Digital holography

Digital holography is an inherently three-dimensional (3D) technique for the capture of real-world objects, and is unrivalled in high-end industry and scientific research for non-contact inspection of precision 3D components and microscopic 3D samples. Many existing 3D imaging techniques are based on the explicit combination of several 2D perspectives (or light stripes, etc.). The advantage of holograms is that multiple 2D perspectives can be optically combined in parallel in one step independent of the hologram size. Recently digital holography (holography using a digital camera) has become feasible due to advances in scientific camera technology. The advantage of a digital representation of holograms is that they can be processed, analysed, and transmitted electronically.

Digital holograms, as a new form of digital media, are now beginning to be processed and analysed like conventional images. The participants in this project have pioneered aspects of the capture and processing of digital holograms. As a generalisation of conventional images, digital holograms have greater potential for wider society than simply in high-end industry and scientific research. However, in order for the envisaged applications of holographic image processing (3D display and video, non-contact automated inspection, medical imaging, 3D microscopy, security, 3D computer games, and virtual reality) to become commonplace, it needs to be demonstrated that digital holography can come out of the laboratory and can be usefully and practically employed in day-to-day life.

 

Public abstract

Real 3D Digital holography for 3D and 4D real-world objects' capture, processing, and display

Current and newly-developed 3D displays have the disadvantage that they either force the user to wear special eyewear, limit the number of simultaneous viewers, discard completely certain depth cues (such as blurring) thus causing fatigue, or else encode only a small number of distinct different views of the 3D scene. It is universally accepted that there is only one known family of techniques that can capture a full 3D scene in a single shot, including phase information, and re-project that light field perfectly thus overcoming all of the above disadvantages: the broad family of holography techniques. All other techniques are only 3D under a whole host of conditions.

Unfortunately, conventional holograms are not dynamic. By replacing the conventional holographic plate with a digital camera and an optoelectronic 2D screen, we can capture and display holographic video. However, the full implications of bringing a digital version of holography into the world of 3D video acquisition and 3D display, or how effective it would be, are as yet unknown. The 3D information encoded in digital holograms has not yet been fully exploited.

We will work towards eliminating the current obstacles in achieving the world's first fully functional 3D video capture and display paradigm for unrestricted viewing of real-world objects that employs all real 3D principles, hence our acronym "Real 3D." Our outputs will include functional models of four digital holographic 3D capture, processing, and display scenarios encompassing (i) the full 360 degrees of perspectives of reflective macroscopic 3D scenes, (ii) microscopic reflective 3D scenes, (iii) transmissive or partially transmissive microscopic 3D scenes, and (iv) capture of 3D scenes at infra-red wavelengths.

 
 

The Real 3D project is funded by the
European Community's Seventh Framework
Programme FP7/2007-2013 under grant
agreement n° 216105