Hybrid image crypto system for secure image communication– A VLSI approach

This work presents permutation and diffusion based hybrid image crypto system in transform domain using combined chaotic maps and Haar Integer Wavelet Transform (HIWT). HIWT is used to transform the plain image and four sub-bands of the image coefficients are encrypted by combined chaotic maps. The combination of two one-dimensional chaotic maps results in better chaotic behavior and generates unpredictable large random sequence that can be used for the encryption of the image. To manage the trade-offs between security, speed and power consumption, the proposed encryption algorithm is modeled in Cyclone II Field Programmable Gate Array (FPGA). The proposed design occupies only 4025 logical elements and takes 0.28 ms for encrypting an image of size 256 × 256. Robustness of the algorithm is estimated using quality metrics including statistical and differential attack analysis. The proposed scheme is resistant to most of the known attacks and is more secure than other image encryption schemes.     

image图形的快速放大

在编写图形处理程序过程中,会遇到图形放大操作,下面介绍一种将image图形通过内存的数据变换放大的方法。放大图形格式为Turbo C中image格式,它的构成为前四个字节为图形的宽和高,后面为屏幕图形数据。图形的放大通过调用enimage()实现。调用enimage()时,buf指向未放大的原图形。调用enimage()后,返回ebuf指向放大后的图形。ebuf所指的图形格式符合image格式,所以可以用putimage()库函数直接进行操     

La didactique de ľimage

The problem addressed in this work is computer assistance to numerical image processing systems. The method used is the implementation of a collection of exercises which form a pedagogical simulation of numerical image processing. The implemented software has two parts: a set of exercises implementing a pedagogical strategy and a user interface. These exercises familiarise the user with the manipulation of numerical data, and introduce him to the working principles of most numerical image-processing systems.     

An image geometry model for METEOSAT†

METEOSAT is a spin-stabilized geostationary satellite which takes Earth images in three spectral channels, infrared, visible and water vapour absorption band. The time-dependent deviations of the satellite from nominal position, attitude and spin speed are described by an image geometry model. A new iterative procedure for refined attitude determination is used. The attitude is derived from northern and southern polar horizon scan limits which are extracted from infrared image data. The geometry model provides a deformation vector field which relates the ideal reference image to the actual image. The actual image is then mapped to the reference image by the nearest-neighbour rectification process.     

A proof of image Euler Number formula

1 Introduction In digital image, topological invariant refers to the value, which can keep the image characteristics unchanged when the image flexes freely just like the elastic rubber. The Euler Number is one of the topological characteristics, which can…     

Electron image processing: 1978–1980

Computer processing of electron microscope images has developed and expanded rapidly since the preceding bibliography in this series appeared [P. W. Hawkes, Computer Graphics and Image Processing, 8, 1978, 406–446]. The publications listed are grouped into the following classes: general works; image formation; linear processing; nonlinear problems; image handling; and high resolution and lattice imagery.     

多功能一体机——Canon image CLASS MF3112

如果你还在抱怨打印，复印的速度不够快，那么拥有20ppm引擎的MF3112一定不会让你失望，这是一款主要面向SOHO类用户设计的产品，它集成了打印，扫描与复印三种功能于一身．作为MF3110的升级型号．MF3112在外观和控制面板方面并没有很大变化，依然是蓝色的控制面板与白色的机身相捂配．外形小巧、紧凑．它的各项性能指标和我们之前测试过的MF3110也非常接近，即便是如此．其飞快的打印速度仍给我们留下了深刻的印象．     

Diffusion–substitution based gray image encryption scheme

In this paper, an encryption algorithm for gray images using a secret key of 128-bits size is proposed. Initially, visual quality of image is degraded by the mixing process. Resultant image is partitioned into key dependent dynamic blocks and, further, these blocks are passed through key dependent diffusion and substitution processes. Total sixteen rounds are used in the encryption algorithm. Proposed technique is simple to implement and has high encryption rate. Simulation experiment results have been given to validate the high security features and effectiveness of proposed system.     

Hyperspectral image super-resolution with spectral–spatial network

ABSTRACT

The super-resolution problem for hyperspectral images is currently one of the most challenging topics in remote sensing. Increasingly effective methods have been presented to solve this ill-posed problem under certain circumstances. In this article, we propose a new approach named the spectral–spatial network (SSN), which can effectively increase spatial resolution while keeping spectral information. The SSN consists of two sections: a spatial section and a spectral section that contribute to enhancing spatial resolution and preserving spectral information, respectively. The spatial section is proposed to learn end-to-end mapping between single-band images, from low-resolution and high-resolution hyperspectral images. In this section, we enhance the traditional sub-pixel convolutional layer by adding a maximum variance principle that can realize nonlinear fitting through piecewise linearization. The spectral section aims to fine-tune spectral caves to keep the spectral signature with a spectral angle error loss function. In order to make the SSN converge quickly, we also develop a corresponding three-step training method. The experimental results on two databases, with both indoor and outdoor scenes, show that our proposed method performs better than the existing state-of-the-art methods.     

Multiscale stochastic hierarchical image segmentation by spectral clustering

This paper proposes a sampling based hierarchical approach for solving the computational demands of the spectral clustering methods when applied to the problem of image segmentation. The authors first define the distance between a pixel and a cluster, and then derive a new theorem to estimate the number of samples needed for clustering. Finally, by introducing a scale parameter into the simi- larity function, a novel spectral clustering based image segmentation method has been developed. An important characteristic of the approach is that in the course of image segmentation one needs not only to tune the scale parameter to merge the small size clusters or split the large size clusters but also take samples from the data set at the different scales. The multiscale and stochastic nature makes it feasible to apply the method to very large grouping problem. In addition, it also makes the segmentation compute in time that is linear in the size of the image. The experimental results on various synthetic and real world images show the effective- ness of the approach.     

Fuzzy segmentation for object‐based image classification

This Letter proposes an object‐based image classification procedure which is based on fuzzy image‐regions instead of crisp image‐objects. The approach has three stages: (a) fuzzification in which fuzzy image‐regions are developed, resulting in a set of images whose digital values express the degree of membership of each pixel to target land‐cover classes; (b) feature analysis in which contextual properties of fuzzy image‐regions are quantified; and (c) defuzzification in which fuzzy image‐regions are allocated to target land‐cover classes. The proposed procedure is implemented using automated statistical techniques that require very little user interaction. The results indicate that fuzzy segmentation‐based methods produce acceptable thematic accuracy and could represent a viable alternative to current crisp image segmentation approaches.     

Leveraging community metadata for multimodal image?ranking

Searching for relevant images given a query term is an important task in nowadays large-scale community databases. The image ranking approach presented in this work represents an image collection as a graph that is built using a multimodal similarity measure based on visual features and user tags. We perform a random walk on this graph to find the most common images. Further we discuss several scalability issues of the proposed approach and show how in this framework queries can be answered fast. Experimental results validate the effectiveness of the presented algorithm.     

Cryptanalysis of an embedded systems’ image encryption

Multimedia Tools and Applications - Recently, a new image encryption-scheme for embedded systems based on continuous third-order hyperbolic sine chaotic system, has been proposed. The...     

A chaos-based image encryption algorithm using alternate structure

Combined with two chaotic maps, a novel alternate structure is applied to image cryptosystem. In proposed algorithm, a general cat-map is used for permutation and diffusion, as well as the OCML (one-way coupled map lattice), which is applied for substitution. These two methods are operated alternately in every round of encryption process, where two subkeys employed in different chaotic maps are generated through the masterkey spreading. Decryption has the same structure with the encryption algorithm, but the masterkey in each round should be reversely ordered in decryption. The cryptanalysis shows that the proposed algorithm bears good immunities to many forms of attacks. Moreover, the algorithm features high execution speed and compact program, which is suitable for various software and hardware applications.     

Transreceiving of encrypted medical image – a cognitive approach

Multimedia Tools and Applications - Recently, there is an increasing demand for efficient and secure transreception of medical images in telemedicine applications. Though a fixed spectrum is...     

Diffusion filtering in image processing based on wavelet transform

Nonlinear diffusion filtering is a method for images or signals processing based on partial differential equations (PDEs). Its basic idea is to establish a suitable PDE model in the time-space domain and obtain a family of its solutions as the filtered ve…     

浅谈如何使用SQL中的image和text数据

SQL中的image和text类型的数据带给用户很多便利,但具体使用时常常会遇到许多问题,那么该如何解决呢,我们可以用两个命令提示符下的命令bcp和textcopy来解决。     

Fast computation of 3D Meixner’s invariant moments using 3D image cuboid representation for 3D image classification

Multimedia Tools and Applications - In this paper, we propose a new fast computation method of 3D discrete orthogonal invariant moments of Meixner. This proposed method is based on two fundamental...     

Remote sensing image fusion based on Bayesian linear estimation

A new remote sensing image fusion method based on statistical parameter estimation is proposed in this paper. More specially, Bayesian linear estimation (BLE) is applied to observation models between remote sensing images with different spa- tial and spectral resolutions. The proposed method only estimates the mean vector and covariance matrix of the high-resolution multispectral (MS) images, instead of assuming the joint distribution between the panchromatic (PAN) image and low-resolution multispectral image. Furthermore, the proposed method can enhance the spatial resolution of several principal components of MS images, while the traditional Principal Component Analysis (PCA) method is limited to enhance only the first principal component. Experimental results with real MS images and PAN image of Landsat ETM demonstrate that the proposed method performs better than traditional methods based on statistical parameter estimation, PCA-based method and wavelet-based method.