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1.
As the basic work of image stitching and object recognition, image registration played an important part in the image processing field. Much previous work in registration accuracy and real-time performance progressed very slowly, especially in registrating images with line feature. An innovative method for image registration based on lines is proposed, it can effectively improve the accuracy and real-time performance of image registration. The line feature can deal with some registration problems where point feature does not work. Our registration process is divided into two parts. The first part determines the rough registration transformation relation between reference image and test image. Then the similarity degree among different transformation and modified non-maximum suppression (MNMS) algorithms are obtained, which produce local optimal solution to optimize the rough registration transformation. The final optimal registration relation can be obtained from two registration parts according to the match scores. The experimental results show that the proposed method makes a more accurate registration relation and performs better in real-time situation.  相似文献   

2.
A Novel and Efficient Method for Iris Automatic Location   总被引:1,自引:0,他引:1  
An efficient and robust iris location algorithm plays a very important role in a real iris recognition system. A novel and efficient iris automatic location method is presented in this study. It includes following two steps mainly: pu- pil location and iris outer boundary location. A digital eye image was divided into many small rectangular blocks with fixed size in the pupil location, and the block with the smallest average intensity was selected as a reference area. Then image binarization was implemented taking the average intensity of the reference area as a threshold. At last the center coordinates and radius of pupil were estimated by extending the reference area to the pupil's boundaries in the binary iris image. In the iris outer location, two local parts of the eye image were selected and transformed into polar coordinates from Cartesian reference. In order to detect the fainter outer boundary of the iris quickly, a novel edge detector was used to locate boundaries of the two parts. The center coordinates and radius of the iris outer boundary can be estimated using the fusion of the locating results of the two local parts and the location information of the pupil. The algorithm was tested on CASIA vl.0 and MMU vl.0 digital eye image databases and experimental results show that the proposed method has satisfying performance and good robustness.  相似文献   

3.
A multipurpose image watermarking technique based on DCT is proposed to notify and protect the copyright of digital products. In order to achieve this objective, the DCT coefficients of each image block are divided into two parts for embedding the visible and invisible watermarks. The visible watermark is embedded in each DC DCT coefficient and most of the AC DCT coefficients of every block, and the invisible watermark in the rest. Based on the characteristics of Human Visual System ( HVS), the embedding strength of the visible watermark is varied in accordance with the underlying content of the host image. The invisible watermark is embedded in a quaternity of midrange frequencies. Experimental results show that the visible watermark is hard to remove and the invisible watermark is robust to common digital signal processing operations.  相似文献   

4.
A two-stage method for image segmentation based on edge and region information is proposed. Different deformation schemes are used at two stages for segmenting the object correctly in image plane. At the first stage, the contour of the model is divided into several segments hierarchically that deform respectively using affine transformation. After the contour is deformed to the approximate boundary of object, a fine match mechanism using statistical information of local region to redefine the external energy of the model is used to make the contour fit the object's boundary exactly. The algorithm is effective, as the hierarchical segmental deformation makes use of the globe and local information of the image, the affine transformation keeps the consistency of the model, and the reformative approaches of computing the internal energy and external energy are proposed to reduce the algorithm complexity. The adaptive method of defining the search area at the second stage makes the model converge quickly. The experimental results indicate that the proposed model is effective and robust to local minima and able to search for concave objects.  相似文献   

5.
The main methods of the second phase quantitative analysis in current material science researches are manual recognition and extracting by using software such as Image Tool and Nano Measurer. The weaknesses such as high labor intensity and low accuracy statistic results exist in these methods. In order to overcome the shortcomings of the current methods, the Ω phase in A1-Cu-Mg-Ag alloy is taken as the research object and an algorithm based on the digital image processing and pattern recognition is proposed and implemented to do the A1 alloy TEM (transmission electron microscope) digital images process and recognize and extract the information of the second phase in the result image automatically. The top-hat transformation of the mathematical morphology, as well as several imaging processing technologies has been used in the proposed algorithm. Thereinto, top-hat transformation is used for elimination of asymmetric illumination and doing Multi-layer filtering to segment Ω phase in the TEM image. The testing results are satisfied, which indicate that the Ω phase with unclear boundary or small size can be recognized by using this method. The omission of these two kinds of Ω phase can be avoided or significantly reduced. More Ω phases would be recognized (growing rate minimum to 2% and maximum to 400% in samples), accuracy of recognition and statistics results would be greatly improved by using this method. And the manual error can be eliminated. The procedure recognizing and making quantitative analysis of information in this method is automatically completed by the software. It can process one image, including recognition and quantitative analysis in 30 min, but the manual method such as using Image Tool or Nano Measurer need 2 h or more. The labor intensity is effectively reduced and the working efficiency is greatly improved.  相似文献   

6.
In order to stabilize the video image sequence, a method of using inertial measurement module to build digital image stabilization system is proposed. Through applying realtime attitude information of the camera that obtained by highprecision attitude sensor to estimate the image motion vector and then to compensate for image, the purpose of stabilizing the image sequence can be achieved. Experiments demonstrate that this method has a high image stabilization precision, and the up to 16 frame/s video output rate completely meets the realtime requirements.  相似文献   

7.
A method of micro-scanning location adaptive calibration was proposed, which was realized by the digital image micro-displacement estimation. With geometric calculation, this calibration method used the displacement estimation of two thermal microscope images to get the size and direction of each scanning location calibration angle. And each location calibration process was repeated according to the offset given by the system beforehand. The comparison experiments of sequence oversampling reconstruction before and after the micro-scanning location calibration were done. The results showed that the calibration method effectively improved the thermal microscope imaging quality.  相似文献   

8.
The hot compression tests using Gleeble 1500 were performed by varying the true strain up to 1.6 (80% reduction) in Nbfree and Nb-microalloyed steels. The effect of Nb addition on the transformation kinetics during deformation of undercooled austenite was investigated. It was found that as compared with Nb-free steel, the transformation incubation period of Nb-bearing steel was prolonged and the transformation kinetics curves parallelly moved to higher strain because of the solute Nb drag effect. Studies on kinetics also showed that the deformation-enhanced ferrite transformation (DEFT) of the two steels were composed of three stages, which can be expressed by the J-M-A equations individually. However, the parameter n related to the mode of nucleation and growth is somewhat different in the first and second stages of the two steels, and the same in the third stage for both the steels corresponding to the nucleation Of retained austenite.  相似文献   

9.
The thesis describes an advanced digital solution to mining digital image monitor system,which makes up the shortage of the traditional mining analog image monitor. It illustrates the system components and how to choose the encoder bandwidth of the system. The problem of image multicast and its solution in LAN are also discussed.  相似文献   

10.
A new method for no-reference image quality assessment based on hybrid fuzzy-genetic technique is proposed. Noise variance and edge sharpness level of the restored image are two basic metrics for assessing the performance of the restoration algorithm, then a fuzzy if-then inference system is developed to combine the two metrics to get a final quality score, and the parameters of the fuzzy membership function are trained with genetic algorithms. Experiments results show that the image quality score correlates well with mean opinion score and the proposed approach is robust and effective.  相似文献   

11.
数字图像的仿射模变换及其周期性   总被引:1,自引:1,他引:0  
以图像信息安全问题为研究背景 ,提出了一类数字图像的仿射模变换 ,讨论了该类变换的周期并给出了证明 ,用实例说明了该类变换在数字图像置乱中的作用  相似文献   

12.
为了对数字图像进行加密,Masaki Miyam等把经典面包师变换推广到截断面包师变换情形;邹建成等给出了三进制下的截断面包师变换的数字图像信息加密方法.本文对这些方法进行了推广,给出了K进制面包师变换的定义,并讨论了其在数字图像加密中的应用.特别是,对基于面包师变换的数字图像加密算法的鲁棒性进行了分析.实验结果表明,这种加密方法能在一定程度上抵抗一些通常的图像攻击,如裁减、压缩和高斯噪音等攻击.  相似文献   

13.
基于拉伸空间变换算法在DSA配准中的应用   总被引:3,自引:0,他引:3  
提出一种基于拉伸的空间变换算法, 首次将其应用于数字减影血管造影术(DSA) 图像配准中以消除运动伪影. 实验结果表明, 与传统线性空间变换算法相比, 采用基于拉伸的空间变换算法配准后的减影图像质量显著改善. 为提高计算速度, 仅对选定的控制点进行块匹配操作, 图像其余像素点基于相邻像素运动位移的连续性, 均由找到的运动位移点经空间变换和灰度插值计算得到. 基于拉伸的空间变换算法可避免采用传统线性空间变换算法所产生的病态解, 属于非线性有理变换. 提出的基于拉伸的空间变换算法简单实用, 可准确有效地确定需估算的运动位移点位置, 且配准后的减影图像质量优于采用线性空间变换算法配准的减影图像质量.  相似文献   

14.
一种基于Internet网安全交易的票据模型   总被引:1,自引:1,他引:0  
给出了用于票据交易的一种安全交易模型,讨论了两种实现的技术方法:数字水印和图像变换技术。这两种技术可用于在线票据交易,解决交易票据传输中的认证问题,具有防欺诈和篡改等特点。  相似文献   

15.
以图像信息安全问题为研究背景,讨论了三维Arnold逆变换和n维Arnold逆变换的周期性,给出了周期的上界估值定理,并用实例说明了三维Arnold逆变换在数字图像置乱中的应用.  相似文献   

16.
With the security problem of image information as the background, some more properties of the period of Arnold transformation of two-dimension were studied by means of introducing a integer sequence. Some new resuits are obtained. Two interesting conjectures on the period of Arnold transformation are given. When making digital images scrambling by Arnold transformation, it is important to know the period of the transformation for the image. As the application of the theory, a new method for computing the periods at last are proposed.  相似文献   

17.
基于光学变换和经典置乱变换的图像复合加密方法   总被引:1,自引:0,他引:1  
图像加密已成为信息安全领域关注的焦点。本文提出了基于光学变换和经典置乱变换相结合的复合加密方法。首先介绍了光学变换中的双随机相位加密方法,其次描述了几何变换中的Arnold变换和混沌变换两种经典置乱加密方法,最后将这三大类加密方法进行组合实现图像复合加密。实验结果表明,本文方法具有更强的安全性。  相似文献   

18.
幻方变换加密数字全息图   总被引:1,自引:0,他引:1  
幻方变换加密数字图像,在某些迭代次数时会泄露原图像的信息.因此,一种改进的方法是将其与其它加密技术结合在一起,如用幻方变换加密数字全息图像.该方法先用信息光学原理将原图生成傅立叶数字全息图,再经幻方变换得到加密图像.在MATLAB上的实验结果表明,幻方变换全息图方法,生成一些类似数字全息图的图像,生成的图像彻底隐去原图的信息.相比单纯使用幻方变换的加密方法,新方法有双重因素控制,有更高的安全性.  相似文献   

19.
Period of arnold transformation and its application in image scrambling   总被引:1,自引:0,他引:1  
With the security problem of image information as the background, some more properties of the period of Arnold transformation of two-dimension were studied by means of introducing a integer sequence. Some new results are obtained. Two interesting conjectures on the period of Arnold transformation are given. When making digital images scrambling by Arnold transformation, it is important to know the period of the transformation for the image. As the application of the theory, a new method for computing the periods at last are proposed. Foundation item: Project (10471020) supported by the National Natural Science Foundation; project (04JJ6028) supported by the Natural Science Foundation of Hunan Province; project (03A002) supported by the Ministry of Education of Hunan Province  相似文献   

20.
针对传统数字图像置乱算法需多次迭代、加密强度不够、密钥空间小和抗攻击性差等问题,基于混沌序列提出一种新的数字图像置乱算法,该算法借助于进制转化和移位改变数字图像的像素值和像素位置,从而使人们无法识别原始图像所表达的真正含义.理论分析和实验结果表明:该算法具有较大的密钥空间,无需迭代,对密钥有很强的敏感性,能改变图像的灰...  相似文献   

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