Why manipulate digital images?

Tinkering with the Truth Investigations into digital photograph manipulation and technologies of digital image credibility

We are all affected

Proposed Digital Photograph Authentication Framework

Output of forensic examination can only be that image is not authentic or is likely to be authentic. Forensics cannot verify authenticity.

The credibility or otherwise of digital images receives little attention at present, in fact it is considered standard practice by many digital photographers and other producers of digital images to ‘tinker’ with digital images prior to distribution. However, as time goes on, understanding the extent to which a digital image can be believed is becoming increasingly important as ‘enhanced’ digital images proliferate, and purport to represent the reality of individuals and our environments, record significant human events, and are used as supportive evidence in areas as diverse as academic research and law enforcement.

sabrina.caldwell@anu.edu.au Supervisory Panel: Tom Gedeon, Richard Jones, Marty Jolly

Courts and Law Enforcement

Sociologists and Historians

Scientists

Camera Manufacturers

Digital photographs as evidence increasingly problematic.

“By tampering with our malleable memory, [digitally

Kodak, Canon, Nikon and Epson have made failed attempts to introduce authentication systems, but efforts continue.

To exaggerate

In 2006, Reuters admitted that digital photographs presented as part of its coverage of the Israel-Lebanon conflict had been significantly altered using photo- editing software before being published. The photo above left was manipulated from the photo above right.

To vilify

In 1994, Time Magazine digitally manipulated O.J. Simpson’s mug shot to make him look more sinister.

Australian photograph “Yellow-tailed Black Cockatoos” passed on Flickr as real; photographer admits photo is same bird twice.

To imagine

2008, award-winning “Qinghai-Tibet Railway opening green passageway for wild animals” photo faked by Daqing Evening News photographer Liu Weiqing.

To propagandise

College of Engineering and Computer Science

In 2010, Journal of Cell Biology reports 25% of all

inappropriately manipulated; 1% are fraudulent or images and figures submitted to them are

misrepresentative.

doctored photographs] may ultimately change the way we recall history,” Dario Sacchi.

So what’s new?

Ability to manipulate images is in the hands of the many rather than the few.

In the future the period 1990’s to 2020’s or later may be known as the dark ages of photographs as ‘silent witnesses’ to truth/reality.

Ubiquitous photo manipulation leading to uncritical public acceptance of altered photos.

Authentication, not forensics

Authentication mechanism(s) produced at image capture

Identical

or equivalent

Unmodified proof

layer(s)

Modified proof

layer(s)

Compare

Digital Image from Unknown Source

• Near-duplicated image regions • Splicing w/ w/o resampling • Discerning photorealistic computer graphics • Compression properties • Inconsistent sensor artefacts • Inconsistent lighting • Local noise • Blur inconsistencies • DCT, DWT analyses

Yellow-tailed Black Cockatoos Photographer: John Smith

F-stop Aperture Date and Time

Creative Commons Licence NLA archive accession #J34X8

Wrapper file format (all layers visible)

Original digital photograph proof layer

Original digital photograph presentation layer

Presentation

Proof

Provenance

Yellow-tailed Black Cockatoos Photographer: John Smith

F-stop Aperture Date and Time

Creative Commons Licence NLA archive accession #J34X8

Wrapper file format (all layers visible)

Original digital photograph proof layer(s)

Modified presentation layer

Presentation

Proof

Provenance

Presentation layer can easily be compared to proof layers. Photo artists can show their sources Photo manipulations become evident

No proof layer highlights ‘presence of absence’ and photo cannot be authenticated Proof layer can be copy, authentication string or similar, e.g. accession # of collecting institution

Provenance layer can contain easily accessible metadata Can hold range of contextual information

Physicians Inappropriately altered photographs could result

in misdiagnoses.