利用熵和矩进行二值商标图象检索

商标图象的检索在图象库系统管理和应用中得到了越来越多的重视。检索商标图象,形状特征的提取是关键。文章提出了一种新的提取商标图象形状特征的算法。该算法从信息论的角度出发,综合利用图象信息熵及不变矩的特性来描述商标图象的形状特征。该方法算法简单,实验证明具有良好的平移、旋转及尺度不变性,且抗干扰性能良好。     

微焦点X射线成像扫描控制与数据获取系统

文章介绍了微焦点X射线成像扫描控制与数据获取系统的原理、软硬件结构以及实现技术。该系统通过串口通讯协议,实现了实时图像采集的手动扫描控制、自定义扫描轨迹的自动控制,通过图像采集卡采集和存储微焦点X射线图像,为微焦点成像分析处理的研究提供了良好的实验平台。     

精细可伸缩视频编码中的增强层编码方法研究

提出了一种新的子带编码方法来对精细可伸缩视频编码中的增强层进行编码。在这种编码方法中,首先通过重排DCT残差系数形成子带,然后利用同一子带相邻系数的相关性来消除数据冗余。实验结果表明文章提出的增强层编码方法比原来的FGS增强层编码方法具有更高的编码效率。     

自然图像中混叠的概率模型

我们为建立自然图像中混叠的概率模型提供了一个数学框架。假设：(1)图像是由三维物体的二维投影轮廓组成．(2)在简化条件下．我们推导出自然图像的一种解析概率密度函数。已经证明．这种解析表达式可以很好地比配观测到的密度函数(直方图)。我们首先推导图像像素的边缘概率密度函数，然后推广到多维边缘概率密度函数，最后提出了几种改进措施。     

多媒体技术在桥梁工程教学中的应用

本文以桥梁工程专业课教学辅助软件开发为基础，详细介绍了图片、动画、VRML等多媒体手段的基本特点，以及在桥梁工程专业课教学辅助软件中应用的基本方法和优势所在。     

Perceptual grouping of segmented regions in color images

Image segmentation is often the first yet important step of an image understanding system. However, general-purpose image segmentation algorithms that do not rely on specific object models still cannot produce perceptually coherent segmentation of regions at a level comparable to humans. Over-segmentation and under-segmentation have plagued the research community in spite of many significant advances in the field. Therefore, grouping of segmented region plays a significant role in bridging image segmentation and high-level image understanding. In this paper, we focused on non-purposive grouping (NPG), which is built on general expectations of a perceptually desirable segmentation as opposed to any object specific models, such that the grouping algorithm is applicable to any image understanding application. We propose a probabilistic model for the NPG problem by defining the regions as a Markov random field (MRF). A collection of energy functions is used to characterize desired single-region properties and pair-wise region properties. The single-region properties include region area, region convexity, region compactness, and color variances in one region. The pair-wise properties include color mean differences between two regions; edge strength along the shared boundary; color variance of the cross-boundary area; and contour continuity between two regions. The grouping process is implemented by a greedy method using a highest confidence first (HCF) principle. Experiments have been performed on hundreds of color photographic images to show the effectiveness of the grouping algorithm using a set of fixed parameters.     

Weighted thin-plate spline image denoising

This note aims to present new denoising method based on thin-plate splines (TPS). The proposed approach is based on the general TPS denoising Berman [2], however, its unfavorable smoothing of edges and details is suppressed by introduction of a weighting approach applied locally. The performance of the method is shown and compared to the original TPS denoising.     

Discovery of a perceptual distance function for measuring image similarity

For more than a decade, researchers have actively explored the area of image/video analysis and retrieval. Yet one fundamental problem remains largely unsolved: how to measure perceptual similarity between two objects. For this purpose, most researchers employ a Minkowski-type metric. Unfortunately, the Minkowski metric does not reliably find similarities in objects that are obviously alike. Through mining a large set of visual data, our team has discovered a perceptual distance function. We call the discovered function the dynamic partial function (DPF). When we empirically compare DPF to Minkowski-type distance functions in image retrieval and in video shot-transition detection using our image features, DPF performs significantly better. The effectiveness of DPF can be explained by similarity theories in cognitive psychology.     

雷达图像像素矩阵的提取与应用仿真

该文提出采用图像像素矩阵提取的方法，对雷达图像进行特定的处理，该处理方式精确、直接，对原图像影响较小。具有良好的实验效果。同时提出了根据雷达像素矩阵进，行目标识别的思想。     

GIS空间数据管理模式探讨

GIS所涉及的主要是空间数据，所以对于GIS数据库的大量研究都跟空间数据结构和管理模式相关。该文分析了GIs空间数据的特点及其对数据库管理系统的要求，探讨了几种GIS空间数据的管理模式。