Intensity-Based Image Registration and 3-D Image Denoising

本项目主要关注两个重要的图像分析问题。一个是图像配准，即匹配图像或图像体积以用于结构定位、差异检测和其他目的。它广泛应用于医学成像、遥感、指纹或人脸识别等领域。 第二个主要焦点是保留边缘和主要边缘特征的3-D图像去噪。由于图像获取技术的快速发展，3D图像在磁共振成像（MRI）、功能性MRI（fMRI）和其他应用中变得越来越流行。然而，由于硬件缺陷和其他原因，观察到的3D图像通常包含噪声，这些噪声应事先去除，以便随后的图像分析更加可靠。现有的图像配准方法大致可以分为两类：基于特征的图像配准方法和基于灰度的图像配准方法。由于特征选择通常是一个耗时且具有挑战性的过程，因此基于强度的IR方法在各种应用中变得流行。然而，大多数现有的基于亮度的红外方法需要一个参数化的模型来描述图像匹配变换，这往往是很难在实践中验证。在这个项目中，研究人员和他的同事提出了一个基于强度的IR过程，而不施加任何参数形式的匹配变换。因此，所提出的方法有可能大大改善基于强度的红外技术，大大拓宽其应用。在文献中，大多数现有的图像去噪方法是用于分析2-D图像。它们往往具有一定的能力，以保持平面部分的边缘，但不能很好地保持角部分的边缘。它们对3-D情况的直接扩展通常不能有效地处理3-D图像，因为3-D图像的结构通常比2-D图像的结构复杂得多。本计画提出一种新的三维影像去噪方法，能较好地保留影像的边缘及主要边缘特徴。图像在我们的社会中无处不在，从CT，MRI和其他医学成像技术的医疗诊断到全球环境变化的卫星监测。本项目旨在改进图像配准和三维图像去噪技术，这些技术在各种成像应用中得到了广泛的应用。因此，它将对我们的社会产生更广泛的影响，直接影响到医疗诊断、涉及指纹和面部识别的安全系统、遥感技术等的改进。该项目还旨在通过其教育活动促进科学和工程领域的人力资源开发。例如，研究员提供了一个关于图像分析的高级专题课程，来自各个部门的研究生可以从中接受科学研究的系统培训。几个研究生正在和图像处理的研究员一起做论文研究。研究员及其研究生开发的一些计算机软件包将张贴在项目网页上，供其他研究人员下载和使用。从该项目中获得的主要研究成果将在国家和国际会议上提出，并提交学术期刊发表。

This project focuses on two important image analysis problems. One is on image registration, which is to match up images or image volumes for structure localization, difference detection, and other purposes. It is widely used in medical imaging, remote sensing, finger print or face recognition, and so forth. The second major focus is on 3-D image denoising with edges and major edge features preserved. Because of fast progress in image acquisition techniques, 3-D images become increasingly popular in magnetic resonance imaging (MRI), functional MRI (fMRI), and other applications. However, observed 3-D images often contain noise, due to hardware imperfection and other reasons, which should be removed beforehand so that subsequent image analyses would be more reliable. In the literature, existing image registration (IR) methods can be roughly classified into two categories: feature-based IR methods and intensity-based IR methods. Because feature selection is often a time-consuming and challenging process, intensity-based IR methods have become popular in various applications. However, most existing intensity-based IR methods require a parametric model for describing the image matching transformation, which is often difficult to verify in practice. In this project, the investigator and his colleagues propose an intensity-based IR procedure without imposing any parametric form on the matching transformation. Therefore, the proposed method has the potential to greatly improve the intensity-based IR techniques and greatly broaden their applications. In the literature, most existing image denoising methods are for analyzing 2-D images. They often have certain ability to preserve planar parts of the edges, but cannot preserve angular parts of the edges well. Their direct extensions to 3-D cases generally cannot handle 3-D images efficiently, because the structure of 3-D images is often substantially more complicated than that of 2-D images. This project proposes a novel 3-D image denoising method which can preserve edges and major edge features well. Therefore, it would provide a reliable tool for 3-D image denoising.Images are used everywhere in our society, ranging from medical diagnostics by CT, MRI, and other medical imaging techniques to satellite monitoring of global environmental changes. This project aims to improve image registration and 3-D image denoising techniques, which are used broadly in various imaging applications. Thus, it will have broader impacts on our society through its direct impact on improvement of medical diagnostics, security systems involving fingerprint and face recognition, remote sensing techniques, and so forth. This project also aims to contribute to the development of human resources in science and engineering through its educational activities. For instance, the investigator offers an advanced topics course on image analysis, from which graduate students from various departments can receive systematic training in scientific research. Several graduate students are doing their thesis research with the investigator on image processing. Some computer software packages developed by the investigator and his graduate students would be posted on a project web page for other researchers to download and use. The major research results obtained from this project would be presented in national and international conferences, and be submitted for publication in academic journals.