基于小波域的模糊化区域竞争模型的图像分割方法

本文中提出了一种基于小波变换的模糊化区域竞 争图像分割算法。该算法利用小波变 换在纹理分类 的优越性,在模糊化区域竞争算法的框架下对图像实施非抽样小波变换,建立起基于小波域 的统计特征参 数,并根据此特征参数构造能量函数。在算法求解过程中,通过采用快速迭代算法加快算法 求解的速度。 本文提出的图像分割算法可以有效地降低信噪比的敏感性,有效地解决模糊图像分割问题。 实验结果表明, 本文提出的分割方法在分割质量和速度上比经典的主动轮廓模型和模糊化区域竟争分割算法 更具有优越性。     

基于小波域多状态隐马尔科夫树模型的自适应文本图像分割算法

本文针对文本图像首先提出了一种基于小波域多状态隐马尔科夫树模型的自适应文本图像分割算法(Context-Adapted wavelet-domain Hidden Markov Tree,简称为CAHMT),该算法具有较高的分割质量和较低的计算复杂度.其次,为了进一步提高CAHMT算法分割的效果,将该算法与微分算子、尺度系数相结合提出了两种新的文本图像分割算法.最后通过实例阐明了这些算法的有效性.     

基于CDF9-7小波和自适应Otsu算法的视频字幕分割

提出了一种基于CDF9-7小波和自适应Otsu算法的视频图像字幕分割算法。首先从视频中截取视频图像,并对其进行灰度化等预处理,其次对预处理后的图像进行CDF9-7小波变换,获取其水平和垂直的高频分量HH,然后使用自适应Otsu算法分割出该高频分量图像中的字幕区域。实验表明,该算法分割效果良好,具有一定的鲁棒性和自适应性。以这些区域为基础,可以进一步完成诸如视频字幕识别等图像分析、理解和识别操作。     

基于新闻文本图像的鲁棒水印算法

在新闻文本图像中,现有的水印算法没有将表达文本部分的区域与其他背景区域进行区分,并且对二值水印图像嵌入时只在单通道嵌入导致鲁棒性不高。针对以上问题,提出基于新闻文本图像的鲁棒水印算法。首先将新闻文本图像进行大津阈值分割（OSTU）,将文本与背景区域区分开,选择文本区域进行嵌入加深对重要信息的版权保护;接着将文本图像Cr和Cb通道的文本区域进行离散小波变换（DWT）后,利用主成分分析（PCA）进行能量集中并计算各主成分贡献率,通过比较贡献率来选择嵌入的主成分;最后对主成分及水印图像进行奇异值分解（SVD）完成水印嵌入。经过实验表明,嵌入水印图像在面对滤波等大多数常规攻击的NC值都在0.99以上,表明该算法有较强的鲁棒性,同时该算法在嵌入水印后图像的PSNR均值为45.66 dB,保证了不可感知性。     

基于Gabor小波变换的彩色图像分割

本文提出了一种基于Gabor小波变换的彩色图像分割方法，首先对彩色图像进行Gabor小波变换，然后进行特征提取，并采用动态聚类K-均值算法进行分类，最后得到图像分割的结果。实验和分析表明，该方法对于彩色自然图像的分割具有较好的效果。     

基于模糊推理的电气设备红外图像分割

使用模糊理论处理电气设备红外图像分割的不确定性，提出了一种基于模糊推理的电气设备红外图像分割算法。首先分别利用电气设备红外图像故障区域的像素灰度、像素点与图像质心的马氏距离以及图像膨胀操作定义了强度特征、全局故障可能性特征和局部灰度特征；然后根据特征的模糊语言值制定了27条模糊规则，设计了一种模糊推理红外图像分割算法；最后，从主观和客观评价指标上将算法与传统Otsu算法和FCM算法进行了对比。实验表明，该算法的分割精度和误分割率比其他两种算法都有一定的改善，同时该算法能够滤除图像中具有高亮度的干扰区域，对具有小亮度差和小面积故障区域的红外图像有较好的分割效果。     

一种基于图像分层的标牌压印字符分割方法

由于标牌图像的低质量特点,经典的图像分割算法无法达到理想的分割效果.为此,本文提出了一种适用于标牌图像特点的分割算法.首先根据标牌图像灰度分布的特点将图像从最暗层到最亮层进行分层;对最暗层图像进行自适应二值化可得到标牌图像中的印刷文本像继而,基于连通域对印刷文本图像进行分析确定其所在区域;最后将确定的印刷字符区域从始图像中去除,可得到目标区域,即仅含有压印凹凸字符区域的目标图像.经过对大量标牌图进行分割实验证明,本算法是一种适用于标牌压印凹凸字符分割的有效算法.     

一种基于自适应标记与区域间近邻传播聚类的分水岭图像分割算法

分水岭算法是一种高效的图像分割算法,能够准确地对图像进行基于区域的分割,但是存在易过分割的问题.为此本文提出一种改进的分水岭算法：首先,对彩色图像进行频谱包络滤波并计算彩色梯度获得梯度图像,再采取一种自适应设定参数的H-minima技术,对梯度图像的极小值区域进行标记;然后,对已标记极小值区域的梯度图像进行分水岭分割;最后,计算分水岭分割所得各区域的颜色矩,作为该区域的颜色特征,并对这些区域进行近邻传播聚类获得分割结果.通过与近年来其它改进的分水岭算法和采用聚类的图像分割算法实验比较,本文所提算法能更加有效地抑制过分割,提高分割准确率,具有良好的自适应性和鲁棒性.     

基于“图像”分割的小波脊线提取算法

针对传统脊线提取算法不能同时兼顾速度和精度的问题,本文提出了一种新的基于“图像”分割的小波脊线提取算法。对渐近性信号进行连续小波变换以后,模值较大的小波系数往往集中在时间-尺度平面上几个分散的区域,将小波系数模值矩阵看作一个“图像”,对其分割,再对分割得到的每个区域确定其极值位置可得到小波脊线。仿真实验表明：本文算法不仅较传统脊线算法在精度和效率都有所提高,在信号去噪和信号分离中也表现良好。     

基于直方图极大值准则可变参数图像阈值分割方法

提出了一种基于直方图极大值准更则图像阈值分割方法，通过调节参数可对多类图像进行分割。阉值分割是实时图像处理首选的分割算法。本文通过一维灰度直方图确定极大值，从而获得图像中多个目标区域和背景区域阉值，分割出多个区域，将每个区域赋为不同的灰度级，根据具体所要分割的目标再进行分割。实验证明该方法分割效果较好，分割速度快，实时性较好。     

Foreground text segmentation in complex color document images using Gabor filters

Extraction of foreground contents in complex background document images is very difficult as background texture, color and foreground font, size, color, tilt are not known in advance. In this work, we propose a RGB color model for the input of complex color document images. An algorithm to detect the text regions using Gabor filters followed by extraction of text using color feature luminance is developed too. The proposed approach consists of three stages. Based on the Gabor features, the candidate image segments containing text are detected in stage-1. Because of complex background, certain amount of high frequency non-text objects in the background are also detected as text objects in stage-1. In stage-2, certain amount of false text objects is dropped by performing the connected component analysis. In stage-3, the image segments containing textual information, which are obtained from the previous stage are binarized to extract the foreground text. The color feature luminance is extracted from the input color document image. The threshold value is derived automatically using this color feature. The proposed approach handles both printed and handwritten color document images with foreground text in any color, font, size and orientation. For experimental evaluations, we have considered a variety of document images having non-uniform/uniform textured and multicolored background. Performance of segmentation of foreground text is evaluated on a commercially available OCR. Evaluation results show better recognition accuracy of foreground characters in the processed document images against unprocessed document images.     

Binarization of color document images via luminance and saturationcolor features

This paper presents a novel binarization algorithm for color document images. Conventional thresholding methods do not produce satisfactory binarization results for documents with close or mixed foreground colors and background colors. Initially, statistical image features are extracted from the luminance distribution. Then, a decision-tree based binarization method is proposed, which selects various color features to binarize color document images. First, if the document image colors are concentrated within a limited range, saturation is employed. Second, if the image foreground colors are significant, luminance is adopted. Third, if the image background colors are concentrated within a limited range, luminance is also applied. Fourth, if the total number of pixels with low luminance (less than 60) is limited, saturation is applied; else both luminance and saturation are employed. Our experiments include 519 color images, most of which are uniform invoice and name-card document images. The proposed binarization method generates better results than other available methods in shape and connected-component measurements. Also, the binarization method obtains higher recognition accuracy in a commercial OCR system than other comparable methods.     

Multifunctional Dielectric Metasurfaces Consisting of Color Holograms Encoded into Color Printed Images

A hologram records the wavefront of light from an object, but it is usually not an image itself, and looks unintelligible under diffuse ambient light. Here a new paradigm to encode a color hologram onto a color printed image is experimentally demonstrated. The printed image can be directly viewed under white light illumination, while a low‐crosstalk color holographic image can be seen when the device is illuminated with red (R), green (G), and blue (B) laser beams. The device is a dielectric metasurface that consists of titanium dioxide (TiO₂) cones on a glass substrate. The dimensions of the TiO₂ cones are chosen to allow them to support visible‐wavelength resonances, thereby producing the desired reflection spectra and thus the color printed image. The detour phase method is furthermore used to encode the hologram into the metasurface. The approach is conceptually different from previously demonstrated color printed images or holograms and presents opportunities for optical document security and data storage applications.     

An Authentication Technique for Image/Legal Document (ATILD)

The paper presents an image/legal-document authentication and secures message transmission technique by embedding message/image/message-digest into color images. Image authentication is done by embedding message/image within the image pixels of source image. Legal document authentication is done by embedding the authenticating image and self generated message digest (generated from signed document part) into the image part of the legal document. The position of insertion is chosen within each byte of source image using XOR operation between upper three bits of each source byte and k where k is any number from 0 to 7. Three bits of authenticating message/image/message-digest are embedded in each byte of source image. Fabrication process starts with the dimension of authenticating image followed by message digest (MD) and ends by embedding the content of authenticating message/image. To enhance the security further a layer has also been fabricated by XOR operation of the embedded image with another self generated MD key obtained from the source image. The decoding is done by applying the reverse algorithm. Experimental results are tested with the aid of Histogram analysis, noise analysis, standard deviation computation and PSNR, IF, MSE analysis of the source and embedded image and has been compared with popular existing steganographic algorithms like S-Tools where the proposed ATILD is capable to hide large volume of data than S-Tools and shows better performance. The proposed ATILD technique also shows high amount of sustainability against various attacks.     

基于BMP文件信息隐藏技术的探讨

信息隐藏技术的出现和发展,为信息安全的研究扩展了一个新的领域.编程时采用最低有效位算法(LSB算法)将秘密信息嵌入作为栽体的24位真彩色BMP图像中,并对算法进行了两点改进:将控制信息也当作秘密信息嵌入到BMP文件的图像数据区;嵌入信息时,与载体信息进行了一步运算.     

Robust non-blind color video watermarking using QR decomposition and entropy analysis

Issues such as content identification, document and image security, audience measurement, ownership and copyright among others can be settled by the use of digital watermarking. Many recent video watermarking methods show drops in visual quality of the sequences. The present work addresses the aforementioned issue by introducing a robust and imperceptible non-blind color video frame watermarking algorithm. The method divides frames into moving and non-moving parts. The non-moving part of each color channel is processed separately using a block-based watermarking scheme. Blocks with an entropy lower than the average entropy of all blocks are subject to a further process for embedding the watermark image. Finally a watermarked frame is generated by adding moving parts to it. Several signal processing attacks are applied to each watermarked frame in order to perform experiments and are compared with some recent algorithms. Experimental results show that the proposed scheme is imperceptible and robust against common signal processing attacks.     

基于Radon变换的倾斜彩色图像自动矫正方法

在图像处理系统中,通过采集设备获得的图像如彩色扫描文档不可避免地会出现倾斜现象,虽然文档图像处理技术已经取得很多进展,但是,对于倾斜图像的矫正还存在困难.本文根据图像的结构特征 ,给出了基于Canny边缘检测和Radon变换相结合的算法,根据Radon变换取得的倾斜角度进行图像的倾斜矫正.实验表明,算法对彩色图像进行自动矫正是准确、高效的.     

A Document Image Model and Estimation Algorithm for Optimized JPEG Decompression

The JPEG standard is one of the most prevalent image compression schemes in use today. While JPEG was designed for use with natural images, it is also widely used for the encoding of raster documents. Unfortunately, JPEG's characteristic blocking and ringing artifacts can severely degrade the quality of text and graphics in complex documents. We propose a JPEG decompression algorithm which is designed to produce substantially higher quality images from the same standard JPEG encodings. The method works by incorporating a document image model into the decoding process which accounts for the wide variety of content in modern complex color documents. The method works by first segmenting the JPEG encoded document into regions corresponding to background, text, and picture content. The regions corresponding to text and background are then decoded using maximum a posteriori (MAP) estimation. Most importantly, the MAP reconstruction of the text regions uses a model which accounts for the spatial characteristics of text and graphics. Our experimental comparisons to the baseline JPEG decoding as well as to three other decoding schemes, demonstrate that our method substantially improves the quality of decoded images, both visually and as measured by PSNR.     

The Implementation of an Experimental Teleteaching System with Enhanced Document Image Display

1　ＩｎｔｒｏｄｕｃｔｉｏｎＷｉｔｈｔｈｅｒａｐｉｄｄｅｖｅｌｏｐｍｅｎｔｏｆｃｏｍｐｕｔｅｒ,ｃｏｍ ｍｕｎｉｃａｔｉｏｎ ,ａｎｄｍｕｌｔｉｍｅｄｉａｔｅｃｈｎｏｌｏｇｙ ,ｄｉｓｔａｎｃｅｅ ｄｕｃａｔｉｏｎｈａｓｂｅｅｎｐｌａｙｉｎｇｍｏｒｅａｎｄｍｏｒｅｉｍｐｏｒｔａｎｔｒｏｌｅｉｎｍｏｄｅｒｎｓｏｃｉｅｔｙ[1～ 5] .Ｎｏｒｍａｌｌｙ ,ｃｏｌｌｅｇｅｓａｎｄｕｎｉｖｅｒｓｉｔｉｅｓｉｎｓｔａｌｌｔｈｅｉｒｄｉｓｔａｎｃｅｅｄｕｃａｔｉｏｎｓｙｓｔｅｍｓｉｎｆｉｘｅｄｃｌａｓｓｒｏｏｍｓａｔｄｉ…     

基于小波和色彩传递的夜视图像彩色融合技术

提出一种基于小波和色彩传递的夜视图像的彩色融合方法,使观察者更容易获取图像的场景信息。结合红外图像和微光图像各自的特点,利用NRL法把红外图像和微光图像映射到彩色空间形成假彩色图像(源图像),然后通过小波变换对源图像和参考图像进行多分辨率分解,计算不同分辨率下的均值和标准方差,将各分量根据参考图像和源图像的标准方差比进行缩放,把参考图像的色彩分布传递给源图像。实验结果表明,通过与传统方法的比较,本文算法不仅获得真实场景色彩,还可以提高图像的细节信息,改善场景感知。