An IBR method: Panoramic mosaics of slit images with depth

Providing a wider movement range of virtual camera is an unsolved problem for state-of-the-art image-based rendering system. In this paper, we present a new image based rendering technology called panoramic mosaics of slit images with depth that can provide large virtual camera motion region for some scenes. By limiting camera motion to a horizontal plane only, a slit image with united depth value is used as the rendering element. The panoramic mosaics of slit images with depth are easy to capture, and the data size is as small as that of panorama. We present here the capturing, construction as well as rendering process of panoramic slit images mosaic with depth. In addition, we present the join up process of multiple panoramic slit images mosaic with depth. Project(69823003) supported by NSFC     

基于Fourier-Mellin变换的全景图像拼接与曲线匹配

基于Fourier—Mellin变换的图像配准方法,本文对于图像拼接与曲线匹配进行新探讨。该方法在不需要准确控制相机运动,不需要知道相机的焦距等内部参数及检测图像特征,在配准精度要求不是很高的情况下,直接生成的全景图像可以满足很多实际需求;先将图像曲线转化为二值图像,然后应用Fourier—Mellin变换对这些二值图像进行配准,从而达到两条曲线的匹配。     

基于Hough变换的运动模糊方向鉴别方法

曝光的瞬间,由于物体与成像系统产生相对运动造成图像降质而导致图像模糊,这一短暂过程虽可近似地作为匀速直线运动来处理,但是模糊图像中模糊方向未知。若能从模糊图像出发,估计出运动模糊方向,则可通过图像旋转将运动方向旋转到水平轴,这样图像复原问题就可由二维降为一维,大大降低图像复原的难度。为了实现这一目的,提出了一种基于Hough变换的运动模糊方向的估计方法。实验表明,该方法不仅可鉴别出运动模糊方向,而且具有鉴别范围大、鉴别精度高、稳定性好的优点。     

Web-based interactive visualization of 3D video mosaics using X3D standard

INTRODUCTION The visualization of roadside buildings in virtual space using synthetic photorealistic view is one of the common methods for representing the background scene of Car Navigation Systems (CNS) and Internet map services. Since most of these background scenes are implemented by two-dimensional (2D) images, they may give somewhat monotonous impression due to fixed viewpoint position and orientation. For more interactive visualizations that enable arbitrary ad- justment of the …     

基于Levenberg-Marquardt算法的图象镶嵌方法(英文)

基于图象的绘制是计算机视觉和计算机图形学的一个新的很有吸引力的研究领域 ,本文提出了一种基于Leven berg -Marquardt算法的图象镶嵌方法 ,探讨了该算法及其与所处理问题的相关性 ,并对实验结果与结论进行了讨论。     

基于Levenberg-Marquardt算法的图象镶嵌方法

基于图象的绘制是计算机视觉和计算机图形学的一个新的很有吸引力的研究领域，本文提出了一种基于Levenberg-Marquardt算法的图象镶嵌方法，探讨了该算法及其与所处理问题的相关性，并对实验结果与结论进行了讨论。     

数码相机抖动模糊图像的恢复

分析数码相机抖动过程,根据曝光时间的长短,将相机抖动模糊图像分为匀速运动模糊失真图像和双影模糊失真图像2类．匀速运动模糊失真图像的点扩散函数（PSF）为矩形,直接调用MATLAB中点扩散函数的创建函数和维纳滤波图像恢复函数,可实现图像恢复．双影模糊失真图像的点扩散函数较复杂,在一定的先验假设条件下,本文提出斜坡型、正弦型、抛物线型等3种近似模型,分别给出它们的数学表达式,并在MATLAB平台上创建相应的点扩散函数,再调用MATLAB中的维纳滤波图像恢复函数,可实现图像恢复．     

基于第一视角的车辆盲区视野重现

车辆 A 柱盲区和侧方盲区常常会给行车过程带来巨大安全隐患,而现有盲区解决方案大多以第三视角合成显示,因畸变过大及视角过小等原因难以在行车过程中使用。利用摄像头及相关图像处理方法,对车辆盲区部分以第一视角进行重现显示。首先在车辆外部安装一组摄像头,然后利用标定板得到相机内参,之后基于参数计算求得透视变换矩阵,对采集到的图像根据驾驶员视角作透视变换处理,最后利用全景合成算法拼接成一副全景图,借助显示设备将一幅没有盲区的画面实时显示给驾驶员。实验结果表明,该方法能有效消除车辆 A 柱及侧方盲区,适合在行车过程中使用,且处理速度满足实时性要求。     

序列二维医学图象的体绘制法

Volume rendering of 3D data sets composed of sequential 2D medical images has become an important branch in image processing and computer graphics.To help physicians fully understand deep-seated human organs and focuses(e.g.a tumour)as 3D structures.in this paper,we present a modified volume rendering algorithm to render volumetric data,Using this method.the projection images of structures of interest from different viewing directions can be obtained satisfactorily.By rotating the light source and the observer eyepoint,this method avoids rotates the whole volumetric data in main memory and thus reduces computational complexity and rendering time.Experiments on CT images suggest that the proposed method is useful and efficient for rendering 3D data sets.     

基于生成对抗网络的图像盲去运动模糊算法

针对运动图像盲去模糊问题,基于生成对抗网络,提出利用一种端对端方式恢复模糊图像算法。运用生成对抗神经网络方法对运动模糊图像直接复原,跳过估计模糊核过程,增加感知损失作为损失项,使图片内容和全局结构接近。此外,增加结构相似性损失函数作为约束项,进一步提升生成图片与清晰图片的相似性。实验结果表明,新算法可有效去除运动图像模糊。与其它算法相比,所提算法获得的图像更加清晰。     

Gaussian particle filter based pose and motion estimation

Determination of relative three-dimensional (3D) position, orientation, and relative motion between two reference frames is an important problem in robotic guidance, manipulation, and assembly as well as in other fields such as photogrammetry. A solution to pose and motion estimation problem that uses two-dimensional (2D) intensity images from a single camera is de- sirable for real-time applications. The difficulty in performing this measurement is that the process of projecting 3D object features to 2D images is a nonlinear transformation. In this paper, the 3D transformation is modeled as a nonlinear stochastic system with the state estimation providing six degrees-of-freedom motion and position values, using line features in image plane as measuring inputs and dual quaternion to represent both rotation and translation in a unified notation. A filtering method called the Gaussian particle filter (GPF) based on the particle filtering concept is presented for 3D pose and motion estimation of a moving target from monocular image sequences. The method has been implemented with simulated data, and simulation results are provided along with comparisons to the extended Kalman filter (EKF) and the unscented Kalman filter (UKF) to show the relative advantages of the GPF. Simulation results showed that GPF is a superior alternative to EKF and UKF.     

基于Delphi视频采集个人照片的实现

利用微软提供的用于视频捕获的VFWSDK可以实现视频图像捕获。首先介绍了利用Delphi控制视频摄像头进行图像捕获的方法,其次介绍实现对图像内容进行部分选取切割的技巧,最后介绍把图片存放在Access数据库OLE字段中的方法。利用视频对照片的采集、加工、存储为目前管理系统中实时图像的处理提供了一种新方法。     

Depth-aided inpainting for disocclusion restoration of multi-view images using depth-image-based rendering

A new algorithm is proposed for restoring disocclusion regions in depth-image-based rendering （DIBR） warped images. Current solutions include layered depth image （LDI）, pre-filtering methods, and post-processing methods. The LDI is complicated, and pre-filtering of depth images causes noticeable geometrical distortions in cases of large baseline warping. This paper presents a depth-aided inpainting method which inherits merits from Criminisi＇s inpainting algorithm. The proposed method features incorporation of a depth cue into texture estimation. The algorithm efficiently handles depth ambiguity by penalizing larger Lagrange multipliers of flling points closer to the warping position compared with the surrounding existing points. We perform morphological operations on depth images to accelerate the algorithm convergence, and adopt a luma-first strategy to adapt to various color sampling formats. Experiments on test multi-view sequence showed that our method has superiority in depth differentiation and geometrical loyalty in the restoration of warped images. Also, peak signal-to-noise ratio （PSNR） statistics on non-hole regions and whole image comparisons both compare favorably to those obtained by state of the art techniques.     

一种遥感图像高精度自动拼接算法

图像的自动拼接在地理信息系统和全景视频系统中应用广泛,但是传统的自动拼接算法在拼接含有大片相似区域的图片时精度不高,效果不理想.本文在传统算法的基础上,提出一种高精度的自动拼接算法,利用基于特征的算法提取特征点,利用基于像素的算法寻找匹配块,然后根据RANSAC原理精确计算图片的匹配关系.实验证实,该算法在图片包含大量相似区域及重叠部分相对较小的情况下,有比传统算法更高的拼接精度,而计算量并未增加.     

Building virtual models by postprocessing radiology images: A guide for anatomy faculty

Radiology and radiologists are recognized as increasingly valuable resources for the teaching and learning of anatomy. State‐of‐the‐art radiology department workstations with industry‐standard software applications can provide exquisite demonstrations of anatomy, pathology, and more recently, physiology. Similar advances in personal computers and increasingly available software can allow anatomy departments and their students to build their own three‐dimensional virtual models. Appropriate selection of a data‐set, followed by processing and presentation are the key steps in creating virtual models. The construction, presentation, clinical application, and educational potential of postprocessed imaging techniques including multiplanar reformats, minimum intensity projections, segmentation, volume‐rendering, surface‐rendering, fly‐throughs, virtual endoscopy, angiography, and cine‐loops are reviewed using examples created with only a personal computer and freeware software. Although only static images are presented in this article, further material is available online within the electronic version of this article. Through the use of basic and advanced image reconstruction and also paying attention to optimized presentation and integration, anatomy courses can be strengthened with appropriate radiological material. There are several key advantages for the anatomy department, which is equipped with the ability to produce virtual models using radiology images: (1) Opportunities to present anatomy using state‐of‐the‐art technology as an adjunct to current practices, (2) a means to forge an improved relationship with the local radiology department, and (3) the ability to create material locally, which is integrated with the local curriculum avoiding the problem of information overload when using the internet or other commercially available resources. Anat Sci Educ 3:261–266, 2010. © 2010 American Association of Anatomists.     

一种虚拟现实三维空间图像缓存加速新方法

随着虚拟现实技术的更新,渲染硬件也有了新的进展,但是由于现存渲染技能的局限性,较为复杂大型的虚拟场景还是无法以足够高的帧频进行显示.立足于视点替用特效、场景层次细分等概念,提出一种加速三维空间图像缓存的新方法.经实验验证,该方法对于大规模的几何场景具有明显的加速绘制效果.     

基于摄影棚模式的计算机三维产品渲染研究

通过对产品摄影的评价因素和对摄影棚拍摄特点的分析,分别以白色和黑色为渲染背景,建立了基于摄影棚模式的三维产品渲染流程。在虚拟摄影棚左侧、右侧和顶部建立三盏不同的矩形灯光,并结合材质设置和渲染参数设置,就能够渲染出白色背景的精美产品效果图;黑色背景的渲染是以一盏背景灯将产品从黑色背景中烘托出来,并利用模糊倒影来增强产品的立体感;还分析了产品渲染中实景匹配的两种方式,并提出透明材质物体渲染的注意事项。以渲染器Vray为实验平台,渲染结果真实度高。     

基于相位相关法与改进SURF算法的图像拼接方法

为避免相邻图像非重叠区域特征点被检测和提取,加速图像配准,提出一种基于相位相关法与改进SURF算法的快速图像拼接方法。该方法采用相位相关算法确定待拼接图像的重叠区域,限定SURF特征点检测、提取范围,用改进的SURF算法进行特征点匹配|然后根据MSAC算法剔除误配后的特征点匹配对,求取单应性矩阵,实现图像之间的快速配准|最后采用多波段融合算法对配准后的图像进行处理以消除拼接缝。实验结果表明,与传统算法相比,该方法可提高特征点匹配正确率,加速图像配准过程,完成拼接图像间的平滑过渡。     

Non-reference virtual view quality evaluation of MVD

The quality of virtual view based on multi-view video (MVD) plus depth format is often evaluated by PSNR or subjectively judged. However, due to synthesizing arbitrary view images, the virtual view images mostly have no reference images and are only assessed using non-reference. Virtual view images synthesized by depth estimation reference software (DERS) and view synthesis reference software (VSRS) often accompanied with blockiness and other distortions on the edge. In addition, matching level for the depth map and the corresponding texture maps of left and right views also affects the quality of the virtual view. This paper compares the edge similarity of the depth and the corresponding texture maps which generate the intermediate virtual view and combined with the virtual view’s blockiness which causing blur to evaluate the quality of the virtual view. Experiment results show that the proposed method can reflect the quality of the virtual view better.     

全景摄影技术初探——从全景绘画到全息三维立体影像

全景摄影从诞生到发展虽然历时不长,但由于其自身技术与艺术融合的特点,形成了独具特色的发展形式。早期的全景绘画,促使人们对大视角影像产生了极其浓厚的兴趣。伴随着科技的发展,电子产业显示出其强大的推动力,这给摄影注入了新的活力。在摄影器材不断推陈出新的基础上,计算机图像软件让影像制作变得更加神奇。三维影像、全息影像,这些新技术将给全景摄影带来崭新的明天。