algorithms are presented for the adaptive processing of binary images of silhouettes of the human hand obtained by means of color-brightness filters. These algorithms are based on the use of a combination of elementar...
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algorithms are presented for the adaptive processing of binary images of silhouettes of the human hand obtained by means of color-brightness filters. These algorithms are based on the use of a combination of elementary morphological operations that take into account the direction of the fingers. algorithms are presented for removing noise on binary images that are adapted to the result of the operation of a color filter, and a method is presented for filling internal contours of a silhouette of the hand in order to remove grouped marking errors. The experimental results show that the proposed image-processing method increases the probability of successful detection, tracking of the hand, and recognition of gestures. (C) 2014 Optical Society of America.
Most structured illumination microscopes use a physical or synthetic grating that is projected into the sample plane to generate a periodic illumination pattern. Albeit simple and cost-effective, this arrangement hamp...
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Most structured illumination microscopes use a physical or synthetic grating that is projected into the sample plane to generate a periodic illumination pattern. Albeit simple and cost-effective, this arrangement hampers fast or multi-color acquisition, which is a critical requirement for time-lapse imaging of cellular and sub-cellular dynamics. In this study, we designed and implemented an interferometric approach allowing large-field, fast, dual-color imaging at an isotropic 100-nm resolution based on a sub-diffraction fringe pattern generated by the interference of two colliding evanescent waves. Our all-mirror-based system generates illumination patterns of arbitrary orientation and period, limited only by the illumination aperture (NA = 1.45), the response time of a fast, piezo-driven tip-tilt mirror (10 ms) and the available fluorescence signal. At low mu W laser powers suitable for long-period observation of life cells and with a camera exposure time of 20 ms, our system permits the acquisition of super-resolved 50 mu m by 50 mu m images at 3.3 Hz. The possibility it offers for rapidly adjusting the pattern between images is particularly advantageous for experiments that require multi-scale and multi-color information. We demonstrate the performance of our instrument by imaging mitochondrial dynamics in cultured cortical astrocytes. As an illustration of dual-color excitation dual-color detection, we also resolve interaction sites between near-membrane mitochondria and the endoplasmic reticulum. Our TIRF-SIM microscope provides a versatile, compact and cost-effective arrangement for super-resolution imaging, allowing the investigation of co-localization and dynamic interactions between organelles - important questions in both cell biology and neurophysiology (C) 2013 Optical Society of America
We present a widefield structured illumination microscope for imaging surgical tumor margins in situ. The impact of frequency and turbidity on optical section thickness and SNR was characterized to determine the optim...
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ISBN:
(纸本)9781557529732
We present a widefield structured illumination microscope for imaging surgical tumor margins in situ. The impact of frequency and turbidity on optical section thickness and SNR was characterized to determine the optimal imaging frequency.
We investigated image processing algorithms of the original infrared glass flaw image. Using the Laplacian edge enhancement following LSD （Line Segment Detector） algorithm, we can get a good flaw image very consiste...
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We investigated image processing algorithms of the original infrared glass flaw image. Using the Laplacian edge enhancement following LSD （Line Segment Detector） algorithm, we can get a good flaw image very consistent with the original one. This study is very helpful to further enhance the infrared glass flaw inspection technique.
Fish-eye cameras are widely used on many occasions due to their ultrawide field of view (about 180 degrees). In this paper, we present a high-precision two-step calibration method to calibrate fish-eye cameras. The tw...
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Fish-eye cameras are widely used on many occasions due to their ultrawide field of view (about 180 degrees). In this paper, we present a high-precision two-step calibration method to calibrate fish-eye cameras. The two steps are the global polynomial projection model fitting and local line-fitting calibration optimization. In the first step, we obtain the projection model of the fish-eye camera and apply a quartic polynomial to fit the projection model over the entire image. In the second step, the fish-eye image is partitioned into several sections and line fitting is adopted in each section in order to further reduce the residual error of the first calibration step. Experiments show that the new method is able to correct the distortion of the real scene image well. In addition, its average reprojection error is 0.15 pixel better than 0.40 pixel of the general projection model described. The reason that higher calibration precision is obtained is that this method not only considers the global projection model of the fish-eye camera but also considers the local characteristics, such as small tangential distortion and asymmetry. (C) 2013 Optical Society of America
We present an algorithm to process images of reflected Placido rings captured by a commercial videokeratoscope. Raw data are obtained with no Cartesian-to-polar-coordinate conversion, thus avoiding interpolation and a...
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We present an algorithm to process images of reflected Placido rings captured by a commercial videokeratoscope. Raw data are obtained with no Cartesian-to-polar-coordinate conversion, thus avoiding interpolation and associated numerical artifacts. The method provides a characteristic equation for the device and is able to process around 6 times more corneal data than the commercial software. Our proposal allows complete control over the whole process from the capture of corneal images until the computation of curvature radii. (C) 2013 Optical Society of America
Plenoptic imaging systems are often used for applications like refocusing, multimodal imaging, and multiview imaging. However, their resolution is limited to the number of lenslets. In this paper we investigate paraxi...
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Plenoptic imaging systems are often used for applications like refocusing, multimodal imaging, and multiview imaging. However, their resolution is limited to the number of lenslets. In this paper we investigate paraxial, incoherent, plenoptic image formation, and develop a method to recover some of the resolution for the case of a two-dimensional (2D) in-focus object. This enables the recovery of a conventional-resolution, 2D image from the data captured in a plenoptic system. We show simulation results for a plenoptic system with a known response and Gaussian sensor noise. (C) 2013 Optical Society of America
This paper investigates an adaptive method of dim small target detection in infrared images with a complex background. We analyze in depth the characteristics of the background, the target, and the noise in the gray i...
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This paper investigates an adaptive method of dim small target detection in infrared images with a complex background. We analyze in depth the characteristics of the background, the target, and the noise in the gray intensity, space and frequency domain of the images. The modified top-hat transformation using interrelated structuring elements is adopted to adaptively detect the darker and the brighter targets and greatly suppress the cluttered background. Lateral pattern inhibition enhances the local contrast ratio and simultaneously identifies the targets of interest. The automatic threshold is used to enhance real dim targets in the cluttered background. A simulation based on the proposed algorithm is carried out and the results prove that the algorithm is effective and valid. (C) 2013 Optical Society of America
Three-dimensional (3D) surface topographic analysis, measurement, and assessment techniques have raised great interest not only among researchers but also among industrial users. Many industrial processes and applicat...
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Three-dimensional (3D) surface topographic analysis, measurement, and assessment techniques have raised great interest not only among researchers but also among industrial users. Many industrial processes and applications are directly influenced by the small-scale roughness of surface finishes. This paper describes the development and implementation of a noncontact, three-dimensional, microtopography measuring system. The instrument is formed by combining a modified light-sectioning microscope subsystem with a computer subsystem. In particular, optical system characteristics of the light-sectioning microscope are investigated, and a textured steel sheet is measured to demonstrate good practical outcomes. Details of measuring processes and image processing algorithms are provided, such as procedures for measurement, image edge extraction, and 3D topography reconstruction. After the 3D topography of the measured surface has been reconstructed, the topography field description parameters are calculated. A standard roughness block was used for calibration of the surface microtopography measuring system. Results obtained showed the measurement method output has good agreement with the actual asperity (unevenness or roughness) of the surface. The computer subsystem is used to process and control asperity measurements and image generation, and for image acquisition and presentation. (C) 2012 Optical Society of America
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