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1.
An adaptive algorithm for removing false ridges, bridges and filling gaps in binary fingerprint images based on morphological operations is presented. A novel procedure for structuring elements design based on the specific fingerprint characteristic is described. Using the images from FVC2000 database, we have compared our method proposed here with the approach proposed by other ones. The Experimental results have demonstrated the efficiency of our method. 相似文献
2.
A Novel Adaptive Approach to Process Binary Fingerprint Images Using Directional Morphological Operations 下载免费PDF全文
Jin Qi 《电子科技学刊:英文版》2009,7(2):129-131
An adaptive algorithm for removing false ridges, bridges and filling gaps in binary fingerprint images based on morphological operations is presented. A novel procedure for structuring elements design based on the specific fingerprint characteristic is described. Using the images from FVC2000 database, we have compared our method proposed here with the approach proposed by other ones. The Experimental results have demonstrated the efficiency of our method. 相似文献
3.
稀疏表达的自适应遥感图像融合算法 总被引:1,自引:0,他引:1
本文提出一种基于稀疏表达的图像融合算法。该算法利用稀疏系数中的非零元素所对应的基向量作为图像特征,首先分离相同基向量和相异基向量,然后采用加权求和算法合并相对应的稀疏系数,并重构得到融合图像。该算法对相同特征和相异特征分别进行融合,克服了融合图像中相异特征清晰度下降的问题。并且由于稀疏表达具有很好的去噪功能,本文算法也可以同时进行图像融合和去噪。通过与4种流行的融合算法比较,本文算法得到较好的视觉效果。 相似文献
4.
自适应径向巴特沃思核时频表示 总被引:3,自引:0,他引:3
二次时频表示的性能由其核函数决定,一种固定的核只能适应于某些类型的信号,由此出现了核可随时间与信号变化的自适应核时频表示。本文采用径向为巴特沃思滤波器形式的核构造了一种自适应核时频表示。实验结果表明,对于不同类型的信号它都有好的性能。 相似文献
5.
An adaptive approach to two-dimensional tree encoding of images is presented based upon the use of spatial masking concepts. Specifically, we make use of an adaptive encoding filter of the smoothing variety whose smoothing action is controlled by the local visibility of the encoding noise. The approach is an attempt to obtain an optimum compromise between slope overload and granular noise characteristics associated with existing two-dimensional tree encoding schemes. We demonstrate that this adaptive approach can provide improved overall image coding performance, both objectively and subjectively, compared to existing tree encoding schemes at a reduced order of complexity. The subjective improvements are clear and striking to the eye. 相似文献
6.
7.
当视频传输中出现不能恢复的误码或丢包时,在接收端就要使用差错掩盖技术对损坏的视频进行掩藏。该文提出了一种基于模糊聚类和网格变形的自适应差错掩盖方法,使得错误恢复效果提高。该方法首先用基于时-空的模糊聚类块匹配方法补偿平移运动场景中的块丢失,然后如果检测出丢失块所在的空间有旋转、缩放等复杂运动,则用基于网格变形的方法进行补偿。实验结果表明其PSNR值比Luigi(2001)的BMA-MBW方法平均提高约1.5dB,比传统的基于块匹配的方法平均提高约3.5dB。 相似文献
8.
A Cross-Layer Routing Scheme Using Adaptive Retransmission Strategy for Wireless Mesh Networks 总被引:1,自引:1,他引:0
In this paper, we develop a link quality-based adaptive adjustment mechanism of the MAC maximum retransmission count to reduce
collision probability of wireless Mesh networks. Based on statistics acquired in the link layer and the retransmission strategy,
a multi-metric cross-layer on-demand routing scheme is proposed for wireless Mesh networks. The proposed scheme uses information
such as available link bandwidth, node residual load rate and transmission efficiency of a path adequately to cross-layer
routing. The network layer can adaptively select an optimal path to deliver packets based on the acquired statistics of the
MAC layer. Extensive simulation results demonstrate that the proposed scheme can reduce link failure probability, improve
network throughput, and decrease the end-to-end delay effectively. 相似文献
9.
Sergio D. Servetto Yong Rui Kannan Ramchandran Thomas S. Huang 《The Journal of VLSI Signal Processing》1998,20(1-2):137-150
We study the problem of representing images within a multimedia Database Management System (DBMS), in order to support fast retrieval operations without compromising storage efficiency. To achieve this goal, we propose new image coding techniques which combine a wavelet representation, embedded coding of the wavelet coefficients, and segmentation of image-domain regions in the wavelet domain. A bitstream is generated in which each image region is encoded independently of other regions, without having to explicitly store information describing the regions. Simulation results show that our proposed algorithms achieve coding performance which compares favorably, both perceptually and objectively, to that achieved using state-of-the-art image/video coding techniques while additionally providing region-based support. 相似文献
10.
《Signal Processing, IEEE Transactions on》2006,54(10):3702-3711
This paper presents novel approaches to parallelize context-based adaptive binary arithmetic coders (CABACs). Two new parallelized CABACs (or PCABACs) are presented and the methods described. These coders are designed by modifying commonly used binary multiplication-free arithmetic coders. One utilizes linear approximation and simplifies the hardware by assuming that the less probable symbol probability is almost the same while performing the en/decoding (referred to as QL-coder). Another codec applies table lookup technique and achieves parallelism with a parallelized probability model (referred to as QT-coder). QL-coder is improved from the IBM Q-coder, and the QT-coder is improved from the CABAC used in H.264 video compression standard. Throughput, in both coders, is significantly increased after parallelization. A fast interval search method is also proposed. 相似文献
11.
This paper presents several adaptive linear predictive coding techniques based upon extension of recursive ladder filters to two and three dimensions (2-D/3-D). A 2-D quarter-plane autoregressive ladder filter is developed using a least square criterion in an exact recursive fashion. The 2-D recursive ladder filter is extended to a 3-D case which can adaptively track the variation of both spatial and temporal changes of moving images. Using the 2-D/3-D ladder filters and a previous frame predictor, two types of adaptive predictor-control schemes are proposed in which the prediction error at each pel can be obtained at or close to a minimum level. We also investigate several modifications of the basic encoding methods. Performance of the 2D/3-D ladder filters, their adaptive control schemes, and variations in coding methods are evaluated by computer simulations on two real sequences and compared to the results of motion compensation and frame differential coders. As a validity test of the ladder filters developed, the error signals for the different predictors are compared and the visual quality of output images is verified. 相似文献
12.
《电子学报:英文版》2017,(6):1227-1232
Noise reduction is a very important topic in image processing. We propose a new method to deal with the case where the noisy image has different noise levels in different regions. The main idea is to segment automatically the noisy image into several sub-images so that each sub-image has approximately the same noise level. We perform Block matching 3D filtering (BM3D) to these subimages in order to obtain denoised sub-images. We then merge sub-images together and enhance the discontinuous regions between the sub-images by performing BM3D again on small image patches. Our experimental results show the effectiveness of this proposed method in terms of Peak signal to noise ratio (PSNR) when compared with the bivariate wavelet shrinkage and the standard BM3D method. In addition to Gaussian white noise, our method performs better than the bivariate wavelet shrinkage and the standard BM3D method even for signal dependent noise. 相似文献
13.
《IEEE transactions on image processing》2008,17(12):2356-2367
14.
Recently, the ability of anti-fading measures to reduce the outage which occurs on digital microwave radio links has been the subject of considerable study. Ideal and nonideal adaptive equalization in both the time and frequency domain have been evaluated for nondiversity reception using various performance criteria. Ideal adaptive equalization and space diversity reception have been considered using a recently published model of multipath fading on space diversity radio channels. In this paper, we determine the outage of 16-QAM and 64-QAM digital radio systems using adaptive slope equalization, finite-tap decision feedback equalization, and switched space diversity reception. The outage is evaluated by computing the probability of occurrence of those channel realizations which cause the bit error rate to exceed a critical value. The dependence of the outage prediction on the equalization method and the outage defining criterion is investigated by also considering ideal adaptive equalization and a signal-to-distortion ratio, respectively. 相似文献
15.
自适应速率选择是影响无线Mesh网性能的关键问题。提出了一种基于动态解调门限的速率自适应选择算法,该算法通过统计传输速率进行速率选择,能够针对不同信道环境对每种调制速率所需最小信噪比门限进行自动调整。同时,采用跨层设计思想,采用路由协议广播报文作为MESH设备间传输信噪比信息的载体,从而能够根据信噪比和传输成功率信息得到信道环境下的最佳发送速率。实际测试结果表明,所提算法能够在较短时间内选择出最佳速率,而且具有较低的抖动和稳定的吞吐量。 相似文献
16.
An efficient adaptive encoding technique using a new implementation of the Fast Discrete Cosine Transform (FDCT) for bandwidth compression of monochrome and color images is described. Practical system application is attained by maintaining a balance between complexity of implementation and performance. FDCT sub-blocks are sorted into four classes according to level of image activity, measured by the total ac energy within each sub-block. Adaptivity is provided by distributing bits between classes, favoring higher levels of activity over lower levels. Excellent performance is demonstrated in terms of mean square error and direct comparison of original and reconstructed images. Results are presented for both noiseless and noisy transmission at a total rate of 1 bit and 0.5 bit per pixel for a monochrome image and for a total rate of 2 bits and 1 bit per pixel for a color image. In every case the total bit rate includes all overhead required for image reconstruction and bit protection. 相似文献
17.
H. I. Ashiba K. H. Awadalla S. M. El-Halfawy F. E. Abd El-Samie 《Circuits, Systems, and Signal Processing》2011,30(3):543-551
This paper presents an adaptive block-by-block least squares (LS) algorithm for the interpolation of infrared (IR) images.
The suggested algorithm is based on the segmentation of the low resolution (LR) image into overlapping blocks and the interpolation
of each block, separately. The purpose of the overlapping is to avoid edge effects between blocks. An iterative implementation
of the proposed algorithm, which considers the image acquisition model, is used for the minimization of the estimation error
in each block. A weight matrix of moderate dimensions is estimated in a small number of iterations to interpolate each block.
This proposed algorithm avoids the large computational complexity resulting from the matrices of large dimensions required
to interpolate the image as a whole. The performance of the proposed algorithm is compared with the standard as well as the
warped distance optimal interpolation of maximal order with minimal support (O-MOMS) algorithm from the peak signal-to-noise
ratio (PSNR) point of view. Numerical results reveal the superiority of the proposed LS algorithm to the cubic O-MOMS algorithm. 相似文献
18.
文章提出了一种适用H.264标准的自适应算术编码器的VLSI实现方案,它对算术编码的结构做了改进,用查表代替了乘法操作,并采用流水线结构实现,获得了较高的吞吐速率.在采用Verilog语言对编码模块进行描述后,用ALTEAR公司的现场可编程门阵列(FPGA)进行仿真验证.实验表明,这种流水线结构的算术编码器能够获得较高的编码速度. 相似文献
19.
Karystinos G.N. Pados D.A. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2007,53(9):3075-3080
Over the real/complex field, the spreading code that maximizes the signal-to-interference-plus-noise ratio (SINR) at the output of the maximum-SINR linear filter is the minimum-eigenvalue eigenvector of the interference autocovariance matrix. In the context of binary spreading codes, the maximization problem is NP-hard with complexity exponential in the code length. A new method for the optimization of binary spreading codes under a rank-2 approximation of the inverse interference autocovariance matrix is presented where the rank-2-optimal binary code is obtained in lower than quadratic complexity. Significant SINR performance improvement is demonstrated over the common binary hard-limited eigenvector design which is shown to be equivalent to the rank-1-optimal solution. 相似文献