共查询到20条相似文献，搜索用时 15 毫秒
1.
A logistic map controlled secure arithmetic coding is proposed, the Logistic map is used to control the order of the symbols in the model and change the probabilities of the symbols, which is applied to the image encryption. The proposed scheme makes the image transmit more secure and comfortably on the Internet, and that is done at little expense in terms of coding efficiency. In the coding process, it ensures the uniformity of the model being changed by the chaotic sequence, thus to meet the security requirements of image compression. The algorithm can be applied to any arithmetic codec based on multimedia data including video, image and audio. Its most strength compared with other cipher mode is that, there is a significant reduction in the redundancy of information during the compression process, and it is robust when attempting to estimate the information of the image and discovering the key. The scheme can effectively resist differential analyses from both cryptography and coding. 相似文献
2.
H, 264 is the new standard for video coding, it can save 64.46%, 48, 80% and 38.62% bit-rate compared with that of MPEG-2, H. 263 HLP and MPEG-4 ASP respectively under the same decoded picture quality, But the high encoding efficiency is at the cost of heavily increased computational complexity. The multi-prediction macroblock mode search and rate-distortion optimization mode decision that achieve high encoding efficiency are introduced firstly. Then experiment researches are performed to analyze their effect on encoding efficiency. Results show that these two kinds of technique can only achieve slightly improvement on encoding efficiency, but computational complexity increases heavily. This provides an important reference for the parameters selection when H. 264 is used in the practical application of video coding. 相似文献
3.
基于压缩编码的加密方式能够同时完成加密和压缩的功能,通过压缩减少了信息的冗余,同时引入加密使对试图推测出明文信息和找到密钥的攻击具有非常好的鲁棒性。提出了一种基于随机区间置换的安全算术编码,在编码过程中通过随机密钥保证图像压缩编码的安全性,且不影响编码的效率,使其方便在网络中安全传输。实验结果和安全性分析表明该安全算术编码有较好的安全性和加密效率。 相似文献
4.
Digital watermarking is an effective method to provide copyright protection for digital media. A blind image- adaptive watermarking algorithm based on DCT domain is presented. The algorithm selects adaptively the step size of quantization to embed the watermark bits by modifying DC components via the human visual system model and local characteristics of image; at the same time some AC components of the blocks with less perceptual capacity are also modified to embed the same watermark bits by using quantization. Thus the relation between robustness and imperceptibility can be well balanced. The algorithm recovers the watermark without any reference to the original image. Compared with the similar algorithm reported in the literature, this method can give better image quality and is better robust against noise and commonly used image processing techniques. 相似文献
5.
With the analysis of the principle of time-recursive filter, the authors find that the nature of time-recursive filter is Weighted Mean Low-Pass filter and the relationship between filter coefficients and SNR and the artifact arising from the area where motion can not be tracked. One approach based on Automatic Control Method is proposed to solve the artifacts problem during the process of filtering and the authors designed the corresponding hardware based on FPGA and software respectively. The experimental results show that the time-recursive filtering is good at digital video image denoising and reduces the random noise of digital camera system. 相似文献
6.
Brownian Motion is one of the important characteristics of submicron particles.On the basis of observatiorl for Brownian motion of particles,the authors present a medel to describethis physieal process by usin g fractal theory a nd this medel is proved to be valid in theory.Throughfurther an alyzing,we establish the relationship between fractal characteristics and particle sizeparameters.Combining image signal processing technique,particle size information can be obtainedby computing fractal dimension values,and then a new method for particle sking will be developedinfuture. 相似文献
7.
A Context Model of Wavelet Coefficients for Image Compression 总被引：1，自引：0，他引：1
Through the combination of the idea of the linear prediction used in the GlicBawls coding scheme and the idea of the quantization taken in the CALIC coding scheme to reduce the number of contexts, a new context model of wavelet coefficients for image compression is proposed. Wavelet coefficients are encoded by the arithmetic encoder, with the contexts formed by quantizing linear prediction values. Experimental results show that the model achieves higher lossless compression rate of image than lossless SPIHT and lossless EBCOT used in JPEG2000. In addition, by exploiting the multiresolution property of wavelet, the model can compress the transformed image for progressive resolution and earn higher compression rate for each scale of the image than EBCOT. 相似文献
8.
Aiming at the problem of link fault restoration in ASON, an improved equalizing routing algorithm (ERA) is introduced to proportion the load at the routing phase. In order to solve the easy blocking problem for the network without wavelength converter because of the wavelength continuity constraint, the algorithm WRCA is proposed at the wavelength assignment phase. This algorithm is realized by adding collision detection object (CDO) in the path message of the resource reservation protocol with traffic engineering extension (RSVP TE). Depending on the value of the CD flag, different wavelength selection strategies are applied at the destination node, and the blocks resulting from wavelength reservation collision are reduced. The simulation experiments compare four wavelength assignment algorithms with the same routing algorithm ERA. The results show that compared with the traditional first fit algorithm (FF) and random fit algorithm (RD), the FF and RD employing CD scheme can effectively reduce the blocking ratio of the whole network, and enhance the practical applicability of the restoration algorithms. 相似文献
9.
YANG zhi-ping 《保鲜与加工》2001,(3):110-113
To enhance quality of image processing, it is demanded that coding algorithm should be simplified and the speed of image processing should be faster,and information loss on image compressed should be minimum.Adaptive segmentation is given for image which to be processed.Region coding is combined with threshold coding.Adaptation to mixture transform coding is fulfilled.Results of simulation shows that with this method coding loss witch images are compressed is mined and quantity of image processing is good. 相似文献
10.
As a kind of data compression technique of high efficiency, arithmetic coding is widely used in image compressing. This paper introduces the adaptive binary arithmetic coding used in the new international standard of still image compression named jpeg2000. The implementation of arithmetic coding depends on high power digital signal processor.Fast adaptive binary arithmetic coding and optimized assembly program design are discussed, and its practicability and efficiency are proved.It also can be used in other fields that need compressing data. 相似文献
11.
An image edge detection algorithm in fuzzy domain is proposed, which combines adaptive fuzzy enhancement and multi direction fuzzy morphology to detect the edges of fuzzy image. The adaptive fuzzy enhancement method enhances the fuzzy image within blocks with sliding windows to avoid losses of the real edges resulting from enhancing with single threshold for the whole image and lead strong adaptive ability to image region variance. The multi direction fuzzy mathematical morphology operates on the enhanced fuzzy image with structure elements of multiple different directions to extract the real edges with directionality and restrain non directional noise. Experiments show the algorithm can detect fuzzy image edge effectively with strong antinoise ability. 相似文献
12.
Fractal geometry is a branch of applied mathmatics in 1975,and it is used to describe the surface character of irregular bodies. This paper applies fractal demension to study the micropores structures of lime sand concrete,and concludes that it can be used to describe the microp-ores. Their radii are less than 100A. The fractal demensions of lime sand concrete are measured by MlP(mean indicated pressure) technique. The results have shown that the stronger the autoclaving schedules,the less the fractal demensions of lime sand concrete;the larger the water solid ratio(W/S),the larger the fractal demensions,and the calcium silicate ratio(C/S) has the effect on the fractal demensions of lime sand concrete. A pore structure parameter, mean pore radius is also proposed. 相似文献
13.
为了解决彩色人脸识别中色彩信息易受光照影响的问题,提出一种基于光强倒数色度空间(IICS)的彩色人脸图像预处理方法。本方法首先将图像均匀地分割成子块;将每个图像块变换为IICS空间中的一个二维数据集,并根据数据集的线性分布特性估计图像块的光照颜色;然后对全部图像块的光照估计进行颜色直方图统计,根据直方图对分块估计的结果进行合并;最后,利用估计得到的光照和对角模型将图像光照校正到标准白光下,用于人脸识别。在AR和FERET人脸库上的实验表明,通过引入本光照预处理,有效增强了彩色人脸识别方法对光照变化的鲁棒性,提高了识别精度。 相似文献
14.
Li Bo Xiong Xuandong Zhu Qingsheng 《保鲜与加工》1997,(6):77-79
A new still picture compression coding algorithm,WH JPEG algorithm have been proposed due to JPEG baseline system having problem.Advantages of the algorithm include:remove blocking effect,higher compression rate,satisfactory multiform demand by contorlling number of layer. 相似文献
15.
DICOM3.0 standard is complex and rich in contents. Aiming at the difficulty of software design, a programming method of generating DICOM image file in the high frequency X ray machine is proposed. The data structure of DICOM file is analyzed, and then the programming method of generating DICOM image files is introduced in detail. For the proposed method, a template array of the data structure is constructed to save the eigenvalues, transfer syntax, pixel data and so on of the image. All kinds of the data are stored in the DICOM file successively. The programming method can not only transform a BMP file into a DICOM file, but also transform a JPEG file into a DICOM file. It strictly follows DICOM 3.0 protocol. The generated DICOM files can be displayed with the DICOM file browsing software ezDICOM. The programming design was based on VC++6.0. 相似文献
16.
Sieve grading of cereal kernels by means of quantitative image analysis
In former investigations several possibilities to apply computerized quantitative image analysis (CQJA) in the field of crop science have been reported. In the present studies applicability of this technique have been tested to accurately determine sieve grading of barley kernels. Accordingly, CQJA seems to be appropriate for measuring and processing digitalized image information of the respective length and thickness of grain kernels both, at high velocity and precision, and it can be done at any classification of kernel sizes. Contamination of the cereals by broken grain and/or other non-grain material can be discriminated by integrating threshold levels of minimum and maximum diameters respectively. It is argued that major advantages of the proposed automated CQJA-equipment could be (1) control of sieve grading and calibration processes of seeds and (2) sieve grading of the kernels of individual ears for breeding purposes. 相似文献
In former investigations several possibilities to apply computerized quantitative image analysis (CQJA) in the field of crop science have been reported. In the present studies applicability of this technique have been tested to accurately determine sieve grading of barley kernels. Accordingly, CQJA seems to be appropriate for measuring and processing digitalized image information of the respective length and thickness of grain kernels both, at high velocity and precision, and it can be done at any classification of kernel sizes. Contamination of the cereals by broken grain and/or other non-grain material can be discriminated by integrating threshold levels of minimum and maximum diameters respectively. It is argued that major advantages of the proposed automated CQJA-equipment could be (1) control of sieve grading and calibration processes of seeds and (2) sieve grading of the kernels of individual ears for breeding purposes. 相似文献
17.
LUO Xiao-gang PENG Cheng-lin ZHENG Xiao-lin LI Qing-huiistry of Education College of Bioengineering Chongqing University Chongqing Chin 《保鲜与加工》2003,(12):51-54
We research fractal characteristics of ECG signal, and find that it is logarithmic linear relationship between the boxes number covering signal and box scale. It is shown that ECG signal have some characteristics. Further more, we discover that fractal dimensions at QRS site are higher than others when using a time windows to detect signal. Based on this foundation, we raise a location algorithm of QRS waves which is based on fractal boxes dimension detection methods. The application results of this algorithm show that it can get rid of noise in ECG effectively with high speed, so this algorithm can be used in real time detection of ECG signal. 相似文献
18.
Liao Xiaoyun Lei Wenyu 《保鲜与加工》1999,(1):18-23
A new analysis method for machining surface profile error is presented in this paper.The linear regression and nonlinear regression are first applied respectively,and then the Weierstrass Mandebrot fractal function is used to obtain the fractal parameters of machining profiles.A minimal parameter set which depicts the machining surface geometric precision is set up,and the surface profile can be reconstructed using these parameters,and an analysis method for part performance and its tolerance structure is proposed.Examples are provided to illustrate the method is feasible and effective. 相似文献
19.
基于图像处理的玉米分形维数及其种植密度效应评价 总被引：3，自引：0，他引：3
以玉米品种强盛49为试材,采用数字图像处理技术和计盒维数方法,研究了种植密度对株型的影响。结果表明,随着种植密度增加(2.4~7.8株 m-2),植株的分形维数(FD值)从1.192逐渐下降至1.163。随着生育进程的推进,所有种植密度下FD值都呈现出先上升后下降的趋势。分形维数与株高、光合叶源和生物产量有一定的相关性。FD值是定量描述玉米株型的一种重要新性状,在作物长势与长相等生长诊断研究中有广泛的应用前景。 相似文献
20.
Adaptive regularization can select different parameters based on the features of local areas in an image, which can differentiate the edges and noise in an image flexibly. An adaptive graph regularization is proposed based on graph spectral theory and adaptive regularization, which uses the Non local means to generate the weighting function of graph. The adaptive graph regularization equation is used to filter the noisy image. Simulation results show that the proposed method can effectively remove the noise and is superior to other graph theory based partial differential equation methods. 相似文献