Object-based 2D-to-3D video conversion for effective stereoscopic content generation in 3D-TV applications

Three-dimensional television (3D-TV) has gained increasing popularity in the broadcasting domain, as it enables enhanced viewing experiences in comparison to conventional two-dimensional (2D) TV. However, its application has been constrained due to the lack of essential contents, i.e., stereoscopic videos. To alleviate such content shortage, an economical and practical solution is to reuse the huge media resources that are available in monoscopic 2D and convert them to stereoscopic 3D. Although stereoscopic video can be generated from monoscopic sequences using depth measurements extracted from cues like focus blur, motion and size, the quality of the resulting video may be poor as such measurements are usually arbitrarily defined and appear inconsistent with the real scenes. To help solve this problem, a novel method for object-based stereoscopic video generation is proposed which features i) optical-flow based occlusion reasoning in determining depth ordinal, ii) object segmentation using improved region-growing from masks of determined depth layers, and iii) a hybrid depth estimation scheme using content-based matching (inside a small library of true stereo image pairs) and depth-ordinal based regularization. Comprehensive experiments have validated the effectiveness of our proposed 2D-to-3D conversion method in generating stereoscopic videos of consistent depth measurements for 3D-TV applications

Baseline and triangulation geometry in a standard plenoptic camera

In this paper, we demonstrate light field triangulation to determine depth distances and baselines in a plenoptic camera. The advancement of micro lenses and image sensors enabled plenoptic cameras to capture a scene from different viewpoints with sufficient spatial resolution. While object distances can be inferred from disparities in a stereo viewpoint pair using triangulation, this concept remains ambiguous when applied in case of plenoptic cameras. We present a geometrical light field model allowing the triangulation to be applied to a plenoptic camera in order to predict object distances or to specify baselines as desired. It is shown that distance estimates from our novel method match those of real objects placed in front of the camera. Additional benchmark tests with an optical design software further validate the model’s accuracy with deviations of less than 0:33 % for several main lens types and focus settings. A variety of applications in the automotive and robotics field can benefit from this estimation model

The use of convergent photography in high altitude reconnaissance.

Thesis (M.A.)--Boston Universit

Defocusing digital particle image velocimetry and the three-dimensional characterization of two-phase flows

Defocusing digital particle image velocimetry (DDPIV) is the natural extension of planar PIV techniques to the third spatial dimension. In this paper we give details of the defocusing optical concept by which scalar and vector information can be retrieved within large volumes. The optical model and computational procedures are presented with the specific purpose of mapping the number density, the size distribution, the associated local void fraction and the velocity of bubbles or particles in two-phase flows. Every particle or bubble is characterized in terms of size and of spatial coordinates, used to compute a true three-component velocity field by spatial three-dimensional cross-correlation. The spatial resolution and uncertainty limits are established through numerical simulations. The performance of the DDPIV technique is established in terms of number density and void fraction. Finally, the velocity evaluation methodology, using the spatial cross-correlation technique, is described and discussed in terms of velocity accuracy

Impressão lenticular: autostereoscopic prints for advertising

O objetivo deste projeto é demonstrar o resultado da interação da modelagem 3D com a tecnologia de impressão lenticular, e encontrar um caminho para sua aplicação prática no universo da publicidade. O projeto explora os exemplos históricos de arte imersiva e sua utilização diversa na prática, aborda os fatores que influenciam a percepção humana de profundidade e também analisa vários métodos usados para produzir impressões estereoscópicas, a própria tecnologia lenticular e técnicas de publicidade. Através do método de design surge uma solução criativa e o trabalho final é realizado na forma física de um poster de impressão lenticular, que é uma proposta da sua utilização como estratégia de comunicação.The objective of this project is to demonstrate the result of mixing 3D modeling with lenticular printing technology, and find a way for its practical application in the world of advertising. The project explores historical examples of immersive art and its diverse use in practice. It addresses the factors that influence human depth perception and also explores various methods used to produce stereoscopic prints, lenticular technology itself, and advertising techniques. Through the design method, a creative solution emerges and the final work is carried out in the physical form of a lenticular poster, which is a proposition of its use as a communication strategy

Computerised stereoscopic measurement of the human retina

The research described herein is an investigation into the problems of obtaining useful clinical measurements from stereo photographs of the human retina through automation of the stereometric procedure by digital stereo matching and image analysis techniques. Clinical research has indicated a correlation between physical changes to the optic disc topography (the region on the retina where the optic nerve enters the eye) and the advance of eye disease such as hypertension and glaucoma. Stereoscopic photography of the human retina (or fundus, as it is called) and the subsequent measurement of the topography of the optic disc is of great potential clinical value as an aid in observing the pathogenesis of such disease, and to this end, accurate measurements of the various parameters that characterise the changing shape of the optic disc topography must be provided. Following a survey of current clinical methods for stereoscopic measurement of the optic disc, fundus image data acquisition, stereo geometry, limitations of resolution and accuracy, and other relevant physical constraints related to fundus imaging are investigated. A survey of digital stereo matching algorithms is presented and their strengths and weaknesses are explored, specifically as they relate to the suitability of the algorithm for the fundus image data. The selection of an appropriate stereo matching algorithm is discussed, and its application to four test data sets is presented in detail. A mathematical model of two-dimensional image formation is developed together with its corresponding auto-correlation function. In the presense of additive noise, the model is used as a tool for exploring key problems with respect to the stereo matching of fundus images. Specifically, measures for predicting correlation matching error are developed and applied. Such measures are shown to be of use in applications where the results of image correlation cannot be independently verified, and meaningful quantitative error measures are required. The application of these theoretical tools to the fundus image data indicate a systematic way to measure, assess and control cross-correlation error. Conclusions drawn from this research point the way forward for stereo analysis of the optic disc and highlight a number of areas which will require further research. The development of a fully automated system for diagnostic evaluation of the optic disc topography is discussed in the light of the results obtained during this research

Photomicrography as an artistic medium

This thesis investigated the problems associated with artistically photographing patterns that exist within the microscopic world echoed on a larger scale throughout nature. Photographing these patterns at a microscopic level presented a number of difficulties not associated with photographing patterns through traditional photographic means. This thesis explored the problems associated with photographing subjects on a microscopic level, specifically the issues presented by lighting subjects. Experimental techniques with multiple light sources as well as light spectrum were explored. Also explored was the history of microscopy and popular processes for modern microscopy. Images were created utilizing either a compound microscope or stereomicroscope in conjunction with a digital single-lens reflex (SLR) camera and a microscopy lens attachment. Subjects for images consisted of a variety of live and dead coral specimen, algae, saliva, blood, marine vertebrates and invertebrates, and terrestrial insects. Recommendations for further studies of the microscopic world and patterns are also presented