improving your image the ioe approach to quality assurance erpanet 23 - 25 june 02 victoria fenner,...

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Images of England a new photographic survey of England’s historic buildings, that will result in a digital image library with up to 370,000 images the digital library will be accessible to all via the internet, free of charge

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Images of England

• a new photographic survey of England’s

historic buildings, that will result in a digital

image library with up to 370,000 images

• the digital library will be accessible to all via

the internet, free of charge

Objectives

• Creating a digital image library for future generations, a ‘point in time’ record

• Making heritage information more widely available and accessible now

• Internet is delivery mechanism

Management

• £4.4 million project

• National Monuments Record, the public archive of English Heritage

Listed buildings

• Designated for: – architectural interest– historic interest– historical associations– group value– age and rarity

• 370,000 + separate ‘listings’

Listed Building System

• Created in a joint project between the

DCMS, English Heritage and Royal

Commission

• Source of indexing and architectural

descriptions for Images of England

• Not all buildings ….

19th century milestone,Creech St Michael, Somerset

Grade II

© Mick Humphreys LRPS

Telephone box & stamp machine, Whitley Bay, N Tyneside

Grade II

© MJ Saunders

The volunteers

• Army of volunteer photographers (>1,100 as of June 02)

• 35 mm cameras, colour negative film

• Providing photographic skills, local knowledge

The survey team

• Provide volunteers with film, a list of targets and supporting documents

• Brief them fully, including the standards expected

The defining image

• shows architectural character

• indicates function, where relevant

• shows something of a building’s context

• is a truthful image

• is of high technical quality

• provides visual information as well as being a ‘good picture’

Flowline

• Key relationship - link between the number of the listed build record, the film number and frame number

• Complex process, with 370,000 targets, 15,000 films and over 1,100 volunteers

• Essential to build in safety mechanisms

After photography

• Contractors process, print and scan

• IoE creates links between frames and films and the listed building records

Creation of digital originals

• Volunteers keep prints and negatives, digital originals are being created from 35 mm colour negative films

• Contractual specification of scanning requirements - resolution, colour depth and dynamic range, meta data etc.

Range of digital images

• Master set of images uncompressed TIFF files, archive only and available on demand

• Thumbnail, low, medium and high resolution JPEGs also created - first two only on website

Quality Assurance

• Digital images quality assured for:

– scan quality

– photographic quality

– establishing the right building has been photographed

Standards established

• Each image is given numerical score for scan quality and for photographic quality

• ‘Is it the right building’ - Pass or Fail

Scan quality

• Grades 1 and 2 only

• Grade 1 = pass = website

• Grade 2 = fail = re-scan or correct defect

Photographic quality

• How well does image meet the defining image criteria?

• Aims to be as objective as possible, to achieve a consistent standard

• Image QA guidelines drawn up

Defect codes

• Grade is determined by the presence and severity of ‘defects’

• Singly or in combination

• Grades 1, 2, 3 & 4

Photographic error codes

• Temporarily Obscured

• Differential Lighting

• Permanently Obscured

• Distorted• Cropped• Dull Image

• Framing/Composition

• Levelling

• Key Listed Features not visible

• Flare

• Vignetting

• Group Incomplete • Unidentified

• Camera Fault

• Focus

• Photographer’s Bits • Water/condensation on lens• Multiple Exposure

Archiving policy

• Different media

• Back-ups

• Migration policy

Variables at source

• Source photography– photographer skills– lighting and differential conditions

• Buildings themselves and locations

• Overcome by:– standards, guidelines, feedback, QA, review, audit

trail

Variables in digitisation process• Artefacts• High volume and high quality• Maintaining the workflow

– constant throughput vs. flexibility

• Overcome by:– standards, building quality into scanning

contract from outset, QA, change control

www.imagesofengland.org.uk

Thank you!