Still Searching…

The conditions governing the digital world have led to a radical diversification not only in photography but also in the theory that underpins it and the history that is written about it. Photographic media and forms are incorporated into complex tech technological, capitalist and ideological networks; the experts who are conducting scholarly research into the role of photographic images thus come from very different disciplines. The expansion of the discourse surrounding these images is also reflected in Still Searching…, the blog on photographic theory that was initiated by Fotomuseum Winterthur in 2012 and which subjects all aspects of photography and its role in visual culture to interdisciplinary scrutiny. The bloggers invited to the online format operate at the forefront of research and enhance our awareness of current issues that are relevant to photography.

Blog series: Photo Forensics

Hany Farid | 15.10. – 15.12.2015
Photo Forensics

From October 15 until mid-December, Hany Farid will shed light on the ubiquity of image manipulation and the nature of trust in photography from the point of view of photo forensics. He will discuss digital forensic techniques used to detect various forms of tampering in visual material that he argues may have the potential to restore — at least partially — our faith in photography.

Photo Forensics: In the Shadows

Thursday, 29.10.2015
<p>When asked to judge the location of the sun relative to this scene, most people would respond quickly that it is on the right. When asked to localize the sun more precisely, most people would need to think before responding and they would still be inaccurate. (For evidence of this perceptual failure see <span class="frzfn fn"><span class="marker">1</span><span class="text">Hany Farid and Mary J. Bravo. Image Forensic Analyses that Elude the Human Visual System. <em>SPIE Symposium on Electronic Imaging</em>, San Jose, CA, 2010.</span></span>, but also test yourself: the answer is below.) The difficulty we have localizing light sources is surprising because the scene contains abundant information for making this judgment. The fact that we cannot easily perceive information that is clearly contained within the image provides an opening for forensic analysis because forgers may be unaware that they have introduced telltale clues that we can easily detect. In this post, we will see how to determine whether the cast shadows in an image are consistent with a single light source. If the shadows are inconsistent in a scene that is clearly illuminated by a single source (e.g., the sun), then we have strong evidence of image tampering.</p>