Practical 3D Reconstruction of Cultural Heritage Artefacts from Photographs – Potentials and Issues

[EN] A new technology is on the rise that allows the 3D-reconstruction of Cultural Heritage objects from image sequences taken by ordinary digital cameras. We describe the first experiments we made as early adopters in a community-funded research project whose goal is to develop it into a standard CH technology. The paper describes in detail a step-by-step procedure that can be reproduced using free tools by any CH professional. We also give a critical assessment of the workflow and describe several ideas for developing it further into an automatic procedure for 3D reconstruction from images.We gratefully acknowledge the funding from the European Commission for the FP7-IP 3D-COFORM under grant No. 231809. With this support, we are confident to provide solutions for the mentioned problems soon.Fellner, DW.; Havemann, S.; Beckmann, P.; Pan, X. (2011). Practical 3D Reconstruction of Cultural Heritage Artefacts from Photographs – Potentials and Issues. Virtual Archaeology Review. 2(4):95-103. https://doi.org/10.4995/var.2011.4564OJS9510324CROFTS N., DOERR M., GILL T., STEAD S., STIFF M.: Definition of the CIDOC Conceptual Reference Model, version 4.2 ed. CIDOC Documentation Standards Working Group, June 2005. Also ISO/PRF 21127, available from cidoc.ics.forth.gr.LONDON CHARTER INITIATIVE (HUGH DENARD): The london charter, June 2006. www.londoncharter.org.PAN, X., BECKMANN, P., HAVEMANN, S., TZOMPANAKI, K., DOERR, M., FELLNER, D.W., A distributed Object Repository for Cultural Heritage, Proc. VAST 2010 conference, Eurographics Press, 201

Word families, allofams, and the comparative method

Linguists researching the Trans-Himalayan family do not have a self-perception as working outside the mainstream of historical linguistics, but ‘word families’ and ‘allofams’ are important elements in their thinking despite the absence of these terms in the wider discipline. A close examination of the practice of historical linguistics in Indo-European and Trans-Himalayan leads to the conclusion that those phenomena treated as word families admit superior analyses in more traditional terms

LIFE-SHARE Project: Developing a Digitisation Strategy Toolkit

This poster will outline the Digitisation Strategy Toolkit created as part of the LIFE-SHARE project. The toolkit is based on the lifecycle model created by the LIFE project and explores the creation, acquisition, ingest, preservation (bit-stream and content) and access requirements for a digitisation strategy. This covers the policies and infrastructure required in libraries to establish successful practices. The toolkit also provides both internal and external resources to support the service. This poster will illustrate how the toolkit works effectively to support digitisation with examples from three case studies at the Universities of Leeds, Sheffield and York

Fine‐Grained Memory Profiling of GPGPU Kernels

Memory performance is a crucial bottleneck in many GPGPU applications, making optimizations for hardware and software mandatory. While hardware vendors already use highly efficient caching architectures, software engineers usually have to organize their data accordingly in order to efficiently make use of these, requiring deep knowledge of the actual hardware. In this paper we present a novel technique for fine‐grained memory profiling that simulates the whole pipeline of memory flow and finally accumulates profiling values in a way that the user retains information about the potential region in the GPU program by showing these values separately for each allocation. Our memory simulator turns out to outperform state‐of‐the‐art memory models of NVIDIA architectures by a magnitude of 2.4 for the L1 cache and 1.3 for the L2 cache, in terms of accuracy. Additionally, we find our technique of fine grained memory profiling a useful tool for memory optimizations, which we successfully show in case of ray tracing and machine learning applications

Landspotting: Social gaming to collect vast amounts of data for satellite validation

At present there is no single satellite-derived global land cover product that is accurate enough to provide reliable estimates of forest or cropland area to determine, e.g., how much additional land is available to grow biofuels or to tackle problems of food security. The Landspotting Project aims to improve the quality of this land cover information by vastly increasing the amount of in-situ validation data available for calibration and validation of satellite-derived land cover. The Geo-Wiki (Geo-Wiki.org) system currently allows users to compare three satellite derived land cover products and validate them using Google Earth. However, there is presently no incentive for anyone to provide this data so the amount of validation through Geo-Wiki has been limited. However, recent competitions have proven that incentive driven campaigns can rapidly create large amounts of input. The LandSpotting Project is taking a truly innovative approach through the development of the Landspotting game. The game engages users whilst simultaneously collecting a large amount of in-situ land cover information. The development of the game is informed by the current raft of successful social gaming that is available on the internet and as mobile applications, many of which are geo-spatial in nature. Games that are integrated within a social networking site such as Facebook illustrate the power to reach and continually engage a large number of individuals. The number of active Facebook users is estimated to be greater than 400 million, where 100 million are accessing Facebook from mobile devices. The Landspotting Game has similar game mechanics as the famous strategy game "Civilization" (i.e. build, harvest, research, war, diplomacy, etc.). When a player wishes to make a settlement, they must first classify the land cover over the area they wish to settle. As the game is played on the earth surface with Google Maps, we are able to record and store this land cover/land use classification geographically. Every player can play the game for free (i.e. a massive multiplayer online game). Furthermore, it is a social game on Facebook (e.g. invite friends, send friends messages, purchase gifts, help friends, post messages onto the wall, etc). The game is played in a web browser, therefore it runs everywhere (where Flash is supported) without requiring the user to install anything additional. At the same time, the Geo-Wiki system will be modified to use the acquired in-situ validation information to create new outputs: a hybrid land cover map, which takes the best information from each individual product to create a single integrated version; a database of validation points that will be freely available to the land cover user community; and a facility that allows users to create a specific targeted validation area, which will then be provided to the crowdsourcing community for validation. These outputs will turn Geo-Wiki into a valuable system for earth system scientists

Dithered Color Quantization

Image quantization and digital halftoning are fundamental problems in computer graphics, which arise when displaying high-color images on non-truecolor devices. Both steps are generally performed sequentially and, in most cases, independent of each other. Color quantization with a pixel-wise defined distortion measure and the dithering process with its local neighborhood optimize different quality criteria or, frequently, follow a heuristic without reference to any quality measure. In this paper we propose a new method to simultaneously quantize and dither color images. The method is based on a rigorous cost–function approach which optimizes a quality criterion derived from a generic model of human perception. A highly efficient algorithm for optimization based on a multiscale method is developed for the dithered color quantization cost function. The quality criterion and the optimization algorithms are evaluated on a representative set of artificial and real–world images as well as on a collection of icons. A significant image quality improvement is observed compared to standard color reduction approaches

Human-Centric Chronographics:Making Historical Time Memorable

A series of experiments is described, evaluating user recall of visualisations of historical chronology. Such visualisations are widely created but have not hitherto been evaluated. Users were tested on their ability to learn a sequence of historical events presented in a virtual environment (VE) fly-through visualisation, compared with the learning of equivalent material in other formats that are sequential but lack the 3D spatial aspect. Memorability is a particularly important function of visualisation in education. The measures used during evaluation are enumerated and discussed. The majority of the experiments reported compared three conditions, one using a virtual environment visualisation with a significant spatial element, one using a serial on-screen presentation in PowerPoint, and one using serial presentation on paper. Some aspects were trialled with groups having contrasting prior experience of computers, in the UK and Ukraine. Evidence suggests that a more complex environment including animations and sounds or music, intended to engage users and reinforce memorability, were in fact distracting. Findings are reported in relation to the age of the participants, suggesting that children at 11–14 years benefit less from, or are even disadvantaged by, VE visualisations when compared with 7–9 year olds or undergraduates. Finally, results suggest that VE visualisations offering a ‘landscape’ of information are more memorable than those based on a linear model. Keywords: timeline, chronographic