ArtServe: a tour d'horizon

Purpose

The site, containing some 450,000 images (nearly 550Gb of storage) is dedicated to visual material useful for teaching and learning Art History and adjacent areas. Artwork (but not publicly visitable architecture) from about the period of World War II onward is excluded for copyright reasons. The great majority of images are conventional stills, but there are ongoing experiments with panoramas and with stereo, and also with hotspotted and zoomable presentations of individual artworks and sites. A brief enthusiasl for VRML (cf. Borobudur) could not be further pursued, partly because of a lack of funding, but largely because VRML does not easily allow the construction of accurate and detailed models.

When visiting monuments and sites, I have usually taken large quantities of images, with plenty of details. All images have been taken without special facilities, and the use of a tripod is abnormal. Indeed, some shots taken indoors are not very sharp; these I have left on the basis of a slightly fuzzy shot being better than none at all. The museums and monuments of several cities (such as Paris, London, Rome Palermo and Lisbon) are quite well covered.

The site began with intended coverage of the Mediterranean Basin - a large enough region for anyone. But given that my home base is Australia, it is understandable that my targets are now wider, ranging from Japan and the mosques of Istanbul to Los Angeles.


History & Growth

http://rubens.anu.edu.au went live on 4th January 1994, and currently (September 2005) receives over sevenmillion "hits" per month with visits from about 13,000 machines each day.


Imaging Technologies

ArtServe reflects changing technologies over the past nine years. The earliest images were frame-grabbed from video, and hence were of video resolution. A few images were scanned, and their size kept small because of the cost of storage as well as the low speed of networks.

Experiments with a Sony PDP digicam and a framegrabber convinced me that on some occasions (e.g. images in Roman churches for parts of the Popolo Project) that it was worth suffering a small image size in order to benefit from the portability and flexibility of a 20x zoom lens and the camera's ability to work down to 3 lumens.

Images on the site also charts the development of digital cameras from the heavy and very expensive 1.2mp of 1995 (the Nikon E1) through the more manageable 2mp and 3mp Olympus models, to the superlight 4mp Pentax Optios used for stereo work, and now the 5mp Nikon Coolpix 5700. Various zooms are possible: there used to be a tradeoff between pixellation and zoomability (as in the excellent Olympus 2100UZ; but manufacturers now offer a wide range of add-on lenses; thus the Coolpix 5700 plus telephoto can get right down to 1:1 tessera level (and better) when photographing for example mosaics in Istanbul.

Better pixellation, cheaper consumer or prosumer cameras and ever-cheapening storage mean that backup strategies continue to change. Until 2003, backup was to AIT tape, and also to 4.2Gb DVDs before the images were mounted on the server. But by mid-2005 hard disk storage had become so cheap that backup is directly to hard disk - over the past two years to a front-opening bay for a removable hard drive on my desktop machine, which backs up over the network (which has also got faster). The latest disks purchased are 300Gb USB external enclosures - and two of them cost what an Amiga 20Mb drive cost in 1990.


Hardware & Software

The first Artserve was a PC running early versions of Linux and the Apache server. Linux and Apache are still used, and migrated to a more powerful PC with a 200Gb RAID array ch was decommissioned in 2002 when external hard disks could be bought so cheaply (see above).

Like Topsy, the site just growed. After an early battle with "informative" filenames, these are now all numerical. The site uses mainly perl scripts for organising databases (from flat files), indexes, and webpages with images.

Out in the field, images are written to a Toshiba Libretto running Windows. ACDSee was used (but now FastStone)for processing the images into directories; Image Assembler and Panorama Factory were used for making panoramas, but now Autostitch, PTAssembler, Enblend and AutoPano. Pixmaker is used to adding hotspots etc to images and panoramas; and 3D Stereo Image Factory for making stereo pairs. In the field, work was backed up on a portable CDROM burner (from HewlettPackard) - but now onto vest-pocket 40Gb hard drives (two of them, to be secure).

Having flirted with VRML, I am now convinced that this tecnology has gone and is going nowhere. Today when I visit architectural sites I try and take overlapping sequences of still images, which are perfectly readable as they stand, and are also the raw material from which stitched panoramas can be created.

The only current snag with large (over 2Mb) panoramas is the time taken for them to load across a network, and the difficulties in getting a Java applet to zoom them either smoothly or at all. Unil the VRML impasse, I am sure that this is a problem which will soon be solved.


Organisation

Earlier sets of images were collected by medium or as surveys (such as prints or Mediterranean architecture). Most material from cities, sites and museums collected in the past few years has been arranged by place, so that the actual directory structure offers a skeleton "database structure" - look at any of the country menus to get the idea. Since I do not have the funds to catalogue each image individually, the classification of the site relies on (a) such a directory structure; (b) hierarchical indexes (perl scripts); and (c) subject-indexes which put together similar materials from the same country (such as antique treasure hoards in England, or ivories in France. An additional aid is the P@noptic search engine, which catalogues the site, and which is accessed from rubens' Home Page.


Michael Greenhalgh
September 2005