The project has just been represented at the Digital Humanities 2014 conference in Lausanne, Switzerland.
The project has just been represented at the Digital Humanities 2014 conference in Lausanne, Switzerland.
If you’d lived in Ancient Egypt, you would probably have strongly believed that death was not the end, and that it was only a transition between this world and the next. Ancient Egyptians believed that after they die, or more precisely after their bodies die, some parts of their soul (termed ‘ka’ and ‘ba’) kept on living in a spiritual realm known as the underworld, or Duat – the realm of the dead.
It was not at all straightforward to get to this underworld. You first had to be mummified so that your body was well preserved and thus suited to move on to the next life. Secondly, you had to pass a crucial test on your judgment day, a procedure known as the ‘weighing of the heart’. If you were a good person and hadn’t sinned, then your heart would be lighter than the feather of truth and justice (Ma’at), and you’d be allowed to continue your journey into the afterlife. Finally, you’d have to know how to overcome all obstacles on your journey, so it was advised to have a copy of the Book of the Dead handy. This book contained magic spells devised to help you to complete your journey successfully.
However, making it to the underworld was not the end of the story. In order to ensure your immortality after death, your family, friends and/or subjects should have remembered to place some food and drinks in your tomb. In addition, even though dead, you were not exempt from work. You were expected to carry out tasks such as ploughing fields and harvesting crops. But if you were well prepared, you made sure that someone else could do the work for you. So while you could enjoy your days watching the sun god Ra on his daily boat ride through the sky, someone else was tasked do the tedious routine chores for you. Therefore, alongside your mummified body, some food, the Book of the Dead, everyday objects, and other paraphernalia needed to smooth your journey into the afterlife, your tomb would include a series of funerary figurines known as shabtis (or ushabtis). These shabtis were usually shaped like a mummy and may have had your name and title inscribed on them. Otherwise, they may have been inscribed with a text from the 6th chapter from the Book of the Dead, including a phrase sending them to action – “to plough the fields, or to fill the channels with water, or to carry sand from the East to the West”.
Tasked mainly for agricultural duties, the shabtis often carried a hoe in their hands, a basket on their backs, or some other tools (depending on their roles). They were usually small, between 10 and 30 cm in size, and would most commonly be made of faience, or otherwise from terracotta, wood, stone, metal or glass. While the practice of using shabtis emerged in the Old Kingdom, they became common starting from the Middle Kingdom onwards and were in use until the end of the Ptolemaic Period. Many of them were made in mass production, and from the 21st Dynasty on, tombs could be found filled with a great number of shabtis. Some tombs had hundreds of shabtis covering the tomb floors. Better be prepared for all that afterlife work!
What is it and how can it be used?
Archaeology was unusually quick to adopt 2D mapping (GIS) technologies at the end of the 1980s and early 1990s, but now 3D approaches to recording everything from small artefacts to whole excavations and large landscapes are fast becoming popular. There are a variety of different methods involved, including both the use of laser scanners (sometimes known as LiDAR, especially when used at the landscape scale) and of photograph-based techniques that fall under the umbrella term ‘photogrammetry’.
MicroPasts is fostering a photogrammetric method known as Structure-from-Motion (SfM) which does away with most of the complicated camera and target set-ups used by more traditional methods. SfM can create 3D colour-realistic models from ordinary digital photographs, often taken in ordinary conditions with ordinary cameras. Most generally, SfM is also a form of ‘computer vision’, the science of allowing computers to ‘see’ the world around them whether through range-finding, still images, video, etc.
3D models are fun to play around with and can be re-used in museum displays, immersive virtual environments or computer games. This is one of the reasons we are making them available under licenses that encourage rather than restrict such unanticipated uses (we would be really interested to hear on the forum of any applications that you can think of). They are also useful for school and university teaching, especially in situations where it is impossible to access the physical objects or archaeological landscapes themselves.
For research purposes, 3D landscape models allow us to place archaeological finds in an accurate topographic setting, and we can also then modify these virtual landscapes better to reflect the way they looked in particular periods of the past. This then allows us to explore more rigorously what factors might, for example, have affected where people from a particular period chose to locate their settlements, or to consider what parts of the archaeological landscape have suffered from erosion or have been covered up by river silts. 3D models of standing buildings (e.g. prehistoric megalithic monuments or Medieval churches, see Susie Green’s blog) not only preserve a 3D snapshot of archaeological structures that unfortunately get damaged and decay through time, but also allow better studies of masonry styles and construction techniques.
3D models of artefacts allow specialists to compare finds in the same virtual space in ways they could never do so physically: for example, you can interact with and compare the details of several different bronze axes via 3D models in ways you could never do physically because those artefacts might each live in a different museum. One key further implication of SfM for artefact-based research is the fact that we can now collect not just one or two models, but hundreds or thousands. This means we can compare the sizes and shapes statistically (e.g. of similar Bronze Age axe types), because the sample of modelled objects is big enough. Although it is early days for such research, the expectation is that computer-based 3D shape analysis will lead to much finer, more informative typologies/taxonomies of objects, a better sense of how these change through time, and in some cases finer dating. You can even apply such statistical comparisons to irregular shapes such as the body-parts of statues (for an example looking at the ears of the Chinese Terracotta Warriors, see here and a related blog post).
How can I create a 3D model?
SfM models are constructed in several distinct steps, involving photo-capture, image-masking, camera alignment, point-cloud construction, meshing and texturing (some of these being obligatory, others optional). There are also ways to use online tools with which anyone can build 3D models via SfM by uploading raw photos they have captured (e.g. photosynth or 123dcatch). However, better results can usually still be achieved offline, and for objects, ‘masking’ out the background of the photo achieves a much better result than simply asking a computer to distinguish crisply between object and background on its own, especially when the object has had to be flipped over at several stages to capture all sides (hence the background has been altered in ways that deceive the computer).
Currently, we have focused on enabling photo-masking tasks on the MicroPasts platform but are currently developing a project where we ask contributors to visit certain kinds of archaeological sites themselves, capture their own photographs and upload them to the site. If you are interested in contributing in this way, you can also have a look at two very good ongoing projects of this kind in Scotland and Wales (heritagetogether or accordproject).
We have written a set of working notes about good practice in creating SfM models (comments and improvements welcome) that will give you a clearer sense of how these methods work (SfM Photographic Strategy, SfM Offline Photo Masking, SfM Model Construction). These working notes provide examples using both commercially-licensed software and open source alternatives wherever possible.
What do we mean by crowd-sourcing?
Crowd-sourcing is a relatively new digital method for collecting information, services or funds from a large group of people, in small chunks, over the internet. This practice emerged less than a decade ago in the commercial sector, where companies had been exploring ways of out-sourcing labour to potentially interested people around the world. It is sometimes also called ‘micro-tasking’ and, as many novelties in the world of technology, it featured in the well-known magazine Wired, where, in 2006, Jeff Howe wrote an article entitled ‘The Rise of Crowd-sourcing’.
In recent years, crowd-sourcing has been increasingly used also by professionals and institutions in the science and cultural heritage sectors as a way of conducting research, curating museum collections and managing heritage resources in collaboration with the public.
In some cases, people are invited to contribute their time and skills to help with projects that have been designed entirely by these institutions. In other cases, members of the public can instead propose ideas for projects they would like to undertake and institutions provide platforms and resources to make them happen.
Some crowd-sourcing platforms, like Zooniverse, host a number of differently themed Citizen Science projects focussing on astronomy, climate issues, nature, biology and the humanities. In other cases, museums, libraries or universities set up individual crowd-sourcing pages linked to their websites, as is the case with the Australian Newspaper Digitisation Programme.
Developing crowd-sourcing platforms where tens or hundreds of thousands of people can work, potentially simultaneously, is a very challenging endeavour. For example, it is important to ensure that data are produced in formats and at levels of quality that allow for meaningful analysis to be undertaken. In this way contributors’ efforts are not wasted and can really bring new knowledge. For this reason, in the MicroPasts transcription applications only information that is entered by at least two contributors in the same way is saved, and, similarly, we have developed a method for maximising the quality of the images masked via photomasking. Another key element is that of communication both within the group of contributors and between contributors and institutions in order to share ideas, confront any problems and propose new initiatives. To this end, MicroPasts uses Facebook, Twitter and a community forum, where we invite comments, suggestions and questions, while providing updates and news about the project.
The technical side…
If you are a developer or just interested in what is ‘behind the scenes’ of the MicroPasts crowd-sourcing website, please do have a look at the code that makes it function.
We have stored it in repositories that are available online on GitHub. Feel free to use and improve the work we have done so far. You might also like to read a step-by-step guide on how to create your own crowd-sourcing applications using the Pybossa framework. We will be happy to answer any questions and hear any observations you might have on MicroPasts software and infrastructure via the forum.
Since late 2013, the MicroPasts team has been preparing the British Museum‘s (BM) Bronze Age Index to be the first offering on our crowd-sourcing platform. This corpus consists of around 30,000 (roughly A4 sized) cards (holding information going back to as early as 1913). The majority of these are double sided and generally have text on the front and a line drawing on the reverse (there are many variants that have been discovered, such as large fold out shield plans.)
Over the last few years, several curators have mooted exercises (Ben Roberts, now at Durham University attempted to turn the transcription into an AHRC funded collaborative Doctoral Award) to turn this amazing resource into a digital archive, but this had not come to fruition until the advent of the MicroPasts project. Internal discussions had been raging on how best to deal with these cards for a number of years, and it was felt that this project could perhaps be the ideal solution and provide museum and public interaction of a new type, which the BM had not explored previously.
To enable this corpus to be digitised is reasonably straight forward and we have employed Dr Jennifer Wexler (@jwexler on Twitter) to manage the scanning process, and she has been doing this since February after her return from field work in Benin.
The equipment needed for this is relatively straight forward, the BM has acquired two high capacity/speed scanners (Canon) which can scan 60 and 100 sheets per minute at 600 dpi and once this initial project is over, they can be reused for turning more archival materials into potential crowd sourcing materials. You can see a picture of Neil’s former office (he’s just moved to a nicer one -we’re not jealous) being used as the scanning centre below in one of his tweets:
— Neil Wilkin (@NWilkinBM) February 10, 2014
The first drawer scanned is known as A9 (this application on the platform), and this was done by the Bronze Age Curator Neil Wilkin (@nwilkinBM on Twitter) over a few weeks whilst dispensing with his other duties. Once Jennifer returned, scanning started in earnest! These high resolution images were then stored in various places to facilitate good data preservation (on an external 4TB hard drive, the Portable Antiquities Scheme server cluster and onto Amazon S3) and they were then stitched together by Daniel Pett (@portableant on Twitter), as composite images using a simple python script and then uploaded to Flickr (for example see this set) for the crowd-sourcing platform to access and then present them as tasks for our audience to assist with. All of these images have been released under the most liberal licence that Flickr permits (we would have ideally liked to make them CC0, but this option does not exist) and so they are served up under a CC-BY licence. The data that will be transcribed, will also be made available for download and reuse by anyone, under a CC0 licence. The embedded tweet below, shows an example of one of the stitched cards:
— Daniel Pett (@portableant) February 21, 2014
The platform that we’re using for serving up the crowd sourcing tasks has been created by Daniel Lombraña González (lead developer – @teleyinex on Twitter) and the Pybossa team, and it is a departure from the usual technology stack that the project team has used previously. Installation of the platform is straightforward and it was deployed on to Portable Antiquities Scheme hardware in around 15 minutes. We then employed Daniel to assist with building the transcription application skeleton (in conjunction with project lead Andy Bevan (not on Twitter!) and Daniel Pett) that would be used for each drawer, whilst we also developed our own look and feel to give MicroPasts some visual identity. If you’re interested, the code is available on GitHub and if you have suggestions from improvements, you could either fork the code or comment on our community forum.
For the last few months, building up to launch, lots of debugging and user testing was conducted to see how the site reacted, whether the tasks we offered were feasible and interesting enough. Chiara Bonacchi (@Chiara_Bonacchi) and Adi Keinan (@Adi_Keinan) worked on the main project site, building our Facebook and Twitter engagement.
Chiara has also developed our evaluation frameworks, which we were integrating into the system and feel are vital to discovering more about people’s engagement with our platforms and how their motivations progress through time, and hopefully the project’s success! This evaluative work hopes to be one of the first following the development of individual users’ interaction on a crowd-sourcing website.
And then we launched and tasks are ongoing:
— Jennifer Wexler (@JWexlerBM) April 16, 2014
This project is very exciting for the BM and especially for our curatorial staff. It could unlock new opportunities and Neil sums up very succinctly, why we are doing this public archaeology project, so we’ll leave it to him:
Opening the treasures of the Bronze Age to the widest public is why I get up, I would love your help: http://t.co/q7eWlIrD9j
— Neil Wilkin (@NWilkinBM) April 16, 2014
Thank you for participating!