High capacity data hiding based on multi-directional pixel value differencing and decreased difference expansion

Multimedia Tools and Applications - Data hiding is an important research topic over the years. The PVD based techniques embed secret data into the cover image on the difference between the two...     

Kernel-induced fuzzy clustering of image pixels with an improved differential evolution algorithm

A modified differential evolution (DE) algorithm is presented for clustering the pixels of an image in the gray-scale intensity space. The algorithm requires no prior information about the number of naturally occurring clusters in the image. It uses a kernel induced similarity measure instead of the conventional sum-of-squares distance. Use of the kernel function makes it possible to partition data that is linearly non-separable and non hyper-spherical in the original input space, into homogeneous groups in a transformed high-dimensional feature space. A novel search-variable representation scheme is adopted for selecting the optimal number of clusters from several possible choices. Extensive performance comparison over a test-suite of 10 gray-scale images and objective comparison with manually segmented ground truth indicates that the proposed algorithm has an edge over a few state-of-the-art algorithms for automatic multi-class image segmentation.     

基于边缘像素点分类和插值的图像放大新算法

提出了一种超分辨率图像放大的新方法.根据低分辨率图像上的边缘信息,对初始的一个小图像块依据其对应的低分辨率图像上的边缘点进行分类,并根据此分类对图像块中某些像素点进行重新插值,得到放大的高分辨率图像块.由于对图像中的边缘点进行了特殊的处理,所提出的方法可以提高放大图像的边缘部分的清晰度,克服传统图像放大中图像过于平滑的缺点,对图像进行很好的放大.     

Selective image encryption based on pixels of interest and singular value decomposition

In this paper, an efficient yet simple selective encryption technique is proposed based on Saw-Tooth space filling curve, pixels of interest, non-linear chaotic map and singular value decomposition. The core idea of the proposed scheme is to scramble the pixel positions by the means of Saw-Tooth space filling curve followed by the selection of significant pixels using pixels of interest method. Then the diffusion process is done on the significant pixels using a secret image key obtained from non-linear chaotic map and singular value decomposition. Finally, a reliable decryption process is proposed to construct original image from the encrypted image. The analysis and experimental results show that the proposed scheme can achieve various purposes of selective encryption and is computationally secure.     

A high speed 1000 fps CMOS image sensor with low noise global shutter pixels

A low read noise 8T global shutter pixel for high speed CMOS image sensor is proposed in this paper.The pixel has a pixel level sample-and-hold circuit and an in-pixel amplifier whose gain is larger than one.Using pixel level sample-and-hold circuit,the KTC noise on FD node can be effectively cancelled by correlated double sampling operation.The in-pixel amplifier with a gain larger than one is employed for reducing the pixel level sample-and-hold capacitors thermal noise and their geometric size.A high speed 1000 fps 256×256 CMOS image sensor based on the pixel is implemented in 0.18μm CMOS process.The chip active area is 5 mm×7 mm with a pixel size of 14μm×14μm.The developed sensor achieves a read noise level as low as 14.8e-while attaining a high fill factor of 40%.The full well capacity can contain 30840e-and the resulting signal dynamic range is 66 dB.     

基于边缘点的邻近像素点和去噪的图像修复算法

目前图像修复的基本方法主要有两类:纹理合成的方法和基于偏微分的方法.这两种算法都需要复杂的公式,较难理解和实现,为此提出了一种新的图像修复和去噪方法,该方法不需要先验理论.在定义修复区域像素点的优先度基础上提出了一种邻近像素点的图像修复算法;通过检验每一个像素点的被腐蚀程度提出了一种基于邻近像素点的保留图像对象边缘和细节的图像去噪新方法.算法将图像修复和去噪相结合,达到了更好的修复图像的目的.     

Optimal capacity expansion in the presence of capacity options

This paper studies optimal long-term electric power capacity strategies with capacity options. Gencos (Generation Companies) can sign contracts with Discos (Distribution Companies), where such contracts take the form of capacity options that may or may not be executed by Discos at some prespecified maturation date. Capacity not offered in the options market, or for which options by Discos are not executed, can then be offered in the spot market. The purpose of this paper is to derive the optimal capacities for Gencos in the long-run given full knowledge of the short-term equilibria as characterized by previous literature. We determine the best response strategies for each Genco in the game derived from the short-term outcome resulting from capacity decisions. We then characterize the long-run equilibrium and derive an efficient algorithm to compute it when it exists. This also allows us important insights into the nature of technologies that can survive in the long-run.     

基于平衡区间多小波理论的图像去噪研究

多小波在实际应用中需要对信号进行预滤波,这破坏了多小波的特性.提出了一种基于平衡区间多小波变换的综合闽值图像去噪方法.该方法通过对含噪图像进行区间多小波变换,一方面,克服了单小波变换中无法同时满足正交性和对称性的缺点,且因为区间多小波能够直接适应信号空间,所以不需要像普通小波信号处理那样进行信号的边界延;另一方面,因为平衡区间多小波的平衡性,因此在应用中不需要对图像进行预滤波.将综合阀值处理方法与平衡区间多小波变换相结合,根据多小波分解后的能量分布特性,在不同尺度的子带选择不同的最佳阈值,有效地提高了重构图像质量.实验结果表明,相对于非平衡多小波阈值处理方法,文中的去噪方法在输出信噪比扣主观视觉效果上都有明显改善.     

Strategic level three-stage production distribution planning with capacity expansion

In this paper, we address a strategic planning problem for a three-stage production–distribution network. The problem under consideration is a single-item, multi-supplier, multi-producer, and multi-distributor production–distribution network with deterministic demand. The objective is to minimize the costs associated with production, transportation, and inventory as well as capacity expansion costs over a given time horizon. The limitations are the production capacities of the suppliers and producers, and transportation capacities of the corresponding transportation network. On the other hand, all capacities may be increased at a fixed cost. The problem is formulated as a 0-1 mixed integer programming model. Since the problem is intractable for real life cases efficient relaxation-based heuristics are considered to obtain a good feasible solution.     

Correlation between thermal expansion and heat capacity

The theoretically predicted linear correlation between the volume coefficient of thermal expansion and the thermal heat capacity was investigated for highly symmetrical atomic arrangements. Normalizing the data on these thermodynamic parameters to the Debye temperature gives practically identical curves from zero kelvins to the Debye temperature. This result is consistent with the predicted linear correlation. At temperatures higher than the Debye temperature the normalized values of the thermal expansion are always higher than the normalized value of the heat capacity. The correlation detected has significant computational advantage since it allows calculating the volume coefficient of thermal expansion from one experimental value by using the Debye function.     

基于排序差值脉冲噪声检测的彩色图像滤波方法

提出一种针对彩色图像脉冲噪声进行检测,并根据检测结果利用改进的自适应矢量中值滤波法滤除彩色图像脉冲噪声的方法。试验结果表明,该方法能够明显地减少脉冲噪声检测过程中的噪声漏判数量,有效地去除彩色图像中的脉冲噪声,滤波后不会产生新的颜色,并能较好地保持图像的边缘与细节信息。     

An image detection technique based on morphological edge detection and background differencing for real-time traffic analysis

The real-time vehicle detection from a traffic scene is the major process in image processing based traffic data collection and analysis techniques. The most common algorithm used for real-time vehicle detection is based on background differencing and thresholding operations. The efficiency of this method of image detection is heavily dependent on the background updating and threshold selection techniques. In this paper, a new background updating and a dynamic threshold selection technique is presented. An alternative image detection technique used in image processing is based on edge detection techniques. However, an edge detector extracts the edges of the objects of a scene irrespective of whether it belongs to the background details or the objects. Therefore, to separate these two, extra information is required. We have developed a new image detection method based on background differencing and edge detection techniques, which separates the objects from their backgrounds and works well under various lighting and weather conditions. This image detection technique together with other techniques for calculating traffic parameters e.g. counting number of vehicles, works in real-time on an 80386-based microcomputer operating at a clock speed of 33 MHz.     

Superpixels with contour adherence via label expansion for image decomposition

Neural Computing and Applications - Superpixels could effectively decompose an image into perceptually meaningful partitions, thus facilitating various high-level computer vision tasks. As a...     

Evaluation of image fidelity by means of the fidelogram and level mean-square error

In the present correspondence a method for the representa-tion of image fidelity is proposed and demonstrated by experimental examples. A fidelity measure is also proposed, which is a formal exten-sion of the commonly utilized mean-square error. The characteristics of these fidelity representations are discussed. As a result, it is shown that the representations proposed here are effective, in the sense that they can display clearly the level variance and average levels of the processed image for the standard one, or make it possible to evaluate image fidelity from definite aspects, as compared to existing fidelity representations.     

Low complexity, and high fidelity image compression using fixed threshold method

This paper deals with the design and implementation of an image coding algorithm based on fixed threshold method. Threshold is the Peak Absolute Error (PAE) allowed in the reconstructed image. It has been shown that lossless edges with near-lossless/lossless filled area give a high fidelity images. Results are compared with Set Partitioning In Hierarchical Tree (SPIHT) [A. Said, W.A. Pearlman, A new, fast, and efficient image codec based on set partitioning in hierarchical trees, IEEE Trans. Circ. Syst. Video Technol. 12 (1996) 243-250] method. Experimented results show that the proposed method provides high fidelity images, and it has been shown that these images are visually better than images reconstructed using SPIHT algorithm for the same compression ratio. The execution time of the algorithm is almost half compared to that of the SPIHT algorithm which requires wavelet transform of an image.     

图像隐写容量归一化研究

为解决各类数字图像的隐写容量无法统一衡量的问题,提出了数字图像的最大隐写容量归一化的算法.在阐述最低有效位(LSB)隐写技术的基础上,表明了至多改变一位后的图像的最大嵌入容量小于等于像素数的2倍,实现数字图像的最大隐写容量的归一化,将批量隐写最大容量增加了1倍.在阐述和归纳图像隐写规则后,提出了相应的隐秘信息嵌入和提取算法,并通过实例验证了所提算法的有效性,为数字图像的隐写容量归一化提供了可行的解决途径.     

The activity-based aggregate production planning with capacity expansion in manufacturing systems

This paper builds a mixed integer linear programming (MILP) model to mathematically characterize the problem of aggregate production planning (APP) with capacity expansion in a manufacturing system including multiple activity centers. We use the heuristic based on capacity shifting with linear relaxation to solve the model. Two linear relaxations, i.e., a complete linear relaxation (CLR) on all the integer variables and a partial linear relaxation (PLR) on part of the integer variables are investigated and compared in computational experiments. The computational results show that the heuristic based on the capacity shifting with CLR is very fast but yields low-quality solution whereas the capacity shifting with PLR provides high-quality solutions but at the cost of considerable computational time. As a result, we develop a hybrid heuristic combining beam search with capacity shifting, which is capable of producing a high-quality solution within reasonable computational time. The computational experiment on large-scale problems suggests that when solving a practical activity-based APP model with capacity expansion at the industrial level, the capacity shifting with CLR is preferable, and the beam search heuristic could be subsequently utilized as an alternative if the relaxation gap is larger than the acceptable deviation.     

An integer wavelet transform and pixel value differencing based feature specific hybrid technique for 2D ECG steganography with high payload capacity

Multimedia Tools and Applications - Electrocardiogram (ECG) is essentially a significant physiological signal required in the diagnosis of cardiac disorders. For remote healthcare assistance, ECG...     

A high capacity reversible data hiding scheme with edge prediction and difference expansion

To enhance the embedding capacity of a reversible data hiding system, in this paper, a novel multiple-base lossless scheme based on JPEG-LS pixel value prediction and reversible difference expansion will be presented. The proposed scheme employs a pixel value prediction mechanism to decrease the distortion caused by the hiding of the secret data. In general, the prediction error value tends to be much smaller in smooth areas than in edge areas, and more secret data embedded in smooth areas still meets better stego-image quality. The multiple-base notational system, on the other hand, is applied to increase the payload of the image. With the system, the payload of each pixel, determined by the complexity of its neighboring pixels, can be very different. In addition, the cover image processed by the proposed scheme can be fully recovered without any distortion. Experimental results, as shown in this paper, have demonstrated that the proposed method is capable of hiding more secret data while keeping the stego-image quality degradation imperceptible.