RECODE: revision control for digital images

Multimedia Tools and Applications - Revision control is a vital component in the collaborative development of artifacts such as software code and multimedia. While revision control has been widely...     

GASepo-a software solution for quantitative analysis of digital images in Epo doping control

A software has been developed that is aimed at quantitative analysis of images acquired by isoelectric focusing and double blotting procedures used for recombinant erythropoietin doping control. It represents a unified and easy-to-use tool for Epo doping experts in WADA accredited laboratories. It is based on image segmentation philosophy that enables identification of individual bands whose characteristics are needed for evaluation of the Epo doping positivity criteria. Several modules implemented in the GASepo software include an original know how, in particular, the method of robust calculation of the cut-off line, band segmentation and classification algorithms. GASepo is being used in several doping control laboratories worldwide.     

数字图像的固定基稀疏表示方法*

提出了一种采用小波与轮廓波混合的固定基数字图像描述和变换方法,该变换在较粗糙的尺度上采用小波变换,在细节尺度上采用轮廓波变换,既能够克服可分离小波在图像描述方面高频子带方向分辨率较低的缺陷,又能够降低轮廓波变换的计算复杂度。实验结果表明,本方法在具有良好的数字图像逼近能力的同时,还具有很好的消噪结果。     

图像隐写分析现状研究

随着现代隐写术的发展,隐写分析成为信息安全领域一个新的研究热点。对图像隐写分析研究现状进行分析与综述,针对当前隐写分析技术的分类,阐述了隐写分析目的及概念,并重点分析几种常用统计隐写分析算法的原理、适用范围和面临的问题。最后,指出结合各种隐写分析算法,相互取长补短才是今后图像隐写分析发展的方向。     

Correction to: A computationally efficient and scalable key management scheme for access control of media delivery in digital Pay-TV systems

Multimedia Tools and Applications - Tables 1, 3, 4, 5, 6, 7, 8 and the body texts in the original publication contain incorrect symbols. The original article article has been corrected.     

Color reconstruction in digital cameras: optimization for document images

Digital cameras normally sample one color at each pixel. Missing colors are obtained by spatial interpolation, decreasing resolution relative to images acquired with a greyscale sensor. The consequence for document imaging is higher text recognition error rates. This paper introduces the horizontal-vertical regression (HVR) method for document-optimized color reconstruction. HVR exploits a local two-color approximation, making spatial interpolation unnecessary. Comparison with the best alternative reconstruction methods indicates large reductions in error rates for text resulting from HVR, as well as improvements in intermediate color and binary images.Received: 11 June 2003, Accepted: 6 March 2004, Published online: 2 February 2005C. Dance: Correspondence to     

基于数字载体图像分存的零隐写模型

将载体图像分存为多个子图像,组建多载体集,结合图像变换算法,构建基于图像分存的零隐写模型。首先选取初始载体图像,再根据需要分存为一定数量的载体子图像,任意选取一幅或多幅作为实际载体进行特定的图像变换,将隐秘图像分割后寻找图像块与图像变换后载体子图像像素间的相关性,最后传输初始载体图像。接收方以同样方式处理图像并由两者的相关性获取隐秘信息像素值,重组隐秘图像。实验表明该模型增大了隐写容量,提高了隐蔽通信的安全性。     

A fundamental group for greyscale digital images

One of the concepts from topology that has found use in image processing is the so called Fundamental Group of an image. A definition for the digital fundamental group of a binary picture was introduced by Kong in A digital fundamental group [4]. This paper introduces a fundamental group for greyscale images. We also describe Poincaré's classical method for computing a representation of the fundamental group and extend this to work with our greyscale version.     

A hybrid watermarking technique applied to digital images

In this paper, a hybrid watermarking technique applied to digital images is proposed. A watermarking technique is to insert copyright information into digital images that the ownerships can be declared. A fundamental problem for embedding watermarks is that the ways of pursuing transparency and robustness are always trade-off. To solve this problem, a hybrid watermarking technique is proposed to improve the similarity of extracted watermarks. In the proposed technique, the parameters of perceptual lossless ratio (PLR) for two complementary watermark modulations are first derived. Furthermore, a hybrid algorithm based on genetic algorithm (GA) and particle swarm optimization (PSO) is simultaneously performed to find the optimal values of PLR instead of heuristics. From simulation results, it shows the superiority of the proposed hybrid watermarking technique for digital images.     

Web-based digital medical images

Our Web-based interactive system provides efficient and flexible digital medical image data access and manipulation over the Internet, thus offering potential cost savings to the health care system. It has the potential to integrate and associate data from multiple vendors' systems and multiple imaging modalities, not only at an institutional level but also at a regional level. An example of its potential applications is the expert evaluation of images acquired at remote sites in rural areas, which often lack local specialist services.     

Correction to: Granular computing in mosaicing of images from capsule endoscopy

Natural Computing - In the original publication, Acknowledgments was published incorrectly. The correct Acknowledgments is provided in this correction.     

Commercial digital image libraries,digital images and digital discontent

Publications such as consumer magazines rely heavily on image libraries as sources for the images they use in their issues. Traditionally, magazine editorial staff have discussed their image requirements over the telephone with library staff and the library has conducted the search. Many libraries have now developed Web sites and their customers search them for images themselves. A minority have e-commerce capabilities, and enable customers to purchase and download digital images from their sites. This survey found that magazine staff do not often choose to search digital libraries, preferring instead to continue to contact the library by telephone. Most also choose not to buy the use of digital images, but prefer to continue to work with conventional transparencies and slides. The reasons for these preferences, and the reasons they are unlikely to change in the short term, are explored.     

Correction to: A model of digital identity for better information security in e-learning systems

The Journal of Supercomputing -     

A nonparametric-test-based structural similarity measure for digital images

In image processing, image similarity indices evaluate how much structural information is maintained by a processed image in relation to a reference image. Commonly used measures, such as the mean squared error (MSE) and peak signal to noise ratio (PSNR), ignore the spatial information (e.g. redundancy) contained in natural images, which can lead to an inconsistent similarity evaluation from the human visual perception. Recently, a structural similarity measure (SSIM), that quantifies image fidelity through estimation of local correlations scaled by local brightness and contrast comparisons, was introduced by Wang et al. (2004). This correlation-based SSIM outperforms MSE in the similarity assessment of natural images. However, as correlation only measures linear dependence, distortions from multiple sources or nonlinear image processing such as nonlinear filtering can cause SSIM to under- or overestimate the true structural similarity. In this article, we propose a new similarity measure that replaces the correlation and contrast comparisons of SSIM by a term obtained from a nonparametric test that has superior power to capture general dependence, including linear and nonlinear dependence in the conditional mean regression function as a special case. The new similarity measure applied to images from noise contamination, filtering, and watermarking, provides a more consistent image structural fidelity measure than commonly used measures.     

一种块对独立的鲁棒数字图像鉴别方法

随着多媒体数据的广泛使用，其内容的真实性和完整性越来越受到人们的关注，基于内容的多媒体数据鉴别技术成为了一个重要的热点研究领域。根据静态图像的特征，提出了一个用于数字图像的、块对独立的鉴别方法。提取JPEG压缩不变量作为特征，并引入参考块来辅助篡改定位。实验证明，它可以在一定程度上容忍JPEG压缩，对篡改操作敏感，并可以在8^*8像素块的量级上对篡改区域进行精确定位。     

一种数字图像盲增强的新算法

给出一种数字图像盲增强的新算法. 其中源数字图像及其灰度级未知, 已知的仅仅是被噪声污染了的图像. 该算法首先估计密度函数, 然后估计图像的灰度级, 最后去噪声重建图像, 达到图像增强的目的. 仿真例子说明了该算法的有效性.     

Correction of aerosol effects on multi-temporal images acquired with constant viewing angles: Application to Formosat-2 images

This paper presents a new method developed for the atmospheric correction of the images that will be acquired by the Venμs satellite after its launch expected in early 2010. Every two days, the Venμs mission will provide 10 m resolution images of 50 sites, in 12 narrow spectral bands ranging from 415 nm to 910 nm. The sun-synchronous Venμs orbit will have a 2-day repeat cycle, and the images of a given site will always be acquired from the same place, at the same local hour, with constant observation angles. Thanks to these characteristics, the directional effects will be considerably reduced since only the solar angles will slowly vary with time.The algorithm that will be implemented for the atmospheric correction of Venμs data is being developed using both radiative transfer simulations and the actual data acquired by the Formosat-2 satellite. Because of its one-day sun-synchronous repeat cycle, Formosat-2 acquires images with a sun-viewing geometry close to the one Venμs will offer. With this geometry, reflectance time series are free from directional effects on the short term, a feature which reduces the number of unknowns to retrieve. The atmospheric corrections algorithm exploits this feature and the two following assumptions:

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Aerosol optical properties vary quickly with time but slowly with location.

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Surface reflectances vary quickly with location but slowly with time.

Consequently, the top of atmosphere reflectance short term variations (10 to 15 days) are mainly due to the variations of aerosol optical properties, and it is thus possible to use these variations to characterise the atmospheric aerosols and to retrieve surface reflectances.This paper first describes the aerosol inversion method we developed and its results when applied to simulations. In the second part, we show the first tests of the method against three data sets acquired by Formosat-2 images with constant observation angles. Aeronet sun photometers measurements were available on all sites. Formosat-2 estimates of optical thickness compare favourably with Aeronet in situ measurements, leading to a noticeable improvement of the smoothness of time series of surface reflectances after atmospheric correction.     

Deformable Registration of Digital Images

is paper proposes a novel elastic model and presents a deformable registration method based on the model.The method registers images without the need to extract reatures from the images,and therefore works directly on grey-level images.A new similarity metric is given on which the formation of external forces is based.The registration method,taking the coarse-to-fine strategy,constructs external forces in larger scales for the first few iterations to rely more on global evidence,and ther in smaller scales for later iterations to allow local refinements.The stiffness of the elastic body decreases as the process proceeds.To make it widely applicable,the method is not restricted to any type of transformation.The variations between images are thought as general free-form deformations.Because the elastic model designed is linearized,it can be solved very efficiently with high accuracy.The method has been successfully tested on MRI images.It will certainly find other uses such as matching time-varying sequences of pictures for motion analysis,fitting templates into images for non-rigid object recognition,matching stereo images for shape recovery,etc.