PASIG Bootcamp: Image Formats Robert Buckley NewMarket Imaging/ University of Rochester PASIG - Washington 22 May 2013

Introduction to image formats Summary Introduction to image formats Short List Container Formats Use Models under Short List

What is an image format? Application Format ImageStream Color Spec Metadata Format Application A Content Data Object and its associated Representation Information, part of an Information Package. OAIS Reference Model A serialized encoding of an abstract information model, which is a unit of exchangeable knowledge. Global Digital Format Registry A format is a set of semantic and syntactic rules governing the mapping between abstract information and its representation in digital form. Unified Digital Format Registry A package of information that can be stored as a data file or sent via a network as a data stream. Library of Congress/NDIIPP The internal structure and encoding of a digital object, which allows it to be processed, or to be rendered in human-accessible form. The National Archives Machine processing as an aid to human processing; are images fundamentally for human consumption

Sustainability Factors Library of Congress The National Archives Disclosure Adoption Transparency Self documentation External dependencies Impact of patents Technical protection mechanisms Ubiquity Support Disclosure Documentation quality Stability Ease of identification & validation Intellectual property rights Metadata support Complexity Interoperability Viability Re-usability Focus on format properties Sustainability for preservation This is for suppliers, providers, packagers who have to deliver content and user value www.digitalpreservation.gov/formats/sustain/sustain.shtml www.nationalarchives.gov.uk/documents/selecting-file-formats.pdf

System Sustainability Factors Cost Implementation User Experience Look at the format from the standpoint of the system – some overlap with previous slide Format forces an object focus Implementation includes workflow Taking a broader view of what they have to do and manage – add content to this list Format is this thing we have to implement and manage in a cost effective way to deliver user experience and customer value, with all the usual concerns about IP, security, etc. It’s really about the content. So what happens if you adopt a content-based approach? --------------------- http://www.cnn.com/2012/03/01/world/europe/ghent-altarpiece-online-open-source Consisting of 12 panels (one of which is a copy, the original having been stolen in 1934) and depicting numerous complex theological scenes, the documentation project has rendered the already composite work into 100 billion pixels using the highest resolution photography.

Originals Now talking about images Is it originals? To be digitized and end up as content – for what end? Access to a digital surrogate Digitization is implicit What about born digital? Raw on the left to TIFF/JPEG on the right, where rendering decisions have been made As you go from left to right, less interpretation – why any interpretation? Well, there’s ground truth and then there’s what you can render Think of it in terms of decisions © R.M.N./Arnaudet – J. Schormans

Image State Color Encoding Plus Image Encoding Metadata Encoding Scene- or original-referred Output-referred after a rendering decision Plus Image Encoding Uncompressed Losslessy compressed Lossy compressed (functionally lossless) Metadata Encoding Almost everything is digitization, except the computer generated images from CGI and office apps ICC has one node for output-referred, ACES has two: one for What do you make of this pile of bits First you need to decode it and produce a raster for rendering, display, print, etc. Image State 1, e.g. original referred, and 2, e.g. compressed – expand on concept Mention CIE study

Image Formats – Short List Format Family Format Year TIFF TIFF 6.0 + extensions 1992 JPEG Baseline 1993 PNG W3C & ISO/IEC version 1996 JPEG 2000 JP2 - base file format JPX, MJ2, JPM 2000 Raw CR2, NEF, DNG, … 2004 (DNG) PDF/A A-1, 2, 3 2005 Only one? Recall UConn save Raw + JP2 which together are smaller than an uncompressed TIFF Too listy – make into a table, e.g. Raw – DNG, CR2, NEF, …. For the time being, think of these as single image formats/containers So when all is said and done and you wrap it all up and listen to what people are saying, here are the formats that are being discussed when it comes to archiving and preservation. So let’s step back and think about use cases.

Production Master and Derivatives Use Models Archival Master Production Master and Derivatives Service File Uncompressed TIFF Multiple JPEGs JPEG Lossy JPEG 2000 JPEG, PDF Lossless JPEG 2000 Lossless JPEG 2000 + DNG Line 4 is UConn from Using DNG, JPEG 2000, and Embedded XMP Metadata at UConn.pdf in PASIG 2013 folder; their system produces JPEGs for the Interent Archive Bookreader http://openlibrary.org/dev/docs/bookreader Some talking about compression but short of JPEG 2000

Container Formats Format Contents TIFF Multiple page images PDF/A Multiple pages and page components JPEG 2000 - JPX Multiple images in x, y, z and t - MJ2 Timed image sequence - JPM Multiple pages and image components MXF Audio and video streams All have metadata Distinguish from packaging formats, such as ZIP, TAR and AXF (and BagIt) Supporting multiple codecs – all on this list do except JPX – check about audio in MJ2 For the time being, think of these as single image formats/containers

Multiple Images in a JPX Codestream

Multiple Images in an MJ2 file

MXF Digital Cinema Package (DCP) uses lossy JPEG 2000 for image content SAMMA migrates videotapes to MXF OP1a files with lossless JPEG 2000 image content FADGI A/V Working Group developing MXF AS-07 Application Specification for Archiving & Preservation

Wrap-up Only a small set of formats used for archival images There is a growing need for compression Expanding the notion of an image format JPEG 2000 as a bridge between still image and archival MXF formats Questions? rob@newmarketimaging.com About making a decision today—consequences for migration and emulation