Real-time 3D Reconstruction and Rendering for Minimally Invasive Surgery with Multi Cameras Array

Real-time 3D Reconstruction and Rendering for Minimally Invasive Surgery with Multi Cameras Array
Author: Jianwei Ke
Publisher:
Total Pages: 0
Release: 2024
Genre:
ISBN:
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Advancements in digital camera technologies have led to significantly smaller camera sensors without compromising imaging quality. This trend opens avenues for replacing single-camera systems with multi-camera arrays, offering benefits such as an expanded field-of-view and 3D information. However, camera arrays require additional processing to interpret the collected image data. This report addresses two significant algorithmic challenges in developing a camera array. The first challenge involves virtual view generation, which is the task of estimating the image for a virtual camera using image data from multiview cameras. Ideally, if the geometry of the underlying scene is known, the virtual view can be generated by projecting the 3D geometry to the virtual camera. However, finding the 3D geometry of a scene from multiview cameras is an active research topic in Computer Vision. Considering the real-time processing requirement (

Interactive Focus of Light Fields for 3D Displays

Interactive Focus of Light Fields for 3D Displays
Author: Karen A. Lin
Publisher:
Total Pages: 72
Release: 2007
Genre:
ISBN:
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We desire to render scenes onto 3D displays for realtime applications based on image data, targeting media such as streaming multi-view video. The conventional method for rendering would be to first perform 3D reconstruction of the image data, then render the 3D geometric and texture data. However, this approach would be too slow and would lack robustness for complex scenes. Instead, we take an image based approach by using appropriate filtering. Our approach interpolates limited light field data of a 3D scene to simulate depth of field, so that we are able to render new stereo pair views from camera array data in realtime. This allows users to roam in front of a 3D display and still experience seamless natural viewing. We produce these images by convolving 2D image data with an elliptical Gaussian. By shearing the line-like Gaussian to minimize variance over an area-of-interest, the application determines the depth of a user designated pixel. This lets users change focus in realtime, so that their vision does not feel inhibited by the shallower focal depth. Instead, they are able to better focus on the details of their current interest. Our method can be combined with eye trackers and video data for minimally invasive surgery, video conferencing, or any other remote controlled interactive visual applications for enhanced realistic viewing experience.

A Framework for Realtime 3-D Reconstruction by Space Carving Using Graphics Hardware

A Framework for Realtime 3-D Reconstruction by Space Carving Using Graphics Hardware
Author: Christian Nitschke
Publisher: diplom.de
Total Pages: 153
Release: 2007-03-05
Genre: Technology & Engineering
ISBN: 3956362012
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Inhaltsangabe:Introduction: Reconstruction of real-world scenes from a set of multiple images is a topic in Computer Vision and 3D Computer Graphics with many interesting applications. There is a relation to Augmented and Mixed Reality (AR/MR), Computer-Supported Collaborative Work (CSCW), Computer-Aided industrial/architectural Design (CAD), modeling of the real-world (e.g. computer games, scenes/effects in movies), entertainment (e.g. 3D TV/Video) and recognition/analyzing of real-world characteristics by computer systems and robots. There exists a powerful algorithm theory for shape reconstruction from arbitrary viewpoints, called shape from photo-consistency. However, it is computationally expensive and hence can not be used with applications in the field of 3D video or CSCW as well as interactive 3D model creation. Attempts have been made to achieve real-time framerates using PC cluster systems. While these provide enough performance they are also expensive and less flexible. Approaches that use GPU hardware-acceleration on single workstations achieve interactive framerates for novel-view synthesis, but do not provide an explicit volumetric representation of the whole scene. The proposed approach shows the efforts in developing a GPU hardware-accelerated framework for obtaining the volumetric photo hull of a dynamic 3D scene as seen from multiple calibrated cameras. High performance is achieved by employing a shape from silhouette technique in advance to obtain a tight initial volume for shape from photo-consistency. Also several speed-up techniques are presented to increase efficiency. Since the entire processing is done on a single PC, the framework can be applied to mobile setups, enabling a wide range of further applications. The approach is explained using programmable vertex and fragment processors and compared to highly optimized CPU implementations. It is shown that the new approach can outperform the latter by more than one magnitude. The thesis is organized as follows: Chapter 1 contains an introduction, giving an overview with classification of related techniques, statement of the main problem, novelty of the proposed approach and its fields of application. Chapter 2 surveys related work in the area of dynamic scene reconstruction by shape from silhouette and shape from photo-consistency. The focus lies on high performance reconstruction and hardware-acceleration. Chapter 3 introduces the theoretical basis for the proposed [...]

Visual SLAM And Surface Reconstruction For Abdominal Minimally Invasive Surgery

Visual SLAM And Surface Reconstruction For Abdominal Minimally Invasive Surgery
Author: Bingxiong Lin
Publisher:
Total Pages:
Release: 2015
Genre: Computer science
ISBN:
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Depth information of tissue surfaces and laparoscope poses are crucial for accurate surgical guidance and navigation in Computer Assisted Surgeries (CAS). Intra-operative Three Dimensional (3D) reconstruction and laparoscope localization are therefore two fundamental tasks in CAS. This dissertation focuses on the abdominal Minimally Invasive Surgeries (MIS) and presents laparoscopic-video-based methods for these two tasks. Different kinds of methods have been presented to recover 3D surface structures of surgical scenes in MIS. Those methods are mainly based on laser, structured light, time-of-flight cameras, and video cameras. Among them, laparoscopic-video-based surface reconstruction techniques have many significant advantages. Specifically, they are non-invasive, provide intra-operative information, and do not introduce extra-hardware to the current surgical platform. On the other side, laparoscopic-video-based 3D reconstruction and laparoscope localization are challenging tasks due to the specialties of the abdominal imaging environment. The well-known difficulties include: low texture, homogeneous areas, tissue deformations, and so on. The goal of this dissertation is to design novel 3D reconstruction and laparoscope localization methods and overcome those challenges from the abdominal imaging environment. Two novel methods are proposed to achieve accurate 3D reconstruction for MIS. The first method is based on the detection of distinctive image features, which is difficult in MIS images due to the low-texture and homogeneous tissue surfaces. To overcome this problem, this dissertation first introduces new types of image features for MIS images based on blood vessels on tissue surfaces and designs novel methods to efficiently detect them. After vessel features have been detected, novel methods are presented to match them in stereo images and 3D vessels can be recovered for each frame.

3D Reconstruction

3D Reconstruction
Author: Christian Nitschke
Publisher: VDM Publishing
Total Pages: 135
Release: 2007
Genre: Computers
ISBN: 9783836410625
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Our environment is more and more shaped by the influence of digital media which itself evolves at tremendous pace. A small example: 15 years ago, offthe- shelf computers were only able to cope with flat 2D graphics. Improvements in system design made it possible to process 3D scenes, leading to a powerful contribution to our everyday life. However, such scenes need to be created by experienced artists employing difficult and expensive tools. The increasing demand for realism makes things not easier. At the same time, the rapid improvement of commodity hardware enables the development of low cost systems for 3D photography. How can systems for volumetric scene reconstruction be efficiently designed? How may high quality be combined with real-time processing? And how is it possible to create a lightweight architecture using a single computer? After presenting an introductory overview and sketching a novel approach to scene reconstruction, the author Christian Nitschke gives a survey of related work in high-performance reconstruction by shape from silhouette and shape from photo-consistency. To convey a profound understanding to the reader he explains the fundamentals of scene and camera geometry, image formation, light and color as well as 3D reconstruction from multiple views. The novel approach is then introduced in two steps by mapping a basic algorithm to an advanced algorithm using graphics hardware acceleration. Performance and quality issues are analyzed and discussed in detail. The book aims at software and system engineers, scientists and researchers, technical directors as well as the interested public.

Real Time 3D Reconstruction of Non-structured Domestic Environment for Obstacle Avoidance Using Multiple RGB-D Cameras

Real Time 3D Reconstruction of Non-structured Domestic Environment for Obstacle Avoidance Using Multiple RGB-D Cameras
Author: Jordi Magdaleno Maltas
Publisher:
Total Pages:
Release: 2015
Genre:
ISBN:
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This thesis presents how to obtain a real-time 3D reconstruction of a non-structured scene using multiple RGB-D cameras with the aim to use it for robot planning. Several techniques have been developed, starting from raycasting. In order to obtain better speeds some point filtering procedures have been used. Finally, a temporal filtering technique is used to replace the raycasting approach, and to provide a better reconstruction, a sparse points filter is implemented.

3D Reconstruction from Stereo and Photometric Cues in Minimally Invasive Surgery

3D Reconstruction from Stereo and Photometric Cues in Minimally Invasive Surgery
Author: Marco Visentini Scarzanella
Publisher:
Total Pages:
Release: 2012
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ISBN:
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During the last decade, an increasing number of advanced platforms for robotic assisted Minimally Invasive Surgery (MIS) have been translated from research concepts to practical systems used in routine clinical settings. Such systems have defined their own niche in the market place and are gaining increasing acceptance by the surgical community. More importantly, they improve surgeons' dexterity and intra-operative visualisation together with the benefits of improved procedural time, safety, consistency and patient outcome. Some of the new technical features integrated within current robotic systems include higher degrees of freedom for more agile manoeuvring, tremor filtering and haptic feedback. Where the next frontier lies in terms of novel means of surgical assistance is in navigation systems that would enable intra-operative surgical guidance, imposing dynamic active constraints and high fidelity augmented reality environments. At the foundation of all navigation systems lies an accurate 3D reconstruction algorithm. To overcome the current limitations of feature-based matching and reconstruction systems, this thesis investigates a method to integrate depth information from conventional stereo 3D reconstruction with photometric cues from Shape-from-Shading techniques. This is further enhanced with a gaze-contingent framework suitable for intra-operative nav- igation during MIS. The resulting system is suitable for applications with existing MIS platforms without the need of additional hardware, ensuring increased accuracy in areas without salient anatomical landmarks or artificially introduced fiducials. Furthermore, a multi-scale feature detector is proposed for intra-operative stereo telestration required for telementoring and remote collaboration of robotic assisted MIS. An improved formulation of the current state-of-the- art in Shape-from-Shading is integrated with intra-operative scenes for accurate metric depth recovery. The potential clinical application of the technique is demonstrated for autonomous navigation of wireless capsule endoscopes. Future research directions and preliminary results of integrating photometric stereo constraints for reliable reconstruction of featureless, non- Lambertian deforming tissue surfaces are provided and all methods proposed have been validated with either in vivo or phantom experiments to justify their potential clinical values in MIS.