Calimera Guidelines

The European Union has declared that “Digitisation is an essential first step to generating digital content that will underpin a fully digital Europe. It is a vital activity in preserving Europe’s collective cultural heritage, providing access for the citizen to that heritage, to enhancing education and tourism, and to the development of eContent industries.” It is committed to co-ordinating national digitisation programmes, and published the Lund Principles [1] which led to the Lund Action Plan [2] .

The Minerva Project [3] was set up in 2002 to promote a shared methodology for the digitisation of cultural material and to facilitate the adoption of the Lund Action Plan.

The benefits of digitisation include wider and easier access, the conservation of originals, the possibilities of adding value to images and collections, and opportunities for income generation (see the guideline on Business models). Digitisation can also publicise materials and attract greater numbers of visitors and users.

Digitisation is the process of creating digital files by converting analogue materials. The resulting digital copy, or digital surrogate, is then classed as digital material and is subject to the same broad challenges involved in preserving access to it, as "born digital" material (material created in digital format which has no analogue equivalent). The quality of the file, the format used to store it, its description, its intended use, its long-term preservation, the method of delivery to end users, and protection from infringement of intellectual property rights, are just some of the things which must be considered. Furthermore for each type of material that is digitised specific factors must be taken into consideration to make sure that the digital output can be used to its full potential now and in the future.

Staffing implications need to be considered. The importance of professional curatorial skills in ensuring original materials are not damaged during a digitisation project cannot be overemphasised. A digitisation project might provide a good opportunity to carry out any necessary conservation work. Protection such as gloves and masks might be needed. Staff will need training in the technical aspects of digitisation; even if the actual work is outsourced they will need to understand the procedures. Staff will also need training in the use of the end product, and in helping users. They will need new skills to work in the digital environment, as enquiries will increasingly be received electronically and new groups of users who have historically not used traditional services may now require a service. The skills needed will include technical, design, marketing, and instructional skills.

Digitisation projects create opportunities for partnership working with other cultural heritage institutions and with commercial organisations (see the guideline on Co-operation and partnership). These can include bringing together resources to create new virtual collections, sharing expertise and/or equipment, and working with software developers and suppliers. Collaboration with educational organisations and/or community groups can also result in the creation of “born digital” resources.

GOOD PRACTICE GUIDELINES Back to Scope

The Minerva Project has produced a Good Practice Handbook [4] and technical guidelines [5] which set out practical guidelines for a digitisation project.

Digitisation is the process of creating digital files by converting analogue materials. The resulting digital copy, or digital surrogate, can then be classed as digital material and is subject to the same broad challenges involved in preserving access to it, as "born digital" materials.

Planning and workflow Back to Scope

It is important to plan the project carefully and thoroughly (see the guidelines on Strategic planning and Business models). The plan should include:

· the reason(s) for digitisation, e.g. to provide access to underused holdings, to protect fragile items from the wear and tear of handling, to create a virtual collection, to target a specific group of users, to contribute to a regional, national or international network;

· what is to be digitised. This will be largely determined by the reason(s) for digitisation and whether permission to digitise can be obtained from the rights holders (see selection below);

· who will carry out the work. This could be in-house staff, specialist staff on a temporary contract, staff from a partner organisation, or a commercial contractor. Staff involved may need protection such as gloves, masks, etc. Curator staff familiar with the materials should always be used for any moving and handling especially of fragile items. (This might also be an opportunity to carry out any conservation work.);

· where the work will be done. In most cases it will be preferable to do the work on site to avoid risks such as loss or damage to originals, transport costs etc. Ideally a dedicated space should be made available taking into account lighting conditions, temperature, humidity, etc., especially when fragile originals are being digitised ;

· when it will be done. Consideration should be given to known busy times, staff holidays, special exhibitions or other events or projects. A timetable should be drawn up with milestones indicated;

· how it will be done. This part of the plan should include workflow details as it is essential to keep track of the material being digitised, and of progress. A system of listing, signing and dating all movements would be useful. Files should be named during the digitisation process;

· a preservation strategy. This needs to be in place from the planning stage to ensure sustainability and long-term usability of the collection. Preservation will depend upon documenting all of the technological procedures that led to the creation of the digital object, and much critical information can be captured only at the point of creation (see the guideline on Digital preservation);

· other considerations needed at the planning stage include legal issues such as IPR (Intellectual Property Rights), choice of digital formats, hardware, software, delivery methods or output formats and of course costs.

Financial considerations Back to Scope

Digitisation can be costly and local institutions may need to seek ways to augment their core funding by for example:

· lobbying and advocacy at national and local levels;

· influencing public opinion and forming groups of friends;

· applying for grant funding for a specific digitisation project. The last few years have seen the rise of a bidding culture in museums, libraries and archives in many countries. Governments, the EU, charitable trusts and other bodies or foundations have chosen to channel funds through competitive tender or submission of a bid. National professional associations should be able to advise on sources of funding. The Europa website contains a guide to EU funding opportunities [6];

· partnership with other institutions to outsource the work involved (see the guideline on Co-operation and partnership);

· some form of income generation. Some countries will be restricted by statute as to whether or not they are allowed to raise income or make any charges for services, including added value services. (See also the guideline on Business models.)

The amount and type of material to be digitised may be dependent on the funds available and decisions may have to be taken on what should have priority. This could be based on the aims of the project (preservation or increased access) rarity or value of the originals, the condition of the originals, the potential usage etc.

Comparatively low cost options may be adequate for some purposes. For example digital cameras, scanners etc. intended for the domestic market may produce results of sufficient quality for small community projects.

Selection Back to Scope

Selection criteria will, as stated above, be largely determined by the aims of the project, but may also include for example:

· legal issues such as whether it is possible to obtain permission to copy if needed (see the section on IPR below and also the guideline on Legal and rights issues);

· the target audience;

· the importance of the items in the cultural heritage of the community, region, country, Europe or the world;

· the rarity of the items;

· the condition of the items and the need for preservation of the originals by making digital versions available as an alternative;

· links to other projects;

· financial issues such as the need to raise income by charging for use or the sale of CD-ROMS, value for money, and costs.

Hardware and software Back to Scope

These should be chosen at the planning stage, taking into account reliability, costs, ease of use, staff training needs, maintenance costs, space available, possibilities of renting, etc. Equipment should enable recording and storing to be carried out at the highest possible resolution because a lower resolution image, or smaller file, can be extracted from a higher quality, higher resolution image, but never the other way round. The storage implications should also be taken into consideration, as higher resolution images create larger files and require more storage space.

The equipment must be suitable for the material to be digitised. The following points need to be taken into consideration:

Scanners

· flatbed scanners should only be used for unbound printed material or documents;

· bound items will require a book cradle or digital camera;

· the scanners should ideally be at least as large as the largest item to be scanned to avoid folding and “mosaicing”.

3D scanning devices

· these may be used for museum objects or historic buildings.

Digital cameras

· cameras may be used for museum objects or for bound books etc.;

· cameras may be used to record events, buildings, sites and landscapes;

· to get good picture quality the number of pixels, the bit-depth, and the optical lens quality are important;

· a stand for holding the material to be photographed will be useful;

· a tripod will be needed for the camera;

· supplementary lighting will in most cases be needed;

· filters will be required to reduce colour distortion.

Video cameras

· equipment will be needed for capturing digital output from conventional film and video;

· video recording equipment is used for capturing moving images and as such will be required for content creation projects resulting in “born digital” material;

· it is also a powerful tool for presenting a continuous view of all sides of an object, or for showing a three-dimensional space;

· the availability of comparatively cheap digital video camera equipment makes this sort of presentation possible for smaller institutions, mainly museums or galleries, which cannot afford the equipment to create full virtual reality content.

Audio recording equipment

· equipment will be needed which can produce digital output from analogue media;

· it is also used for capturing sound (speech, music etc.) and as such will be required for content creation projects resulting in “born digital” material;

Software Back to Scope

Software may be required to process the digital output e.g. correcting the colour of digital images, cropping the edges or compressing the file for web delivery. Such software should be capable of;

· opening very large files;

· modifying resolution and colour depth;

· saving different versions in different file sizes;

· copying part of an image and saving it as another file;

· exporting images in different file formats.

Selection of suitable software must take into account the material being digitised, for example if documents contain handwritten material then an OCR (optical character recognition) package will be required.

The TASI (Technical Advisory Service for Images) website contains advice on all aspects of digitisation, including hardware and software. [7]

File formats Back to Scope

The image or output produced by the digitisation process will be held in a particular file format. It is advisable to keep master copies and delivery copies in different formats.

It is preferable to use open standard formats when creating digitised resources to ensure that resources are reusable and can be created, modified and delivered by a variety of software applications. This will increase interoperability and therefore access, will reduce dependency on one supplier, and will help to guard against obsolescence. Master copies should be in a format which supports large, high quality images (e.g. TIFF (Tagged Image File Format) for photographic images).

For delivering resources it is preferable to use more than one format in different sizes and resolutions, bearing in mind that users will have different types of hardware and software and different levels of bandwidth. Delivery copies will usually be in smaller files suitable for transmitting over the Internet (e.g. JPEG, PNG (Portable Network Graphics) or GIF (Graphical Interchange Format) for still images). For more details see Standards below.

Standards Back to Scope

Standards are very important as failure to use standard file formats and storage media can:

· be a major obstacle to international exchange of image files and the creation of networked resources;

· lead to obsolescence (compliance with standards is a reasonable indicator of future support of a format or medium).

Different standards exist for different types of digital formats, and for capture and storage and delivery.

· Text capture and storage - There are standards for:

° character encoding (see Jukka Korpela: A tutorial on character code issues [8]);

° document formats (see AHDS Guide to good practice: creating and documenting electronic texts [9]).

· Text delivery - Again, for guidance on character encoding see Jukka Korpela’s article [8]. For document formats the latest versions of XHTML or HTML are advisable, though proprietary formats such as PDF (Portable Document Format), RTF (Rich Text Format) or Microsoft Word may be appropriate as alternatives. See:

° HTML 4.01 HyperText Markup Language [10];

° XHTML 1.0 Extensible HyperText Markup Language [11];

° Portable Document Format (PDF) [12].

· Still image capture and storage – Still images are raster (for photographs), vector (for geometric objects or shapes) or graphic non-vector (for line drawings). For advice see TASI: Advice: Creating digital images [13].

° When creating raster images the spatial resolution (pixels per inch) and colour resolution (bit depth) must be considered, and the highest affordable is preferable. TIFF (Tagged Image File Format) [14] is the most common.

° For vector images an open format such as SVG (Scalable Vector Graphics [15] should be used. The proprietary format Macromedia Flash [16] may be appropriate in some cases.

° PNG (Portable Network Graphics) [17] is the most common format for graphic non-vector images.

· Still image delivery

° Photographic images delivered via the internet must be in JPEG (Joint Photographic Expert Group) format [18] or JPEG/SPIFF (JPEG Still Picture Interchange File Format) [19]. More information is available about JPEG [20] and about JPEG 2000 [21] and there is an ISO standard [22].

° Vector images should be delivered using:

– GIF (Graphics Interchange Format) [23];

– PNG (Portable Network Graphics) format [24];

– or, SVG (Scalable Vector Graphics) format [25].

· Video image capture and storage – Video should be stored using the uncompressed raw AVI (Audio Video Interleave) format [26], but an MPEG (Moving Pictures Expert Group) format [27] can be used, or even Microsoft WMF (Windows Media Format), Microsoft ASF (Advanced Systems Format) or Apple Quicktime (details available on proprietary web pages [28]). Standards are available on the MPEG website [29].

· Video delivery – It must be remembered that access to video is affected by bandwidth so it is advisable to provide more than one file format or streaming quality.

° Video intended for downloading should be in MPEG-1 format [30] , or Microsoft WMF (Windows Media Video), AVI (Audio Video Interleave) or Apple Quicktime (details available on proprietary web pages [28]).

° Video for streaming should be in Microsoft ASF (Advanced Streaming Format), WMF or Apple Quicktime (details available on proprietary web pages [28]).

· Audio capture and storage – Audio can be stored either in:

° uncompressed formats such as Microsoft WAV (wave) or Apple AIFF (Audio Image File Format) (details on proprietary web pages [28]);

° or in compressed formats such as MP3 [31], Microsoft WMA (Windows Media Audio) format [28], Real Audio [32] or Sun AU [33].

The Audio Engineering Society (AES) [34] and the International Association of Sound and Audiovisual Archives (IASA) [35] make recommendations which should be considered.

· Audio delivery – As with video, access is affected by bandwidth so a range of files or streams of different quality should ideally be provided. The recommendations of the AES [34] and IASA [35] should be followed.

· 3D capture and storage – Digitisation of three-dimensional material is particularly important for museums. Digital video is a low-cost alternative to the creation of true 3D models, but is of course more limited in the range of interactive possibilities. For a discussion of 3D technologies see the websites of the Web 3D Consortium [36] or 3dsite, inc. [37].

· 3D delivery – VRML