利用质心模式统计进行图像纹理分析

基于区域质心具有某些与人类视觉相适应的性质,提出一种新的纹理分析算法——质心模式统计法(StatisticsofCentroidPattern,SCP)。该算法通过对纹理基元质心分布位置与特点进行分析得到纹理的基元特征,该特征可以反映基元内灰度、能量等分布信息。然后通过对基元特征进行加权投影统计,得到图像的方向性、对比度等纹理特征,这些特征可以更好的适应人类视觉特性。将该算法应用于Brodatz图像库的图像检索,实验结果表明,SCP在查准率上比差分矩阵和纹理谱分别提高10.26%和26.66%,取得了更好的检索效果,可以对图像纹理进行更为精确的描述与分析。     

基于字符串匹配技术的图像检索算法

为提高图像检索的效果,提出了一种基于字符串匹配技术的图像检索算法。该算法根据人眼的视觉特性及方块编码(BTC)的原理首先对图像进行分割,构造对表征图像内容有意义的图像特征。在此基础上,根据字符出现的概率对字符表征意义的重要性,把图像特征动态映射成字符串形式,然后采用字符串匹配技术进行图像检索。该算法不仅利用了图像中的边缘及纹理分布,而且将字符串匹配技术引入到图像检索中,在提高检索率的同时又加快了检索速度。实验结果表明,该算法具有较高的检索效率。     

基于纹理特征的钢丝绳图像分割方法

针对复杂背景下钢丝绳图像难以准确分割的问题,提出一种新的基于纹理特征的图像分割方法.首先,采用局部二进制模式(Local Binary Pattern,LBP)特征直方图的一阶熵、二阶熵作为LBP特征的统计测度,降低LBP特征的维数.同时选用边缘密度作为纹理描述的特征之一,弥补LBP算子提取纹理特征不足,抗干扰能力差的缺点.然后以上述纹理特征构成特征矢量,采用模糊C-均值(Fuzzy C-Mean,FCM聚类算法进行聚类分割.在实验中,对比了该算法与灰度共生矩阵、传统LBP算子在钢丝绳图像分割中的效果.结果表明,该算法可以有效地对钢丝绳图像进行纹理分割,并能取得良好的边界定位效果,性能优于另外两种算法.     

架构于双树轮廓波及GGD模型的纹理图像检索

提出一种基于双树轮廓波变换的纹理图像检索方法.双树轮廓波由塔型双树方向滤波器组构建,它保持了轮廓波灵活的方向选择性,同时克服了传统轮廓波不具有移不变性的缺点.根据双树轮廓波系数的统计特性,本文利用广义高斯分布对各子带进行建模,采用矩估计法提取模型参数,并用KL距离度量图像之间的相似度,实现纹理图像检索.为评价检索性能,从Brodatz图库创建了包含800幅纹理图像的数据库.实验结果表明,本文算法的平均检索率比基于小波和轮廓波的方法分别提高了10.46%和6.94%,而且保持了较高的计算效率.     

基于分块主色和形状特征的彩色图像检索

提出一种新的基于分块主色和形状特征的图像检索算法。图像首先被划分为不同分块,并提取分块主色,然后采用主色直方图作为图像的颜色特征。同时,提出采用平坦度和凹凸度来描述图像的形状特征,在分析平坦度和凹凸度统计特性的基础上,提出了新的量化的方法,并采用量化后的特征直方图作为图像的形状特征。试验结果表明,本文方法在图像的相似性检索时是很有效的,并具有较高的检索效率。     

红外图像实时增强的新算法

针对红外图像的特点,提出了一种红外图像实时增强的新算法。该算法通过分析图像的直方图,得到图像中目标像素数峰值的估计值,并作为平台直方图均衡化的阈值。用该阈值对直方图进行修正,然后通过修正后的直方图进行直方图均衡化。在FPGA内通过采用并行处理结构及流水线技术实现了该算法,并且每秒可处理25帧128×128×8bits的红外图像。理论分析和实验结果均表明,本算法克服了采用一般直方图均衡化增强红外图像的缺点?对背景和噪声增强过度,抑制了目标的增强。该算法对红外图像增强后,图像对比度是直方图均衡化增强后图像对比度的1.8倍。     

CBIR中基于纹理特征的检索概述

本文简要叙述了图像检索的发展和目前研究的热点。基于纹理的图像检索是进行图像检索的主要方法之一，本文主要概述的提取纹理特征的方法。在多种提取纹理特征的方法中，Gabor小波变换和纹理谱的方法更加符合人类的视觉特征，本文对这两种方法进行了理论上的探讨。     

基于SLIC超像素分割的图分割算法

图像分割是对图像进行分析和理解的关键步骤,是计算机视觉的基本技术之一.计算复杂度是评判一个图像分割算法好坏的重要标准,因此降低算法的计算复杂度是当前图像分割领域的主要任务之一.本文提出了一种基于SLIC超像素分割的图像分割方法.该方法利用SLIC算法生成超像素,通过构造相应的相似性矩阵,有效降低了Ncut分割算法的计算复杂度,大幅度缩短了Ncut算法的运行时间.由于SLIC超像素分割算法的准确性与高效性,在进行三类自然图像分割实验时,本文提出的方法无论在分割效果,还是在运行时间上,都要明显优于Ncut分割方法及它的改良算法.     

非负矩阵分解耦合视觉词典的图像检索算法

目的解决当前图像检索技术中,图像特征稀疏编码收敛速度慢,以及局部特征空间信息不足易导致检索误差较大等问题,提出一种基于l0稀疏约束非负矩阵分解耦合视觉词典优化的图像检索算法。方法首先,在非负矩阵分解(Non-negative Matrix Factorization,NMF)的基础上,对系数矩阵设置l0个约束来限制其稀疏性,从而定义一种l0稀疏约束的NMF方法。再通过一种自适应序列词典初始化方案,从训练样本获得词典的初始估计。然后,利用l0稀疏约束的NMF来增强视觉词典,对图像局部描述符进行稀疏编码,并利用最大池化操作来生成聚合特征向量,从而保留局部描述符的关键属性。最后根据得到的特征向量,引入Minkowski距离来衡量查询图像与数据库的相似性,输出检索图像。结果实验结果表明,与当前图像检索方案相比,所提算法具有更高的查准-查全率和收敛速度。结论所提算法返回的图像与查询图像相似度高,在包装商标检索等领域具有一定的参考价值。     

基于TV-泊松奇异积分联合先验模型的图像重构

目的针对当前图像重构算法容易产生过渡平滑图像纹理区域,使复原图像丢失大量纹理,降低重构图像视觉质量等缺陷,提出TV-泊松奇异积分联合先验模型耦合贝叶斯推理的图像重构算法。方法引入配分函数,结合TV函数,构造TV图像先验。定义泊松奇异积分先验,并将其嵌入到TV先验中,设计一种联合先验模型,控制图像纹理平滑度。基于高阶统计量技术,完善图像退化模型,并耦合先验模型,生成重构图像的最大后验估计MAP。引入优化最小原则,求解MAP,完成贝叶斯推理,获取重构图像。对文中算法复原图像纹理的关键参数进行优化,并研究分析该算法的用户响应。结果与当前图像重构算法相比,文中算法的复原视觉质量更高,能够较好地平衡噪声与纹理。在图像退化程度较大时,文中算法具有良好的用户响应。结论文中算法能够较好地同步保持图像边缘与纹理。     

旋转不变纹理特征用于两级图像检索

针对图像中常见的旋转问题提出一种旋转不变纹理特征进行两级图像检索的方法。粗检中,通过坐标变换把图像的旋转转换为行移,并提取近似行移不变的小波特征,结合粗比较算法对整个图像库进行粗检。然后对通过粗检的图像进行 Gabor 变换,提取旋转不变精检索特征,并使用Canberra 距离进行相似性度量。通过对旋转图像库的测试表明,该方法不仅加快了运算速度,且当参数选择适当时,在相同特征条件下,检索率比直接使用精检索方法检索时还提高了 1.625%。     

Contrast enhancement via texture region based histogram equalization

Abstract

This paper presents two novel contrast enhancement approaches using texture regions-based histogram equalization (HE). In HE-based contrast enhancement methods, the enhanced image often contains undesirable artefacts because an excessive number of pixels in the non-textured areas heavily bias the histogram. The novel idea presented in this paper is to suppress the impact of pixels in non-textured areas and to exploit texture features for the computation of histogram in the process of HE. The first algorithm named as Dominant Orientation-based Texture Histogram Equalization (DOTHE), constructs the histogram of the image using only those image patches having dominant orientation. DOTHE categories image patches into smooth, dominant or non-dominant orientation patches by using the image variance and singular value decomposition algorithm and utilizes only dominant orientation patches in the process of HE. The second method termed as Edge-based Texture Histogram Equalization, calculates significant edges in the image and constructs the histogram using the grey levels present in the neighbourhood of edges. The cumulative density function of the histogram formed from texture features is mapped on the entire dynamic range of the input image to produce the contrast-enhanced image. Subjective as well as objective performance assessment of proposed methods is conducted and compared with other existing HE methods. The performance assessment in terms of visual quality, contrast improvement index, entropy and measure of enhancement reveals that the proposed methods outperform the existing HE methods.     

基于包装外观特征图像内容检索方法研究

针对包装外观特征图像信息在图像数据特征的表述、图像内容的检索方法上进行了阐述,并对图像中的颜色特征、纹理特征、轮廓特征进行了表述分析,以便于图像特征的提取和图像内容的匹配,从而实现图像内容的检索,为图像数据库的储存、检索、处理提供相应的处理技术。     

一种基于马尔可夫随机场的运动目标检测算法

本文提出了一种基于马尔可夫随机场的运动目标检测算法.针对传统时间分割使用主观固定阁值的缺点,使用马尔可夫随机场模型对差分图像建模,并提出了一种新的模型阶次选择算法,以及一种可以加速收敛过程的随机场迭代算法.采用期望最大算法获取高斯分布参数并检测运动变化区域,利用形态学运算修正时间分割模板;空间分割部分提出了基于人眼视觉特征的改进分水岭算法,有效地解决了过分割问题;最后对时、空间分割结果进行信息融合处理,从而得到完整的运动目标.仿真实验结果证明了本文算法可以有效地分割视频运动目标.     

Severity detection and infection level identification of tuberculosis using deep learning

Tuberculosis (TB) is a highly infectious disease and is one of the major health problems all over the world. The accurate detection of TB is a major challenge faced by most of the existing methods. This work addresses these issues and developed an effective mechanism for detecting TB using deep learning. Here, the color space transformation is applied for transforming the red green and blue image to LUV space, where L stands for luminance, U and V represent chromaticity values of color images. Then, adaptive thresholding is carried out for image segmentation and various features, like coverage, density, color histogram, area, length, and texture features, are extracted to enable effective classification. After the feature extraction, the size of the features is reduced using principal component analysis. The extracted features are subjected to fractional crow search-based deep convolutional neural network (FC-SVNN) for the classification. Then, the image level features, like bacilli count, bacilli area, scattering coefficients and skeleton features are considered to perform severity detection using proposed adaptive fractional crow (AFC)-deep CNN. Finally, the inflection level is determined using entropy, density and detection percentage. The proposed AFC-Deep CNN algorithm is designed by modifying FC algorithm using self-adaptive concept. The proposed AFC-Deep CNN shows better performance with maximum accuracy value as 0.935.     

Embedding Image Through Generated Intermediate Medium Using Deep Convolutional Generative Adversarial Network

Deep neural network has proven to be very effective in computer vision fields. Deep convolutional network can learn the most suitable features of certain images without specific measure functions and outperform lots of traditional image processing methods. Generative adversarial network (GAN) is becoming one of the highlights among these deep neural networks. GAN is capable of generating realistic images which are imperceptible to the human vision system so that the generated images can be directly used as intermediate medium for many tasks. One promising application of using GAN generated images would be image concealing which requires the embedded image looks like not being tampered to human vision system and also undetectable to most analyzers. Texture synthesizing has drawn lots of attention in computer vision field and is used for image concealing in steganography and watermark. The traditional methods which use synthesized textures for information hiding mainly select features and mathematic functions by human metrics and usually have a low embedding rate. This paper takes advantage of the generative network and proposes an approach for synthesizing complex texture-like image of arbitrary size using a modified deep convolutional generative adversarial network (DCGAN), and then demonstrates the feasibility of embedding another image inside the generated texture while the difference between the two images is nearly invisible to the human eyes.