基于球体图像的变换方程

视点变换就是在虚拟现实技术中求视点移动后原始图像变换生成的新视图。以前给出的用于全景图像的变换公式都是基于平面或柱面全景图像。论文给出了球体针孔摄像机模型在warping方程中生成新视图的公式,以及具体推导过程。     

基于SIFT算法的嵌入式全景照片系统开发

全景照片也称为全景摄影或虚拟实景,是基于静态图像的虚拟现实技术,即把相机环360°拍摄的一组照片拼接成一个全景图像并进行显示。该文基于SIFT算法和嵌入式系统实现全景摄像技术装置,即通过ARM9平台将步进电机和摄像装置结合实现全景照相装置,之后在服务器通过HGE引擎开发相关系统,引入SIFT衔接算法将拍摄的多张照片进行拼接处理,并构建全景照片的虚拟环境,实现了全景照片的跑马灯展示效果。     

基于立体全景漫游中深度图获取技术的研究

近年来,随着硬件技术的进步和计算机视觉理论的发展,为了增强用户的沉浸感和体验,立体全景技术被广泛应用于生产和生活中。针对多视点立体全景三维重建中深度图的获取问题,提出了一种新的深度图生成方法。首先将前后摄像机拍摄的图像进行配准,然后通过线性变换矩阵得到对应像素点与中心像素的距离,最后利用提出的算法求得深度图。     

柱面全景图像拼合算法研究

IBR技术是近几年来在基于传统几何图形建模方法基础上发展起来的一种新的绘制方法,它用数码相机拍摄到的或计算机生成的照片来绘制新视点处的图像,具有绘制速度与场景的复杂度无关的特点。论文从实际应用的角度,提出并实现了图像拼合的新算法,新算法结合了手动拼合与自动拼合算法的优点,既可用于全景空间图像拼合,亦可用于普通图像的拼合,效率高。     

基于鱼眼图像的全景漫游模型

介绍了如何利用鱼眼镜头所拍摄的图像建立起在固定视点上沿空间任何方向的全景漫游模型的方法 ,它克服了使用普通镜头需要拍摄多幅照片 ,经过拼结 ,缝合处理后才能形成全景图的缺点 ,试验结果证明了该方法的有效性     

基于鱼眼图像的全景漫游模型

介绍了如何利用鱼眼镜头所拍摄的图像建立起在固定视点上沿空间任何方向的全景漫游模型的方法,它克服了使用普通镜头需要拍摄多幅照片,经过拼结,缝合处理后才能形成全景图的缺点,试验结果证明了该方法的有效性.     

用于机器人足球赛的全景视觉设计仿真

该文介绍用于机器人足球中型组比赛的全景视觉系统设计与仿真.该系统由一个普通摄像机和一个全向镜组成,能够拍摄到周围360度的全景图像.该文首先分析了比赛对视觉系统的各项要求,然后对几种常用的全向镜的成像效果进行仿真,得到了它们的全景图像.通过仿真结果比较,发现双曲线镜面具有单视点、变形小、分辨率高、体积小的特点,能够很好地满足比赛的要求.最后给出了摄像机和双曲线镜面的设计参数以及双曲线镜面的仿真图,完成了整个视觉系统的设计.     

基于图像的图形生成系统中的虚拟摄像机模型

一、引言基于图像的计算机图形生成方法是基于模拟的计算模型,该方法有一定的局限性和不足。首先建立场景的几何模型是一件繁琐的工作。其次,在绘制时,计算的复杂性与场景和光源的复杂性相关。最后生成图像真实感不够。而基于图像的计算机图形生成方法是基于全景函数的计算模型,得到完整的全景函数是十分困难的。因此通过对周围场景的拍摄图像等价于对全景函数的稀疏采样。该方法克服了基于几何方法的不足,产生的效果具有图片真实感的效果,其次绘制速度与场景复杂性无关,生成计算机模型方便容易。且不需要最贵的硬件。它是近来的研究热点。基于图像的计算机图像生成方法     

三维全景技术——360°虚拟现实

三维全景技术是目前迅速发展并逐步流行的一个虚拟现实分支,可广泛应用于网络三维业务,也适用于网络虚拟教学领域。传统三维技术及以VRML为代表的网络三维技术都采用计算机生成图像的方式来建立三维模型,而三维全景技术则是利用实景照片建立虚拟环境,按照照片拍摄→数字化→图像拼接→生成场景的模式来完成虚拟现实的创建,更为简单实用。     

虚拟校园三维全景漫游技术研究

本文对全景漫游技术进行了讨论。全景漫游技术中需要解决三个问题：全景图的生成、漫游空间的编辑和浏览器的设计。基于两张圆鱼眼图像生成单张球面全景图,我们开发实现了浙江师范大学校园全景漫游系统。在全景图的生成中,提出了一种基于拼合参数自动寻优的球面全景图生成方法。该方法具有拼合速度快、拼合效果好的特点。     

Image capture pattern optimization for panoramic photography

Panoramic photography requires intensive operations of image stitching. A large quantity of images may lead to a rather expensive image stitching; while a sparse imaging may cause a poor-quality panorama due to the insufficient correlation between adjacent images. So, a good study for the balance between image quantity and image correlation may improve the efficiency and quality of panoramic photography. Therefore, in this work, we are motivated to present a novel approach to estimate the optimal image capture patterns for panoramic photography. We aim at the minimization of the image quantity which still preserves sufficient image correlation. We represent the image correlation as overlap area between the view range that can be separately observed from adjacent images. Moreover, a time-consuming imaging process of panoramic photography will result in a considerable illumination variation of the scene in images. Subsequently, the image stitching will be more challenged. To solve this problem, we design a series of imaging routines for our image capture patterns to preserve the content consistency, ensuring the generalization of our method to various cameras. Experimental results show that the proposed method can obtain the optimal image capture pattern in a very efficient manner. In these patterns, we can obtain a balanced image quantity but still achieve good results of panoramic photography.

     

块拼接纹理合成算法在图像拼接中的应用

小面积图像往往满足不了人们在工作中的需求,很多时候人们需要是大面积的图像,因此就需要一种算法来将相关的小范围拍摄的图像拼接成大图像,即实现全景图拼接。文中从块拼接纹理合成出发,并对块拼接纹理合成算法进行改进,将块拼接的原理应用到图像拼接上,并对像素加入与人视觉有关的权值进行接缝处理。实验结果表明,该方法简单实用,对于基本的由不同方位拍摄的图像都可以通过本算法进行拼接,并通过对接缝处的处理,取得了较好的结果。     

一种街景全景生成的改进算法

当前主流的全景拼接软件在进行投影变换的过程中对街景影像上匹配点对的精度的依赖性较强。为了增强其鲁棒性,采取在投影后的影像上获取匹配点对并将其反投影回街景影像坐标系的策略来减少对初始匹配点对的依赖。此外,针对投影后相邻图像之间的错位导致全景拼接产生缝隙的问题,采用多层B样条插值算法对相邻图像的光流进行插值来消除影像间的错位。实验结果表明,上述的算法策略提高了投影转换的精度,明显改善了全景拼接的效果。     

基于最小路由代价树的大规模显微图像拼接方法

为了对大规模显微图像进行高质量的拼接,首先提出拼接图的概念及获得高质量全景图像的3个原则,然后采用分块-空间聚类算法配准相邻图像,同时评估配准质量,并计算拼接图的边的权值;最后在此基础上,提出了一种基于最小路由代价生成树的图像拼接方法,该方法通过计算拼接图的最小路由代价生成树来确定所有图像的全局位置,并用来生成全景图像。实验结果表明,该方法可获得高质量的全景图像。     

视频图象序列的实时镶嵌技术研究

阐述了一种快速而高效的由视频图象或视频图象序列生成全景的配准方法,为了估计图象配准的校正参数,该方法计算伪运动矢量,这些伪运动矢量是光流在每一选定象素处的粗略估计,使用方法,实现了一个在低价PC上就能实时创建和显示全景图像的软件。     

全景图像生成算法的研究与实现

针对虚拟现实中的柱面全景图生成问题提出了一种简单实用的算法。该算法通过对图像重叠部分的相交特征线段进行提取和匹配来实现相邻图像的拼接。在此基础上编制了全景图生成工具VR-Maker，并取得了良好的实验结果。     

Systems and Experiment Paper: Construction of Panoramic Image Mosaics with Global and Local Alignment

This paper presents a complete system for constructing panoramic image mosaics from sequences of images. Our mosaic representation associates a transformation matrix with each input image, rather than explicitly projecting all of the images onto a common surface (e.g., a cylinder). In particular, to construct a full view panorama, we introduce a rotational mosaic representation that associates a rotation matrix (and optionally a focal length) with each input image. A patch-based alignment algorithm is developed to quickly align two images given motion models. Techniques for estimating and refining camera focal lengths are also presented.In order to reduce accumulated registration errors, we apply global alignment (block adjustment) to the whole sequence of images, which results in an optimally registered image mosaic. To compensate for small amounts of motion parallax introduced by translations of the camera and other unmodeled distortions, we use a local alignment (deghosting) technique which warps each image based on the results of pairwise local image registrations. By combining both global and local alignment, we significantly improve the quality of our image mosaics, thereby enabling the creation of full view panoramic mosaics with hand-held cameras.We also present an inverse texture mapping algorithm for efficiently extracting environment maps from our panoramic image mosaics. By mapping the mosaic onto an arbitrary texture-mapped polyhedron surrounding the origin, we can explore the virtual environment using standard 3D graphics viewers and hardware without requiring special-purpose players.An erratum to this article can be found at     

Rapid omnidirectional vision acquisition using an intelligent linear scanning technique

Many computer vision applications can benefit from omnidirectional vision sensing, rather than depending solely on conventional cameras that have constrained fields of view. For example, mobile robots often require a full 360 view of their environment in order to perform navigational tasks such identifying landmarks, localizing within the environment, and determining free paths in which to move. There has been much research interest in omnidirectional vision in the past decade and many techniques have been developed. These techniques include: (i) catadioptric methods which can provide rapid image acquisition, but lack image resolution; and (ii) mosaicing and linear scanning techniques which have high image resolution but typically have slow image acquisition speed. In this paper, we introduce a novel linear scanning panoramic vision system that can acquire panoramic images quickly with little loss of image resolution. The system makes use of a fast line-scan camera, instead of a slower, conventional area-scan camera. In addition, a unique coarse-to-fine panoramic imaging technique has been developed that is based on smart sensing principles. Using the active vision paradigm, we control the motion of the rotating camera using feedback from the images. This results in high acquisition speeds and proportionally low storage requirements. Experimentation has been carried out, and results are given. Correspondence to: M.J. Barth (e-mail: barth@ee.ucr.edu)     

Panoramic Depth Imaging: Single Standard Camera Approach

In this paper we present a panoramic depth imaging system. The system is mosaic-based which means that we use a single rotating camera and assemble the captured images in a mosaic. Due to a setoff of the camera's optical center from the rotational center of the system we are able to capture the motion parallax effect which enables stereo reconstruction. The camera is rotating on a circular path with a step defined by the angle, equivalent to one pixel column of the captured image. The equation for depth estimation can be easily extracted from the system geometry. To find the corresponding points on a stereo pair of panoramic images the epipolar geometry needs to be determined. It can be shown that the epipolar geometry is very simple if we are doing the reconstruction based on a symmetric pair of stereo panoramic images. We get a symmetric pair of stereo panoramic images when we take symmetric pixel columns on the left and on the right side from the captured image center column. Epipolar lines of the symmetrical pair of panoramic images are image rows. The search space on the epipolar line can be additionaly constrained. The focus of the paper is mainly on the system analysis. Results of the stereo reconstruction procedure and quality evaluation of generated depth images are quite promissing. The system performs well for reconstruction of small indoor spaces. Our finall goal is to develop a system for automatic navigation of a mobile robot in a room.