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Iterative image reconstruction for positron emission tomography (PET) can improve image quality by using spatial regularization that penalizes image intensity difference between neighboring pixels. The most commonly used quadratic penalty often over-smoothes edges and small objects in reconstructed images. Non-quadratic penalties can preserve edges but may introduce piece-wise constant blocky artifacts...
It has long been recognised that a wireless communication system can be more efficient if link-layer parameters such as modulation order, symbol rate and packet size, are (adaptively) optimised. A common optimising criterion is to maximise spectral efficiency (bits per second per Hertz (bps/Hertz)) subject to a very low bit-error constraint. But a packet-oriented criterion for link adaptation seems...
We present a self-assessing image-based motion compensation method for coronary roadmapping in fluoroscopic images. Extending our previous work on respiratory motion compensation, we introduce kernel-based nonparametric data analysis in this work to better characterize the objective function involved in motion estimation, which leads to two new improvements in motion compensation. First, through mode...
This paper describes a novel approach to the connected component labeling problem, derived from two fast labeling algorithms, Wu et al. and Park et al. We propose a method that improves over existing divide and conquer methods. We propose two new methods - First, hierarchical (coarse to fine) label propagation from various sub images. Second, the recursive boundary labeling method is only one neighbor...
In sub-wavelength lithography, traditional resolution enhancement techniques (e.g., OPC) cannot guarantee the optimality of the mask. In this paper, we present a novel inverse lithography method to solve the mask optimization problem. Recognizing that when formulated on a pixel-by-pixel basis with partially coherent optical models, the problem is a large-scale nonlinear optimization problem, we cast...
In TLC satellite systems operating in the Ka-band, the dynamic control of the on-board antenna pattern is recognized as an effective countermeasure against the atmospheric attenuations due to rain, water vapour, etc. The on-board available power is better exploited when distributed on the service area by privileging the sub-regions requiring, at a given time, more power to counteract the local attenuation...
Phased array antennas with a desired symmetric scan range about broadside usually are designed with array elements that have a corresponding symmetry. However, this appears to be unnecessarily restrictive. We 1) show that symmetric scan performance normally is maintained even with asymmetric array elements, and 2) compare conventional, symmetric patches with asymmetric patches, which have no E-plane...
The problem of compositing a high dynamic range (HDR) image for display on a standard low dynamic range device involves matte-based fusion of multiple images captured with different camera exposures, followed by a suitable tone mapping of the fused HDR image. The fused image should represent the entire scene in a clear, well-exposed manner by bringing the under- and over-exposed regions from the input...
One important recent application of image registration has been in the estimation of global motion parameters for object-based video coding. A limitation of current global motion estimation approaches is the additional complexity of the gradient-descent optimization that is typically required to calculate the optimal set of global motion parameters. In this paper we propose a new low-complexity algorithm...
Template matching is a widely used technique in many of image processing and machine vision applications. In this paper we propose a new as well as a fast and reliable template matching algorithm which is invariant to Rotation, Scale, Translation and Brightness (RSTB) changes. For this purpose, we adopt the idea of ring projection transform (RPT) of image. In the proposed algorithm, two novel suggestions...
In this paper, we describe a new optimization method which we call Multiple Birth and Cut (MBC). It combines the recently developed Multiple Birth and Death (MBD) algorithm and the Graph-Cut algorithm. MBD and MBC optimization methods are applied to the energy minimization of an object based model, the marked point process. We compare the MBC to the MBD showing the advantages and disadvantages, where...
In this paper, an improved ant colony optimization based approach for image edge detection is proposed. The algorithm use ant colony clustering approach to extract edge feature. The approach set the heuristics information function and the initial cluster, thus avoiding the search blindness which carried out by traditional ant colony algorithm. And a series of simulation experiments demonstrate the...
A fast recognition algorithm of weed is achieved and improved on the DSP of DM6437 with C64+ core in this paper. The algorithm is able to identify weeds between the crop rows with information of the locations and areas. Meanwhile, it is optimized based on the C64+ core. And it takes about 10.9ms to handle a weed image with 320*240 pixels, which meets the requirement of real-time application.
This paper proposed a whole new design for RV40(realvideo40) video decoder from FFmpeg(fast forward Moving Picture Experts Group),which is in lack of the ability to decode smoothly when decoding a period of high bit rate frames within some video streams. The design specially optimized the sub pixel interpolation algorithm, which is the core of motion compensation. The design uses detailed, different...
To improve compression capacity, motion compensation (MC) is utilized in H.264, which includes 6-tap FIR for 1/2-pel interpolation and 2-tap filter for 1/4-pel interpolation. MC uses up most decoding time, and is the expensive part of H.264 decoder. Some consumer electronics, such as smartphones, may not have enough processing capability to decode high definition video program in real time. MC must...
End-to-end distortion estimation is critical to effective error-resilient video coding. The recursive optimal per-pixel estimate (ROPE) is a known approach to compute up to second moments of decoder-reconstructed pixels, and thereby optimally estimate the distortion. ROPE accurately accounts for encoding/decoding operations that are recursive in the pixel domain, and their interaction with packet...
An implementation of the nonlinear iterative partial least squares algorithm (NIPALS) was used as a test case for use of OpenCL for computation on a general purpose graphics processing unit (GPGPU) cluster using MPI. Timing results are shown along with results of a model of time required per iteration for defined problem sizes. Various steps in optimization of the code are discussed, moving from use...
In this paper, we present a novel re-texturing approach using intrinsic video. Our approach begins with indicating the regions of interests by contour-aware layer segmentation. Then, the intrinsic video (including reflectance and illumination components) within the segmented region is recovered by our weighted energy optimization. After that, we compute the normals for the re-textured region, and...
Recently, a model-based depth estimation technique has been proposed, which estimates surface model parameters by means of Hooke-Jeeves optimization. Assuming a parametric surface model, the parameters best explaining the perspective changes of the surface between different views are estimated. This constitutes a fitting of models directly into stereo images, which is in contrast to the usual approach...
This paper compares several camera calibration methods on the estimation of specific extrinsic and intrinsic parameters. Good estimates of the chosen parameters, rotation and radial lens distortion are essential to increase the accuracy of quantitative measurements and to accurately stitch single field-of-view-based images together. The parameters are obtained using two selected methods on different...
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