A SIFT features based blind watermarking for DIBR 3D images

Three-dimensional (3D) images consisting of arrays of voxels can now be routinely obtained from several different types of microscopes. These include both the transmission and emission modes of the confocal scanning laser microscope (but not its most common reflection mode), the secondary ion mass spectrometer, and computed tomography using electrons, X-rays or other signals. Compared to the traditional use of serial sectioning (which includes sequential polishing of hard materials), these newer techniques eliminate difficulties of alignment of slices, and maintain uniform resolution in the depth direction. However, the resolution in the z-direction may be different from that within each image plane, which makes the voxels non-cubic and creates some difficulties for subsequent analysis.

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Developments in 3D Echocardiography

European Cardiology Review ◽

10.15420/ecr.2009.5.2.10 ◽

2009 ◽

Vol 5 (2) ◽

pp. 10 ◽

Cited By ~ 1

Author(s):

Jose Luis Zamorano ◽

Keyword(s):

3D Echocardiography ◽

Resonance Imaging ◽

Clinical Tool ◽

3D Images ◽

Processing Power ◽

2D Echocardiography ◽

Automated Quantification ◽

Heart Cycle ◽

Functional Mechanisms ◽

Full Volume

3D echocardiography (3DE) will gain increasing acceptance as a routine clinical tool as the technology evolves due to advances in technology and computer processing power. Images obtained from 3DE provide more accurate assessment of complex cardiac anatomy and sophisticated functional mechanisms compared with conventional 2D echocardiography (2DE), and are comparable to those achieved with magnetic resonance imaging. Many of the limitations associated with the early iterations of 3DE prevented their widespread clinical application. However, recent significant improvements in transducer and post-processing software technologies have addressed many of these issues. Furthermore, the most recent advances in the ability to image the entire heart in realtime and fully automated quantification have poised 3DE to become more ubiquitous in clinical routine. Realtime 3DE (RT3DE) systems offer further improvements in the diagnostic and treatment planning capabilities of cardiac ultrasound. Innovations such as the ability to acquire non-stitched, realtime, full-volume 3D images of the heart in a single heart cycle promise to overcome some of the current limitations of current RT3DE systems, which acquire images over four to seven cardiac cycles, with the need for gating and the potential for stitch artefacts.

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Full-parallax 3D display using time-multiplexing projection technology

Electronic Imaging ◽

10.2352/issn.2470-1173.2020.2.sda-100 ◽

2020 ◽

Vol 2020 (2) ◽

pp. 100-1-100-6

Author(s):

Takuya Omura ◽

Hayato Watanabe ◽

Naoto Okaichi ◽

Hisayuki Sasaki ◽

Masahiro Kawakita

Keyword(s):

Incident Light ◽

Polarization State ◽

3D Image ◽

3D Display ◽

Time Division Multiplexing ◽

3D Images ◽

Polarization Gratings ◽

Light Rays ◽

Time Division

We enhanced the resolution characteristics of a threedimensional (3D) image using time-division multiplexing methods in a full-parallax multi-view 3D display. A time-division light-ray shifting (TDLS) method is proposed that uses two polarization gratings (PGs). As PG changes the diffraction direction of light rays according to the polarization state of the incident light, this method can shift light rays approximately 7 mm in a diagonal direction by switching the polarization state of incident light and adjusting the distance between the PGs. We verified the effect on the characteristics of 3D images based on the extent of the shift. As a result, the resolution of a 3D image with depth is improved by shifting half a pitch of a multi-view image using the TDLS method, and the resolution of the image displayed near the screen is improved by shifting half a pixel of each viewpoint image with a wobbling method. These methods can easily enhance 3D characteristics with a small number of projectors.

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