High Dynamic Range (HDR) imaging is a continuously evolving field of research, innerly linked to computer vision. More than twenty years ago HDR started to be popular with the seminal paper of Debevec and Malik proposing multiple exposures to attempt to capture a wider range of scene information. Today, the evolution continues in the current sales of HDR televisions using new technologies like OLED and Quantum Dot.

What makes HDR imaging a complex problem is that it is controlled by optics, signal-processing and human visual limits and each one of these factors plays a fundamental role. Moreover, more than one approach is possible to face HDR, and the solution depends on the chosen goal.

After a detailed description of the dynamic range problem, this course focuses on all the different possible goals of the HDR pipeline: reproducing light field, reproducing appearance, improving image aesthetic and visibility. For each goal a careful analysis of characteristics, limits and ground truth will be presented. The course aims at replacing myths with measurements about the limits of accurate camera acquisition (range and color) and the usable range of light for displays presented to human vision. It discusses the principles of tone rendering and the role of HDR spatial comparisons.

Short Bio

Alessandro Rizzi is Full Professor and head of MIPSLab, at the Department of Computer Science, University of Milan. He researches on color, HDR, and related perceptual issues. He is one of the founders of the Italian Color Group, Secretary of CIE Division 8, and IS&T Fellow and Vice President, topical editor of Journal of Optical Society of America, associate editor of Journal of Electronic Imaging. In 2015 received the Davies Medal from the Royal Photographic Society.

He presented tutorial on HDR at several conferences, like e.g. ICIAP, Color Imaging Conf., Electronic Imaging, etc.

On this topic he has published several papers and two books: 

  • J.J. McCann; V. Vonikakis; A. Rizzi, “HDR Scene Capture and Appearance”, SPIE Spotlight Series, Volume: SL35, Pages: 92, December 2017, ISBN: 9781510618541.
  • J.J. McCann, A. Rizzi, “The Art and Science of HDR Imaging”, John Wiley, ISBN: 978-0-470-66622-7, pp. XXV+389, (2011).