Creating and delivering digital collections

University of Brighton 9 July 2010

John Hargreaves

JISC Digital Media

JISC Digital Media is a JISC funded service set up to provide advice and guidance predominantly to the Further and Higher Education community on the issues of creating, delivering and using still images, moving images and sound resources, together with managing digitisation projects.

JISC Digital Media’s Services

– Web resourceshttp://www.jiscdigitalmedia.ac.uk/

– Helpdesk serviceinfo@jiscdigitalmedia.ac.uk

– Hands-on traininghttp://www.jiscdigitalmedia.ac.uk/training/

– Mailing listhttp://www.jiscdigitalmedia.ac.uk/mailing_list.html

– Bloghttp://www.jiscdigitalmedia.ac.uk/blog/

– Online surgeries– Consultancy

http://www.jiscdigitalmedia.ac.uk/consultancy.html

Content for today:

• Tasks to undertake in planning a departmental image collection

• Handling originals• Review of key image properties and

formats• Calibration of monitors• File formats• Storage and delivery• Putting it all together

Why build a digital collection?

– Expensive

– Time consuming

– Steep learning curve

– Standards not always clear or stable

– …

Why build a digital collection?

– Required for teaching or research

– Improve access/ distribution

– Publicise resources

– Preservation

– Generate income

– Efficiency(avoid duplication)

– Staff development

– Attract staff/students

– Collaboration

– Demand from managers

– Demand from users!

Planning a Departmental Collection

Image courtesy of stock.xchng

Why not just get on with it?

”Our model of ‘just do it’is about to do us in.”

University of Oregon Librariesin RLG DigiNews, December 2005

Before you start….

Do your homework…– What do your users need?

(ask them)– What’s possible?

(what are others in similar situations doing?)– What resources do you have?

(e.g. existing images, metadata, technologies, skills, budget, time, goodwill… esp. from IT departments)

– What about the bigger picture?(e.g. institutional objectives, educational trends, legal context, other collections…)

Have a cunning plan…

– Set clear and achievable objectives

– Get it all down on paper(user requirements, technical specifications, workflow, timetable, budget, marketing, risk analysis, quality plan…)

– Involve any stakeholders

Particular things to think about…

– How important are ‘standards’?• E.g. image quality, metadata

– Do you want to ‘interoperate’?• Who might you share your collection with?

– Should you Do-It-All-Yourself?• Outsource all or some of the project?

– Copyright!!!• Thorough investigation is necessary before

starting the project

Handling Originals

What type of Original?

• 2D • 3D• Macroscopic• Microscopic• Primary source • Surrogate

Preparation of Originals

• Prior to digitisation…• Consider environment, software and

equipment• Establish a capture workflow• Agree with conservation that objects

are in a stable state• Ensure objects can be provided at

sufficient rate• Clean originals

Issues to Consider

• Access• Impact of capture conditions• Special requirements

• Fragile• Unsafe• Awkward

• Additional resources• Added time to workflow

How Should your Original be Handled?

• Is it suitable for being pressed on a flat bed scanner?

• Is it suitable for disbinding?• Slides and photographs should be

handled carefully and always by their edges

• Do not drag materials across scanner glass

Outsourcing Capture

• Maybe more cost effective to outsource the digitisation of large quantities or fragile originals

• Consultancy– Advise clients how to optimise in-

house resources for digitisation projects

Digital Images

Image courtesy of stock.xchng

Resolution– Best to think about absolute number of pixels in

your images rather than thinking in terms of dpi – unless scanning or printing.

8 samples

8 samples

32 samples

32 samples128 samples

128 samples

256 samples

256 samples

Image: JISC Digital Media

What Resolution is right?– Depends entirely on context

– Digital capture resolution:• Scanning large photos at 600 dpi on a flatbed is generous

• Scanning slides at 600 dpi is insufficient

– Digital output resolution:• A 600 pixel image might fill much of a laptop screen or

PowerPoint slide

• A 600 pixel image will only be 2 inches long printed at 300dpi

An Image Output to a Monitor

6 x 4 inch photo

sampled at 100 pixels per inch

How big?

600 x 400 pixels

How big on screen?

Depends on screen size (setting)

1024

768

800

600

300 dpi

6 x 4 inch photo sampled at 100 pixels per inch

How big?• 600 x 400 pixels

How big when printed?

Image when printed

Bit Depth – What you should know

– Every pixel is represented by one or more ‘bits’– Bits are binary and have only two values “0” or “1”– For a 1-bit image each pixel records either a single“0” or a “1”.

This gives a “bitonal” image. E.g. “0” = Black and “1” = White– The more the bits you allow for each pixel, the bigger the tonal

range (and the bigger the file)– 8 bits per pixel will enable 256 possible values, creating the

impression of continuous tone (“grayscale”)

Bit Depth – “Bitonal” to “Grayscale”

1-bit(2 shades)

2-bit(4 shades)

4-bit(16 shades)

8-bit(1 byte)(256

shades)

Images: JISC Digital Media

What about colour?

“24-bit colour” = 8-bits per colour channel

(256 shades of Red x 256 Greens x 256 Blues)

= 16.8 million potential colours

=

Images: JISC Digital Media

Calibrating your Monitor

Monitor Calibration:

• The process of correcting the colour rendition settings of a monitor to match desired colours of the output device.

• Away from bright light sources that might reflect off your screen

• A consistent ambient lighting• A neutral environment and a neutral (grey)

desktop

Calibration Hardware

•There is a small range of optical hardware available.

•These devices attach to the screen and read the monitor output

•They compare measured values from the screen with “known” values

•A profile is created and loaded into the OS to compensate for differences

Storing and Delivering

Your Collection

Image courtesy of stock.xchng

File Formats– Different formats suit different kinds of images

and different tasks:

– Established formats:• TIFF – high quality, holds 48-bit+ colour, suitable

for archiving, not suitable for Web delivery• JPEG – compromised quality, holds up to 24-bit

colour, ideal for photo-realistic images, Web delivery, care needed when compressing images

• GIF – simple format, only hold up to 256 colours (8-bit), ideal for graphics with flat colour, Web delivery

• And newer formats……

File Formats– Newer formats

• RAW and DNG formats – effectively digital negatives

• JPEG 2000 and PNG formats – next generation JPEG and GIF – suitable as both archiving and delivery formats due to lossless compression and higher bit-depths

File Naming– Several different options:

• Meaningful names(e.g. french_expedition_2005_01.jpg)

• Unique identifiers (e.g. 00000023.tif)

• A mix of both (e.g. 05a0001t.gif)

• Append original names if relevant (e.g. roman_vase_08579.Cr2 or roman_vase_08579_opt.tiff)

• My own choice (081107_BDICgrp_01392_kilbey.ext)

Photograph courtesy of stock.xchng

Automating tasks for your collection

– Photoshop, Lightroom (and some other programs) will let you batch process large quantities of images

– Useful for:• Adding common/shared metadata• Performing ‘universal’ edits such as changing

file formats

What metadata to collect

• Descriptive/ Discovery metadatae.g. “Title”, “Subject”Used for finding resources

• Admin, technical, preservation metadata

e.g.”Format”, “File size”Used to create, manage and preserve

resources

What metadata to collect (cont)

• Structural and packaging metadatae.g. “is part of”, “Master image locator”Used to organise resources

• Usage and contributed metadatae.g. “Published in”, “Licensed to”

Used for license purposes

What metadata to collect (cont)

• A Funder might require specific metadata

Images for Education

http://imagesforeducation.org.uk/

Vocabularies

• Why use them?

• Ways to control vocabularies

Why use controlled vocabularies?

• Better retrieval• Improved cataloguing efficiency and

consistency• ‘Disambiguate’ the language e.g. ‘bank’• Put things in their place e.g. classify,

identify relationships• Support interoperability and improve cross

searching and metadata sharing

Ways to control vocabularies

• Data entry rules• Formal subject headings• Thesauri• Classifications• Authority lists (people, places, events)• In-house keyword lists• ‘Free’ keywords added by a cataloguer• Combination of approaches

Storing and Delivering

Your Collection

Image courtesy of stock.xchng

Requirements and Resources

– Your choice of a system will be determined by your requirements and resources:

• What does it need to do?• How soon do you need a system?• Does your system need to integrate

with other systems?• How much can you afford to pay?• Do you have access to good IT support/

programming?• …

‘Low-tech’ Approaches– Careful file and folder naming– Spreadsheets– Metadata embedded within the image file– Simple ‘folder viewers’

(e.g. Windows folder view…

‘Low-tech’ Approaches– Free or cheap to buy

– but might prove expensive in terms of time(few productivity features)

– Quick and (fairly) easy to implement – though might add time later on(e.g. migrating data to another system)

– May be:(a) all you need for now, (b) an interim solution, or (c) something to use alongside other systems

‘Off-the-shelf’ Solutions– Commercial Image Management Systems

• Large range of products(Canto Cumulus/Mediadex, Extensis Portfolio, Fotostation, Imatch, Expression Media…)

• Often deal with more than just images(“digital asset management” systems – DAMs)

• Often come in a range of sizes and prices (standalone, server/workgroup, Web publishing…)

• Usually come from outside education/heritage sectors (e.g. business, photographic market)

Image courtesy of stock.xchng

Custom ‘Solutions’– Get someone to build you a system:

• Sometimes built using standard database and Web technologies

• Sometimes proprietary systems tailored to meet your specific needs

– Pros and cons:• Might be better match for your requirements, but

might not offer all the functionality of an off the shelf system at a similar cost

• Likely to take a lot of time and management• Can be issues with documentation, ongoing support

and upgrading the system

Image courtesy of stock.xchng

Using Existing Systems

– Manage your departmental collection using another system within your institution:

• Proprietary library, archive and museum management systems typically now offer image/media modules

• Repository Systems (e.g. DSpace)• Content Management Systems• Virtual Learning Environment (VLE) …

– Pros and cons:• Might solve your problems and open your collection

to wider audiences, but likely to be political issues, technical limitations, or compromises

Image courtesy of stock.xchng

Putting it together

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‘Workflow’

Useful to list (or draw diagram of) all the steps involved in adding images to your collection

Make sure you consider documentation required to support all these steps (e.g. selection criteria, cataloguing notes)

Make sure you build quality assurance (QA) checks into the workflow

‘Workflow’– JISC Digital Media’s sample QA workflow

http://www.jiscdigitalmedia.ac.uk/advice/creating/qassurance.html

‘Workflow’

You should QA both images and metadata (though not necessarily 100%)

Make sure you’re fully exploiting the technology (e.g. batch processing, metadata templates, automated spell-checking, calibrated monitors…)

Don’t expect anyone to scan or catalogue 7 hrs a day, 5 days a week…

‘Workflow’ Artists/Photographers don’t

necessarily make the best image editors

Subject experts don’t necessarily make best cataloguers…

…nor do librarians Consider how you might also exploit

your users (QA, metadata tagging, Web 2.0…)

Keep in Touch –Further Support and Guidance

• Web site: www.jiscdigitalmedia.ac.uk

• Helpdesk: info@jiscdigitalmedia.ac.uk

• Mailing list:www.jiscmail.ac.uk/lists/jiscdigitalmedia.html