerprint’) In particular, the authors look at methods to authenticate a paper fingerprint when text has been printed over the authentication zone. The authors show how alpha-masked correlation can be applied to this problem and develop a modification to this technique that is more closely matched to the requirements of this problem and produces an improvement in performance. They also investigate two methods of pixel inpainting to remove printed text or marks from the authentication zone and allow ordinary correlation to be performed. The authors show that these methods can perform as well as alpha-masked correlation. They derive confidence estimates for one of the matching processes. Finally, the authors investigate some methods for improving the robustness to forgery and rotation of the matching process.

In this paper “wobulation” is presented. Wobulation is a cost-effective method of increasing the resolution of digital projection systems without changing the spatial light modulator (SLM). Multiple sub-frames of data are generated from each frame of image data. An optical image shifting mechanism displaces the projected image of each sub-frame by a fraction of a pixel. The sub-frames are projected in rapid succession, thereby appearing as if they were projected simultaneously and superimposed. The resulting image has significantly higher resolution than images produced by unwobulated systems having the same number of SLM pixels.

Focus cues specify inappropriate 3d scene parameters in conventional displays because the light comes from a single surface, independent of the depth relations in the portrayed scene. We examine the efficacy of a stereo-display prototype designed to minimize these problems by using multiple image planes to present near-correct focus cues. Each eye's view is the sum of several images presented at different focal distances. Variation in focal distance is provided by either multiple beam splitters or by use of a switchable lens. The stimulus to accommodation is more consistent with the portrayed depth than with conventional displays. Compared to a normal, fixed-distance display, observers show improved stereoscopic performance in different psychophysical tasks including speed of fusing stereoscopic images. The multiple image-planes approach provides a practical solution for some shortcomings of conventional displays.

This paper provides a methodology which bridges the gap between a simple color-difference metric and a full spatio-chromatic vision model to predict color differences. Because luminance and chromatic visual channels differ greatly in their spatial sensitivities, more than a single number is needed for specific applications—e.g., performance of softcopy displays. On the other hand, a full vision model implies dependence on the displayed images as well as on the display device, and may be impractical to implement. The compromise proposed here is to adopt in certain cases two color-difference metrics, one for luminance and the other for chrominance. Because chromatic coordinates are not luminance-independent in uniform color spaces such as CIELAB, the endpoints of the color difference are made isoluminous prior to transformation to a uniform-color space.

Mechanisms of the artifacts accompanying with image motion on Flat Panel Displays (FPDs), e.g. motion blur, jerky motion, and dynamic false contour, etc deteriorating picture quality, will be explained on the bases of image projected on the retina. The solutions for decreasing the artifacts will be reviewed and other possible artifacts will be discussed.

A reflection-type integral imaging scheme for displaying three-dimensional images and its modifications are proposed. A concave mirror array instead of a lens array is adopted for the image integration. Its feasibility is demonstrated by basic experiments.

We have developed a new scaling technique, which we call “Advanced Scaling with Preserving Extracted Contour's Transition (ASPECT)”. When an image is expanded, it generally lose uniformity and become blurred. ASPECT change the scaling ratio at the contour of an image so that it can maintain sharpness of the expanded image. Thus the technology can create a crisp expanded image without producing artifacts caused by non-uniformity or overshooting.

Map products, including charts and large-scale engineering drawings, contain a wealth of positional and longitudinal (time-referenced) information, available and cheap to produce for those who are constructing Geographic or Land Use Information Systems. If these map products are on stable based material and are not previously handled, the transformation of projection to digitizer coordinate systems would be a matter of determining scale, orientation and translation parameters. In this paper I discuss ways to transform projection coordinates to digitizer values, recognizing that the paper bases are not stable based. Test values are computed and compared for methods and results are interpreted with respect to the geometry of the operation.

Purpose Structure-guided total variation is a recently introduced prior that allows reconstruction of images using knowledge of the location and orientation of edges in a reference image. In this work, we demonstrate the advantages of a variant of structure-guided total variation known as directional total variation (DTV), over traditional total variation (TV), in the context of compressed-sensing reconstruction and super-resolution. Methods We compared TV and DTV in retrospectively undersampled ex vivo diffusion tensor imaging and diffusion spectrum imaging data from healthy, sham, and hypertrophic rat hearts. Results In compressed sensing at an undersampling factor of 8, the RMS error of mean diffusivity and fractional anisotropy relative to the fully sampled ground truth were 44% and 20% lower in DTV compared with TV. In super-resolution, these values were 29% and 14%, respectively. Similarly, we observed improvements in helix angle, transverse angle, sheetlet elevation, and sheetlet azimuth. The RMS error of the diffusion kurtosis in the undersampled data relative to the ground truth was uniformly lower (22% on average) with DTV compared to TV. Conclusion Acquiring one fully sampled non-diffusion-weighted image and 10 diffusion-weighted images at 8× undersampling would result in an 80% net reduction in data needed. We demonstrate efficacy of the DTV algorithm over TV in reducing data sampling requirements, which can be translated into higher apparent resolution and potentially shorter scan times. This method would be equally applicable in diffusion MRI applications outside the heart.

It is shown that when two images are registered by cross-correlating one image with a functional of the other image the minimum registration error variance results when the operation performed cofresponds to that of matched filtering.

Background Quantification of dietary intake is key to the prevention and management of numerous metabolic disorders. Conventional approaches are challenging, laborious, and lack accuracy. The recent advent of depth-sensing smartphones in conjunction with computer vision could facilitate reliable quantification of food intake. Objective The objective of this study was to evaluate the accuracy of a novel smartphone app combining depth-sensing hardware with computer vision to quantify meal macronutrient content using volumetry. Methods The app ran on a smartphone with a built-in depth sensor applying structured light (iPhone X). The app estimated weight, macronutrient (carbohydrate, protein, fat), and energy content of 48 randomly chosen meals (breakfasts, cooked meals, snacks) encompassing 128 food items. The reference weight was generated by weighing individual food items using a precision scale. The study endpoints were (1) error of estimated meal weight, (2) error of estimated meal macronutrient content and energy content, (3) segmentation performance, and (4) processing time. Results In both absolute and relative terms, the mean (SD) absolute errors of the app’s estimates were 35.1 g (42.8 g; relative absolute error: 14.0% [12.2%]) for weight; 5.5 g (5.1 g; relative absolute error: 14.8% [10.9%]) for carbohydrate content; 1.3 g (1.7 g; relative absolute error: 12.3% [12.8%]) for fat content; 2.4 g (5.6 g; relative absolute error: 13.0% [13.8%]) for protein content; and 41.2 kcal (42.5 kcal; relative absolute error: 12.7% [10.8%]) for energy content. Although estimation accuracy was not affected by the viewing angle, the type of meal mattered, with slightly worse performance for cooked meals than for breakfasts and snacks. Segmentation adjustment was required for 7 of the 128 items. Mean (SD) processing time across all meals was 22.9 seconds (8.6 seconds). Conclusions This study evaluated the accuracy of a novel smartphone app with an integrated depth-sensing camera and found highly accurate volume estimation across a broad range of food items. In addition, the system demonstrated high segmentation performance and low processing time, highlighting its usability.

Background Markerless systems to capture body motion require no markers to be attached to the body, thereby improving clinical feasibility and testing time. However, the lack of markers might affect the accuracy of measurements. Objective This study aimed to determine the absolute reliability and concurrent validity of the Kinect system with MotionMetrix software for spatiotemporal variables during running at a comfortable velocity, by comparing data between the combination system and two widely used systems—OptoGait and high-speed video analysis at 1000 Hz. Methods In total, 25 runners followed a running protocol on a treadmill at a speed of 12 km/h. The Kinect+MotionMetrix combination measured spatiotemporal parameters during running (ie, contact time, flight time, step frequency, and step length), which were compared to those obtained from two reference systems. Results Regardless of the system, flight time had the highest coefficients of variation (OptoGait: 16.4%; video analysis: 17.3%; Kinect+MotionMetrix: 23.2%). The rest of the coefficients of variation reported were lower than 8.1%. Correlation analysis showed very high correlations (r>0.8; P0.81) between systems for all the spatiotemporal parameters except contact time, which had lower values. Bland-Altman plots revealed smaller systematic biases and random errors for step frequency and step length and larger systematic biases and random errors for temporal parameters with the Kinect+MotionMetrix system as compared to OptoGait (difference: contact time +3.0%, flight time −7.9%) and high-speed video analysis at 1000 Hz (difference: contact time +4.2%, flight time −11.3%). Accordingly, heteroscedasticity was found between systems for temporal parameters (r2>0.1). Conclusions The results indicate that the Kinect+MotionMetrix combination slightly overestimates contact time and strongly underestimates flight time as compared to the OptoGait system and high-speed video analysis at 1000 Hz. However, it is a valid tool for measuring step frequency and step length when compared to reference systems. Future studies should determine the reliability of this system for determining temporal parameters.

In this paper the problem of accurate edge detection for pulp fibers images is discussed. The images are acquired by the smart CCD camera. Subpixel edge detection is considered that applied in the system to improve the measurement accuracy of pulp fibers. The location of a precise edge is the basis of kink index, kink Angle, curl index and other measurement parameters for the pulp fibers. A new method for subpixel edge detection of the pulp fibers is introduced. Canny operator is used to get the pixel level edge. Each edge point determines five pixels in the gradient direction. Then the least squares fitting is used to locate its sub-pixel edge. The measurement results show that the proposed subpixel edge detection method is valid to improve measurement accuracy for real time measuring the pulp fiber parameters.

We present a system combining optical coherence tomography (OCT) and multispectral imaging (MSI) for coregistered structural imaging and surface color imaging. We first describe and numerically validate an optimization model to guide the selection of the MSI wavelengths and their relative intensities. We then demonstrate the integration of this model into an all-fiber bench-top system. We implement frequency-domain multiplexing for the MSI to enable concurrent acquisition of both OCT and MSI at OCT acquisition rates. Such a system could be implemented in endoscopic practices to provide multimodal, high-resolution imaging of deep organ structures that are currently inaccessible to standard video endoscopes.