Keratocytes are fibroblast-like cells that maintain the optical clarity and the overall health of the cornea. The ability to measure precisely their density and spatial distribution in the cornea is important for the ...
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Keratocytes are fibroblast-like cells that maintain the optical clarity and the overall health of the cornea. The ability to measure precisely their density and spatial distribution in the cornea is important for the understanding of corneal healing processes and the diagnostics of some corneal disorders. A novel computerized approach to detection and counting of keratocyte cells from ultra high resolution optical coherence tomography (UHR-OCT) images of the human corneal stroma is presented. The corneal OCT data is first processed using a state-of-the-art despeckling algorithm to reduce the effect of speckle on detection accuracy. A thresholding strategy is then employed to allow for improved delineation of keratocyte cells by suppressing similarly shaped features in the data, followed by a second-order moment analysis to identify potential cell nuclei candidates. Finally, a local extrema strategy is used to refine the candidates to determine the locations and the number of keratocyte cells. Cell density distribution analysis was carried in 3D UHR-OCT images of the human corneal stroma, acquired in-vivo. The cell density results obtained using the proposed novel approach correlate well with previous work on computerized keratocyte cell counting from confocal microscopy images of human cornea. (C) 2011 Optical Society of America
We present, in this paper, a comparative analysis of the letters in Times New Roman (TNR), Courier New (CN) and Arial (Ar) font types in plain and italic style and the effects of five foreground/background color combi...
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We present, in this paper, a comparative analysis of the letters in Times New Roman (TNR), Courier New (CN) and Arial (Ar) font types in plain and italic style and the effects of five foreground/background color combinations using an invariant digital correlation system with a nonlinear filter with k = 0.3. The evaluation of the output plane with this filter is given by the peak-to-correlation energy (PCE) metric. The results show that the letters in TNR font have a better mean PCE value when compared with the CN and Ar fonts. This result is in agreement with some studies on text legibility and for readability where the reaction time (RT) of some participant individuals reading a text is measured. We conclude that the PCE metric is proportional to 1/RT.
In the wrapped phase map of the 3D object containing the height discontinuities, this paper develops an enhanced noise detection scheme to enable the three types of noise, the speckle noise, the residual noise, and th...
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ISBN:
(纸本)9780819479129
In the wrapped phase map of the 3D object containing the height discontinuities, this paper develops an enhanced noise detection scheme to enable the three types of noise, the speckle noise, the residual noise, and the noise at the lateral surface of height discontinuities, to be efficiently and simultaneously detected with a greater degree of precision. Since any threshold of this scheme is related to the number of noise and does not influence the phase jumps, the application with filtering operations enables the edges of the phase jumps without smearing and the application with the phase unwrapping algorithms enables the unwrapping path to avoid the positions of the noise, especially, at the height discontinuities.
This paper addresses concealed object detection by passive millimeter wave (MMW) imaging. Passive MMW imaging penetrates into clothing to capture metal and man-made objects. In this paper, we propose a multi-level exp...
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This paper addresses concealed object detection by passive millimeter wave (MMW) imaging. Passive MMW imaging penetrates into clothing to capture metal and man-made objects. In this paper, we propose a multi-level expectation maximization (EM) method to separate the concealed object from the body area. The performance is evaluated by the average probability of error. We will show that the proposed EM processes segments the object area more accurately than the conventional EM method.
We present a parallel and memory-efficient iterative algorithm based on 2D first-order regular graphs. For an M x N regular graph with L iterations, a carefully chosen computation order can reduce the memory resources...
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We present a parallel and memory-efficient iterative algorithm based on 2D first-order regular graphs. For an M x N regular graph with L iterations, a carefully chosen computation order can reduce the memory resources from O(MN) to O(ML). This scheme can achieve a memory reduction of 4 to 27 times in typical computation-intensive problems such as stereo and motion. (c) 2007 Optical Society of America
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