A total color difference measure for segmentation in color images

A single-value total color difference (TCD) measurement for scene segmentation is proposed and evaluated experimentally. Both chrominance and luminance difference criteria are considered. The luminance component is defined by a unit in luminance change expressed in terms of MacAdam's Just Noticeable Difference, JND. The chromaticity component is derived directly from JND. Experiments using both pixel and region analysis show that the proposed TCD can effectively indicate object boundaries over a wide range of luminance changes. The results have been evaluated both subjectively and quantitatively. For comparison purposes, results have been obtained in several color spaces.     

基于机器视觉的色差检测算法

针对金属印刷质量中的色差检测问题,采用机器视觉的技术对色差检测算法进行了研究。通过在金属印刷品的留白区域印刷色标,使用工业CCD相机采集金属印刷产品上的色标区域,使用数字图像处理技术提取色标。使用了基于HSV颜色空间的色差检测算法和基于CIELAB颜色空间的色差检测算法,分析了两种颜色空间下色差检测的实验结果,采用两种颜色空间检测算法相结合的方法,实现对色差合理有效的快速检测,同时能保证检测结果的准确性。     

Image indexing and retrieval based on color histograms

While general object recognition is difficult, it is relatively easy to capture various primitive properties such as color distributions, prominent regions and their topological features from an image and use them to narrow down the search space when attempts to retrieving images by contents from an image database are made.In this paper, we present an image database in which images are indexed and retrieved based on color histograms. We first address the problems inherent in color histograms created by the conventional method, and then propose a new method to create histograms which are compact in size and insensitive to minor illumination variations such as highlight, shape, and etc. A powerful indexing scheme where each histogram of an image is encoded into a numerical key, and stored in a two-layered tree structure is introduced. This approach turns the problem of histogram matching, which is computation intensive, into index key search, so as to realize quick data access in a large scale image database. Two types of user interfaces, Query by user provided sample images, and Query by combination of the system provided templates, are provided to meet various user requests. Various experimental evaluations exhibit the effectiveness of the image database system.     

提升小波在木材颜色特征提取上的应用

在总结以往研究的基础上,结合图像分块理论,提出一种新的木材颜色特征提取方法.该方法基于提升小波变换提取木材表面的颜色信息,最终形成12个特征参数.为了验证特征提取的有效性,采用了径向基函数神经网络、概率神经网络和支持向量机三种分类器,最终实验仿真的分类效果很好,验证了这种新的颜色特征提取方法的有效性.     

基于视觉颜色感知——光学相似的图像去雾方法

针对雾霾环境影响致使户外获取的图像质量严重下降问题，提出了一种基于视觉颜色感知—光学相似的图像去雾方法。充分利用人眼感知颜色的视觉机理，结合图像的相似性原理，构造了光学相似度函数，建立了新的基于视觉颜色感知—光学相似的图像去雾模型并设计相关算法，进而进行仿真验证。仿真实验结果表明，提出的方法在对有雾图像清晰化处理过程中效果明显，并与现有的图像去雾方法在主观视觉和客观量化方面进行图像去雾效果对比，进一步表明提出的方法在清晰化含雾图像处理中取得了较好的效果。     

高动态范围图像及其色彩迁移

高动态范围图像是一种可以大范围表示场景中亮度的变化,像素值正比于场景实际亮度的图像类型。对高动态范围图像以及普通图像间的色彩迁移进行了研究。先将图像变换到正交的色彩空间,然后根据图像的色彩信息统计值,将参考图像的色彩迁移至目标图像中,使生成的新图像具有参考图像的整体色彩特征。实验表明,色彩迁移效果满意。     

基于YIQ色彩空间的彩色图像盲水印算法*

提出了一种将彩色图像作为数字水印嵌入到彩色宿主图像中的新算法,用于图像版权保护。将彩色水印图像进行一维数字化处理,并将彩色宿主图像由RGB色彩模式转换成YIQ色彩模式,采用整数小波变换将彩色水印嵌入到彩色图像YIQ色彩空间的Y分量中。彩色水印的提取不需要原始水印和原始宿主图像。实验表明：该数字水印算法不仅具有良好的透明性,而且对诸如叠加噪声、JPEG压缩、几何剪切、平滑滤波等攻击具有很强的鲁棒性。     

基于L*a*b*空间颜色信息度量的边缘检测

对L*a*b*空间进行分析,提出了一种基于颜色信息度量的边缘检测算法.通过在L*a*b*空间中构造立方体,根据体积变化定义各像素点的颜色信息度量,作为确定各像素点是否为彩色图像的边缘点的判据.该方法综合利用了彩色图像的明度和色度信息,将向量空间的计算以自然的方式转换成了标量的计算.实验证明,与传统的方法相比较,能快速有效地检测出图像的边缘.     

彩色图像的亮度-色度非线性重组

灰度变换技术直接用于彩色图像的RGB各分量可以提高其对比度,但却会引起彩色失真;而基于Retinex理论的多尺度彩色复原算法（MSRCR）可以改善彩色图像的视觉效果,也不会引起彩色失真,但存在控制参数的取值问题,自适应性不是很好,更大的缺陷在于卷积运算巨大的运算量导致处理时间偏长。提出了一种基于灰度变换的自适应彩色图像增强算法,将原始RGB图像和RGB三分量灰度变换后的图像转换到非线性亮度/色度彩色空间,重组两者的色度分量和亮度分量,从而保持了原始图像的色彩。在继承灰度变换算法优点的基础上,扩展了原始图像的有效灰度范围,提高了整体对比度,增强了细节。此外,算法的计算量极小,不需要设定任何参数,可用于自适应实时彩色图像处理。     

一种彩色图像可恢复半脆弱数字水印算法

提出了一种彩色图像可恢复半脆弱数字水印算法,该算法可准确地实现篡改图像的检测、定位及恢复。算法先将彩色图像从RGB空间转换到YCbCr空间,从各分量提取恢复信号,嵌入色度分量Cb、Cr的小波域中高频子带,然后将Y分量的L+1级小波系数调制成检测水印,嵌入到Y分量的最低频子带。认证时,从Y分量中提取检测水印,初步判断篡改位置,再从Cb、Cr分量中提取恢复信号,恢复篡改区域。仿真实验表明,该算法不仅能对彩色图像进行认证及恢复,并对常规信号处理操作具有较好的脆弱性。     

车载摄像机安装方案探讨

针对基于计算机视觉导航的智能车辆摄像机安装问题,在安装高度、安装区域、安装结构及安装方位等方面进行了全面的分析,提出了一种较优的解决方案,论述了如何解耦3个方位角,仅仅利用3条平行线就能保证侧倾角和方向角为0的方法,并给出了工程上的实现方式,最后通过实验验证了该方法的可行性和正确性。     

Screen‐based color vision test for digital quantification of deutan color defects using a color‐calibrated monitor

Display technologies are used in various industries. However, few studies on color vision testing using self‐luminous displays are reported. In this study, a screen‐based color vision test, termed the digital color vision test (DCVT), is developed on a color‐calibrated monitor. A control bar is adjusted by the observer to build just noticeable chromatic difference ellipses in CIE u′v′ chromaticity diagram, which indicate the capabilities of subjects' color visions. Ten color‐normal observers and 13 deutan observers participated in the psychophysical experiments. The observers also performed the other two typical diagnostic tests (D‐15 and anomaloscope). Results from the experiment using the adjustment psychophysical method for digital quantification of deutan color vision defects are presented. It is found that the diagnosis accuracy of the DCVT is approximately equivalent to those of D‐15 and anomaloscope tests.     

Intelligent Robot Vision Sensors in VLSI

Traditional approaches for solving real-world problems using computer vision have depended heavily on CCD cameras and workstations. As the computation power of workstations doubles every 1.5 years, they are now better able to handle the large amount of data presented by the cameras; yet real-time solutions for physical interaction with the real-world continues to be very hard, and relegated to large and expensive systems. Our approach attempts to solve this problem by using computational sensors and small/inexpensive embedded processors. The computational sensors are custom designed to reduce the amount of data collected, to extract only relevant information and to present this information to the simple processor, microcontrollers (Cs) or DSPs, in a format which reduces post-processing latency. Consequently, the post-processors are required to perform only high level computation on features rather than data. These systems are applied to problems such as target acquisition and tracking for image stabilization and autonomous data driven autonavigation for mobile robots. We present an example of a system that uses a pair of computational sensors and a C to solve a toy autonavigation problem.The computational sensors, however, have wide applications in many problems that require image preprocessing such as edge detection, motion detection, centroid localization and other spatiotemporal processing. This paper also presents a general-purpose computational sensor capable of extracting many visual information components at the focal plane.     

一种快速的模糊C均值聚类彩色图像分割方法

FCM用于彩色图像分割存在聚类数目需要事先确定、计算速度慢的问题,为此,提出一种快速的模糊C均值聚类方法（FFCM）。首先,对原始彩色图像进行基于梯度图的分水岭变换,从而把原始彩色图像数据分成一些具有色彩一致性的子集;然后,利用这些子集的大小和中心点进行模糊聚类。由于FFCM聚类样本数量显著减小,因此可以大幅提高模糊C均值聚类算法的计算速度,进而可以采用聚类有效性指标确定聚类数目。实验表明,这种方法不需要事先确定聚类数目,在聚类有效性能不变的前提下,可以使模糊聚类的速度得到明显提高,实现了彩色图像的快速分割。     

嵌入式彩色图像传感器重构系统的设计与实现

为了获取高品质的彩色图像,实现特殊作业现场的图像采集,提出了一种嵌入式彩色CCD图像传感器重构系统的设计方法.通过对图像边界方向的有效判断来完善图像高频区和低频区边界的质量,同时增加三原色之间的耦合性来提高图像清晰度,并且完成了系统的嵌入式底层实现.测试证明:该系统色彩还原效果良好,重构处理时间为34ms,稳定性好,实...     

结合快速融合与颜色传递的双波段夜视图像染色

总结了近15年来的多传感器图像染色技术研究成果,给出了染色算法的一般模型。在此基础上,将图像融合技术与颜色传递技术结合,设计了基于YCbCr颜色空间的夜视微光与红外图像染色算法。使用互调制快速融合充分提取源图像的空间信息,将得到的融合图像指派给Y分量;借鉴Toet提取图像共同分量的思路,构造Cb、Cr分量;最后应用颜色传递技术,获得了细节丰富、目标背景对比度高,符合场景自然颜色分布的彩色图像。因使用了互调制快速融合方法并直接构造颜色分量,染色过程效率高且参数自适应,可满足实时系统应用需求。     

IVVI: Intelligent vehicle based on visual information

Human errors are the cause of most traffic accidents, with drivers’ inattention and wrong driving decisions being the two main sources. These errors can be reduced, but not completely eliminated. That is why Advanced Driver Assistance Systems (ADAS) can reduce the number, danger and severity of traffic accidents. Several ADAS, which nowadays are being researched for Intelligent vehicles, are based on Artificial Intelligence and Robotics technologies. In this article a research platform for the implementation of systems based on computer vision is presented, and different visual perception modules useful for some ADAS such as Line Keeping System, Adaptive Cruise Control, Pedestrian Protector, or Speed Supervisor, are described.     

改进颜色融合的医学图像彩色化技术

彩色化后的医学图像能清晰体现患者病灶信息有利于医患沟通。提出改进颜色融合的医学图像彩色化方法,首先利用基于KNN的图像前背景区分算法,强化病灶区域的边界信息;然后以此为约束条件,只需提供简单的着色输入;最后将边界能量引入颜色融合方法,得到较好的着色结果。着色图像保持了原图的灰度信息不变,增加了彩色标记图像的颜色和真实感。实验结果表明,该算法具有较高的精确度,可有效的应用于医学图像彩色化处理。     

面向智能交通系统的图像处理

图像处理在智能交通系统（ＩＴＳ）中扮演着极其重要的角色。文章综述了目前ＩＴＳ领域中所广泛采用的图像采集设备、图像处理硬件和图像处理软件,并给出了大量的应用实例。最后,结合目前的研究成果对其今后的发展进行了展望。