Classics and Archaeology Virtual Museum

Images and Movies

Objects Photographed

The content of the Virtual Museum is almost co-extensive with the Classics & Archaeology Collections, but not totally.

Almost all of the Classics & Archaeology Collections have been photographed and incorporated into the Virtual Museum. The important casts and copies in the collections have also been included, for the same reasons as they were acquired in the first place.

Individual items of classical and archaeological interest belonging to other collections at the University, such as the Ernst Mattaei and Geoffrey Kaye Collections, have been included.

Also included were several sets of objects on campus that do not belong to the University:

Omitted from the Virtual Museum Project were:

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Photography

The Multimedia Education Unit provided photographers to the equivalent of two days per week for over a year, at no cost to the project.

It was originally planned that photography would take place in the drawing room next to the archaeology storeroom in the Old Arts building. To this end, objects from various rooms in the John Medley building were packed and taken across to the Old Arts building in the middle of 1996. Refurbishment of the archaeology space, however, made it necessary to pack most of the contents of the storeroom and relocate them to an upstairs storeroom in the University Gallery in the Old Physics Building. This was done at short notice during the project co-ordinator's absence, and the objects were packed mostly without identification in unmarked cartons. There followed several months of unpacking cartons, identifying the objects, accessioning those that had not been accessioned, setting them up on a make-shift photography stand, and advising the photographers about which angles and features were significant. Lack of space meant that only a few cartons could be unpacked at a time. One effect of this was to oblige the photographers to re-arrange their lights and other equipment several times, although every attempt was made to provide them with objects of a similar size and sheen in each session.

More than half the photography was completed when it became necessary to move everything back again to the Old Arts building, where the photographers set up their equipment and the process continued for several months. Objects on display at University House or the Gallery, or in Conservation, were carried across to Old Arts and taken back again as soon as possible. A few delays were caused by attempts to reassemble the scattered sherds of whole pots; parts of some were found in other buildings and, in a couple of cases, in Sydney! After a few months, however, the drawing room was required for other purposes, and the remaining unphotographed objects - including some recent arrivals - were packed and taken across to the Multimedia Education Unit's photographic studio in the Old Pathology building. The coins were all photographed in the studio. Object movie production was, of necessity, restricted to the studio, where a lack of storage space meant that there was a good deal of carrying and fetching.

In many cases more than one photograph was taken of each object. The coins required two photographs - one of each side - except for the one-sided electrotype pins. Long inscriptions were photographed in sections, with the aim of being able to read the inscription on screen. Three dimensional objects were photographed at different angles. Some close-ups were taken of important details. The average number of photographs per object is between three and four.

Wherever possible, accession numbers or other identifiers have been included in each photograph (a few errors have been noted in the relevant database records).

Overall, a very high standard was achieved in the photography, despite the very long hours involved and a certain amount of pressure from time to time. Inevitably, some photographs turned out to be less than perfect in focus or lighting. There has not been time to go through and cull the relatively few less-than-perfect photographs and replace them.

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Source Media

At the start of the project it was decided that 35mm colour transparencies of the objects would provide higher quality primary sources than any other affordable media - it should be remembered that, at the time, both the world wide web and digital cameras were in their infancy. The transparencies would also be a useful addition to the Department's slide collection. It was further decided that contact prints would be needed to identify the object on its paper accession record in the University Gallery and in the Department files. The photography process has thus produced the following media containing unedited photographs:

The bulk of the project's funds was expended on photographic materials and processing. The transparencies have not been mounted in frames.

The images developed from the source media are stored on hard disks and DAT tapes. See below for further details.

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Image Production

For the Virtual Museum kiosk some 23,300 images have been produced. 9,205 of these are available on the web. There are, in addition, a few other images used by the website or as examples of the full potential of the project.

Images in the Virtual Museum have been developed by copying raw images from Kodak Photo-CDs and editing them using Adobe Photoshop. This is a very time-consuming task, even for basic editing such as cropping and rotating, and it is has been possible to automate only a few mechanical aspects of the process.

Stage one editing involves copying the raw image from the Photo-CD, cropping, rotating, resizing, applying a filter to compensate for resampling, and saving the edited image with a unique name.

Some images have been taken to a further stage of editing with the removal of shadows and background and adjustment of light and colour values. A few examples of stage 1 and stage 2 editing have been prepared for comparison. Editing to stage 2 generally takes between 8 and 15 minutes per image, though some can take longer. The speed and capacity of the computer being used is a significant factor, but it is still the case that each raw image needs to be individually edited.

One unfortunate consequence of the imaging process adopted - scanning from transparencies - is that the scanner has put a colour cast in most of the images. It is thus more than usually important for the quality of the final visual output of the project that the images be edited beyond stage 1. Even more unfortunately, this was one of the phases of the project that had to be jettisoned in the middle of 1998 when staff changes forced reduction of the project to a salvage operation.

Other Sources

A few images come from other sources. Photographs or negatives of missing objects and of objects in situ have been scanned and included in the Virtual Museum. One image of a missing papyrus has been supplied from Oxford University, to whom we sent copies of photographs in 1970 (the original photographs have not been found), and the Department's original hand-written transcriptions of the papyri have also been scanned. One image was taken directly with a digital camera. Images of the bronze cast of Poseidon (Zeus?) in the Old Pathology courtyard have been extracted from the object movie.

Transcriptions of texts in non-Latin scripts, both published and hand-written, have been converted into images. Some of these are called up from text files. Translations into English, as well as transcriptions of Latin texts, are text files but are kept with the images and listed in the images database.

Other Purposes

During the project a number of images were provided for various publicity publications. Some staff have asked for printouts to use in classes. Some 600 images will be needed for the planned printed volume and CD on the Greek Vases.

These images have to be prepared especially for the print media. Printers require the highest resolution possible, and from the source Photo-CDs it is possible to output at 288 dots per inch (for the on-line versions a screen resolution of 72 pixels per inch is the norm). Printers also require the images to be in the four colour CYMK format (the RGB format is more appropriate for computer screens). Colour images also need to be especially adjusted for black and white prints. The size of each image file supplied to a printer at the required specifications is in the order of 10 mb. This size far exceeds the capacity of the Virtual Museum's storage space. In any case, printed images have to be edited to the highest possible standard - beyond what is described above as stage 2. It was thus not feasible, during the course of the Virtual Museum Project, to develop edited images that would simultaneously serve both the print and on-line media.

On the other hand, images edited to the highest standard for printing can be quickly converted into the on-line format and size and substituted for the corresponding less edited images already included in Virtual Museum.

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Image Sizes

Images have been produced to fit three frame sizes: small, medium and large. This table indicates the jpeg compression specifications for each frame size and the image filename code:

Size

Filename code

Frame (pixels)

Quality

Baseline

Av. size

Small

g

342 x 256

6

standard

21k

Medium

k

685 x 512

8

optimized

102k

Large

x

1370 x 1024

10

optimized

880k

The small images fit within a frame of 342 x 256 pixels. For the web version of the Virtual Museum a small image size was needed to keep download times reasonable. The size adopted represents a compromise between a thumbnail and a screen-sized image. The size of the image as it displays on a monitor will vary according to the resolution of the monitor. On small, low-resolution monitors the small images will almost fill the screen:

Monitor resolution

Max. width

Max. height

640 x 480

16.3 cm

12.2 cm

832 x 624

12.6 cm

9.4 cm

1024 x 768

10.3 cm

7.5 cm

The medium sized images almost fill the large screen of the high-resolution kiosk monitor. Their frame is four times larger than that of the small web images.

The large size is sixteen times the smaller size and fills about four screens. This is about half the maximum possible (3072 x 2048 pixels uncropped), but 7-10,000 images of maximum size (average about 12 mb uncompressed) would have either massively exceeded hard disk storage capacity or necessitated a much higher compression ratio with loss of image quality.

A relatively small number of image files, produced early in the project, do not fit these specifications.

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Object Movies

The object movies were produced by the Multimedia Education Unit using a stand and gantry that was originally purchased primarily for the Virtual Museum Project. This equipment, which cost in the order of $20,000, was regarded by MEU as a strategic investment.

Slightly over 100 object movies have been produced for the Virtual Museum, at a cost of just over $10,000.

Most of the movies were produced by mounting the object on a stand that could be rotated a full 360 degrees on the horizontal plane at pre-determined steps of 10-15 degrees. A photograph of the object was taken at each step. The gantry held the camera at a fixed vertical angle for each rotation. The camera was then lowered by a fixed number of degrees on the vertical plane, and the object rotated once more. For most objects the vertical rotation is about 110 degrees.

Several stand tops were designed and constructed so that valuable fragile vases could be mounted on a more secure base. Much experiment was needed to identify the best combination of lighting and background for what are mostly round shiny black objects viewed from many angles - objects that present quite a challenge even for still photography.

Some objects were too large and heavy to be mounted on the stand and rotated. A method was devised of walking around the object rather than rotating the object. The resultant movies allow only horizontal rotation, there is no vertical rotation; but the file size is proportionally reduced.

The movies were composed by stitching together the 400 or so still images, using rather clever software. The resultant raw movie files are in the order of 800 mb - too big for a Photo-CD, so they have been archived on DAT tapes. The raw movie files were subsequently processed and compressed, and the resulting files average around 12 mb each. This file size is manageable on the kiosk and, with a good connection, on campus; they are somewhat impractical on the web, especially if the connection is by telephone modem.

The processed files have been archived on two Photo-CDs. Copies are included in the Virtual Museum in a "movies" folder kept together with the images folders.

In the Virtual Museum the movies are called by a text document which includes details of the object. It is this text document that is recorded in the Images Database and accessed like other image files. The movie file itself is thus not recorded in the Images Database, although the size given for the text document is in fact the size of the movie file.

MEU's David Adam has continued to experiment with object movie files and believes that they can be further processed down to an average of about 2 mb each. It will thus be possible to include all 68 movies of the Greek Vases on a single CD-ROM. Consideration is also being given to mounting all the movies on the web server.

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Image Folders and Filenames

Images are kept in a folder called 'pics'. On the website this folder contains about 70 individual folders named after the CD on which are found the source files from which the images in each folder have been derived. On the kiosk the 'pics' folder contains an additional 140 folders with the larger versions of the images. There is a 'k' or 'x' at the end of the name of the folders containing the larger versions, and the image filenames also have a 'k' or 'x' before the filename extension. The name of the enclosing folder is stored in the record of each image file registered in the Images database. As this folder name is used to identify the file path when displaying images in the Virtual Museum, any change in a folder name and any relocation of an image file would have to be recorded in the Images database.

The website 'pics' folder occupies 457 mb. The 'picsk' folders total 688 mb, while the 'picsx' folders total 6.7 gigabytes.

Image filenames are of the type xxxxxxxx.jpg, where x is an alphanumeric character. This type of filename has been chosen to meet the requirements of the Macintosh, DOS, Windows, and Unix computer operating systems and to convey certain information about the source, size, compression and quality of the image.

Exceptions to the above are:

1. Folder numbered 0000.

This contains images not derived from a CD but by some other procedure (direct digital photography, scanning from hard copy, received by email from someone, created from text).

Transcriptions and translations of texts (manuscripts, papyri) have filenames of the type xxxxyyyz.sss, where:

2. Multisession CD no. 0294.

Each session on this CD mounts as a separate volume with a nonstandard name, and the source image files also do not have standard filenames. The images database contains full details of the source filename and filepath of all images derived from these two sources; the images derived from these sources may have standardized filenames commencing with 0294.

3. Movies.

Object movies are all stored in the folders "movies" or "moviesx". Each object movie has a filename corresponding to the accession number of the object but without the dot that follows the date in the accession number. Movie filenames all have the extension ".mov". The html file that display the movie has the same name as the corresponding movie file, but with the extension ".htm". It is the html file that is recorded in the Images database, the actual movie file is not recorded. The size given for the html file is that of the corresponding movie file.

4. Earlier files.

These files were often created during the course of the project for specific purposes such as public demonstrations or various publications. Most of them do not match the standard image size specifications. Their filenames may have a dot after the first four characters and/or a dot before the pre-suffix letter, which may be a letter other than g, k or x. Examples are 1470.012.jpg, 2714.050.JPG. In most cases the editing has been taken to further stages: the background to the object has been edited, and/or the light and colour levels adjusted and various filters applied. Many are also linked to web pages devoted to specific aspects of the collection.
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Archiving and Storage

Some 50,000 images were created during the processing. Given that the raw images were in the order of 18 mb each, it became necessary to juggle gigabytes of image files across several hard disks and to process the Photo-CDs in batches of three or four at a time in order to allow regular backing up of work in progress. It was indeed fortunate that hard disk technology developed almost pari passu with the project and a set of 9 gb hard disks - unheard of when the project started - was employed to manage image processing and backing up.

The current 'product' - around 24,000 edited images and over 100 object movies - occupies some 8.5 gigabytes of storage space. These images represent a significant amout of work and 'added value' over the source Photo-CDs. When all images are edited to at least stage 2 it would be sensible to burn them on to Photo-CDs for archival purposes. In the interim, there is at least one backup on a separate external hard disk, and the entire product will be archived on two sets of DAT tapes at the conclusion of this phase of the Project.

Given the relatively poor record of DAT tapes, backing up the edited materials to DVD disks is under consideration. Indeed, anticipated development of DVD disks should make it possible in the near future to store the entire contents of the kiosk version on a single DVD disk, which could be made available for distribution.

Arrangements have been made to store the various archives and media in separate locations.

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