Methodologies to represent and promote the geoheritage using unmanned aerial vehicles, multimedia technologies, and augmented reality

Promoting geoheritage using the Internet materializes mainly through the use of maps, posters, informational murals, or websites. This information is usually detailed and visually appealing. However, in most cases, there is little interactivity and a limited or complete lack of contextualization within the geographical space. The main objective of this work was to integrate information collected with unmanned aerial vehicles, georeferenced information processed in geographical information systems, photogram- metry techniques, and multimedia technologies to promote a better computer visualization of geoheritage. A working website was built based on panoramic photography, three-dimensional representation of the terrain, and multimedia information, in order to provide a pleasant way of promoting and interacting with field geology by using the Internet. The navigation through the information is based on 360° spherical panoramic images that are fully oriented and georeferenced. Their movement can be perfectly synchronized with the viewing of the landscape by using motion sensors found on portable devices (tablets or smartphones) such as GPS, accelerometers, gyroscopes, or compasses. These images can include the access to multimedia elements such as websites, videos, images, sounds, interpretation models, text, or interactive 3D terrain models, working as an excellent support base for the provision of an augmented reality experience. If used in the field, this technical implementation can act as an interactive guide for the interpretation of the landscape. This type of content can be accessed online from locations with a network signal or can be obtained in advance for offline use.This work received financial support from Capes - Higher Education Personnel Improvement Coordination for the granted in Brazil between 2013 and 2014 and abroad in 2015. This work was co-funded by the European Union through the European Regional Development Fund, based on COMPETE 2020 (Programa Operacional da Competitividade e Internacionalização), project ICT (UID/GEO/04683/2013) with reference POCI-01-0145-FEDER-007690 and national funds provided by Foundation of Science and Technology (FCT)

Data Fusion of Objects Using Techniques Such as Laser Scanning, Structured Light and Photogrammetry for Cultural Heritage Applications

In this paper we present a semi-automatic 2D-3D local registration pipeline capable of coloring 3D models obtained from 3D scanners by using uncalibrated images. The proposed pipeline exploits the Structure from Motion (SfM) technique in order to reconstruct a sparse representation of the 3D object and obtain the camera parameters from image feature matches. We then coarsely register the reconstructed 3D model to the scanned one through the Scale Iterative Closest Point (SICP) algorithm. SICP provides the global scale, rotation and translation parameters, using minimal manual user intervention. In the final processing stage, a local registration refinement algorithm optimizes the color projection of the aligned photos on the 3D object removing the blurring/ghosting artefacts introduced due to small inaccuracies during the registration. The proposed pipeline is capable of handling real world cases with a range of characteristics from objects with low level geometric features to complex ones

Recent Progress in Image Deblurring

This paper comprehensively reviews the recent development of image deblurring, including non-blind/blind, spatially invariant/variant deblurring techniques. Indeed, these techniques share the same objective of inferring a latent sharp image from one or several corresponding blurry images, while the blind deblurring techniques are also required to derive an accurate blur kernel. Considering the critical role of image restoration in modern imaging systems to provide high-quality images under complex environments such as motion, undesirable lighting conditions, and imperfect system components, image deblurring has attracted growing attention in recent years. From the viewpoint of how to handle the ill-posedness which is a crucial issue in deblurring tasks, existing methods can be grouped into five categories: Bayesian inference framework, variational methods, sparse representation-based methods, homography-based modeling, and region-based methods. In spite of achieving a certain level of development, image deblurring, especially the blind case, is limited in its success by complex application conditions which make the blur kernel hard to obtain and be spatially variant. We provide a holistic understanding and deep insight into image deblurring in this review. An analysis of the empirical evidence for representative methods, practical issues, as well as a discussion of promising future directions are also presented.Comment: 53 pages, 17 figure

Uses of uncalibrated images to enrich 3D models information

The decrease in costs of semi-professional digital cameras has led to the possibility for everyone to acquire a very detailed description of a scene in a very short time. Unfortunately, the interpretation of the images is usually quite hard, due to the amount of data and the lack of robust and generic image analysis methods. Nevertheless, if a geometric description of the depicted scene is available, it gets much easier to extract information from 2D data. This information can be used to enrich the quality of the 3D data in several ways. In this thesis, several uses of sets of unregistered images for the enrichment of 3D models are shown. In particular, two possible fields of application are presented: the color acquisition, projection and visualization and the geometry modification. Regarding color management, several practical and cheap solutions to overcome the main issues in this field are presented. Moreover, some real applications, mainly related to Cultural Heritage, show that provided methods are robust and effective. In the context of geometry modification, two approaches are presented to modify already existing 3D models. In the first one, information extracted from images is used to deform a dummy model to obtain accurate 3D head models, used for simulation in the context of three-dimensional audio rendering. The second approach presents a method to fill holes in 3D models, with the use of registered images depicting a pattern projected on the real object. Finally, some useful indications about the possible future work in all the presented fields are given, in order to delineate the developments of this promising direction of research