Generation of digital textured surface models from hologram recordings

Abstract

Digital sensors and fast digital image processing facilitate the use of pulsed holography for 3D surface measurement of moving objects. The real image of a hologram is reconstructed optically. A sequence of high-resolution projection images of the real image with a varying distance to the hologram is recorded digitally. Focus detection in this image sequence by digital image processing yields the shape of the recorded object. The image intensity serves as a precise pixel-matching texture. An application of this concept is the generation of a textured 3D computer model of a facial surface from a portrait hologram.

Extended focused imaging for digital holograms of macroscopic three-dimensional objects

“…We are in the process of parallelizing our DFF algorithm to address the lengthy time required for computing a depth map. Objects can be illuminated with a speckle pattern to increase the accuracy of depth estimation [50], specifically in the case of objects with little or no texture. This EFI creation technique would be suitable for human viewer applications and machine vision applications where the approximate object edges are sufficient (e.g., some object recognition applications).…”

Holographic Printing of White-Light Viewable Holograms and Stereograms

“…The quality of the recording depends on the dynamic range of the photo-sensitive material [38]. The main disadvantage of this method is the cross-talk between the separate color channels [46]. In the second method a space division of exposures for the primary colors is applied which, however, decreases three times the diffracted intensity.…”

Holographic topometry for a dense visualization of soft tissue for facial reconstruction

“…In this study we capture the holographic recording from a single perspective, which means that the view is limited to the directly visible field. The field of view may be further extended by the introduction of mirrors [14]. There we recorded three perspectives simultaneously in one holographic recording.…”

“…At the identified surface point, the brightness information is extracted [14]. Such, one obtains a 2d monochromic representation I(x,y) of the surface texture beside the surface point.…”