Cross-talk reduction by correcting the subpixel position in a multiview autostereoscopic three-dimensional display based on a lenticular sheet

Compensation of lens manufacturing errors and inhomogeneities by filtering view images in three-dimensional lenticular displays

For a multiview autostereoscopic three-dimensional display based on the lenticular lens, the manufacturing errors and inhomogeneities of the lenticular sheet can deteriorate the view image quality. A calibration method is proposed by filtering the pixel mapping of all view images. Each view is first sequentially turned on to show a white test image, and the intensity distribution of every view will be analyzed. Then individual filter functions are derived and applied to the corresponding view images to correct the subpixel value. Experimental results show that the proposed method can solve view image loss and significantly improve the quality of stereoscopic images.

High-speed and robust infrared-guiding multiuser eye localization system for autostereoscopic display

In order to localize the viewers' eyes, a high-speed and robust infrared-guiding multiuser eye localization system was fabricated in this paper for a binocular autostereoscopic display, which can project a pair of parallax images to corresponding eyes. The system is composed of a low-resolution thermal infrared camera, a pair of high-resolution left and right visible spectral cameras, and an industrial computer. The infrared camera and the left visible spectral camera, and the left and right visible spectral camera, can both form the binocular vision system. The thermal infrared camera can capture the thermography images. The left and right visible spectral cameras can capture the left and right visible spectral images, respectively. Owing to the temperature difference between the face and background, the features of the face in thermography images are prominent. We use the YOLO-V3 neural network to detect the viewers' faces in thermography images. Owing to the different features of the pseudo and real faces in the infrared spectral, in the thermography images, the pseudo-faces can be easily eliminated. According to the positions and sizes of potential bounding boxes of the detected faces in the thermography images, the industrial computer can be guided to determine the left candidate regions in the left visible spectral image. Then, the industrial computer can determine the right candidate regions in the right visible spectral image. In the left candidate regions, the industrial computer detects the faces and localize the eyes by using the SeetaFace algorithm. The template matching is performed between the left and right candidate regions to calculate the accurate distance between the viewer and the system. The average detection time of the proposed method is about 3-8 ms. Compared with traditional methods, the localization time is improved by 86.7%-90.1%. Further, the proposed method is hardly influenced by the pseudo-faces and the strong ambient light.

3D Display Calibration by Visual Pattern Analysis

Nearly all 3D displays need calibration for correct rendering. More often than not, the optical elements in a 3D display are misaligned from the designed parameter setting. As a result, 3D magic does not perform well as intended. The observed images tend to get distorted. In this paper, we propose a novel display calibration method to fix the situation. In our method, a pattern image is displayed on the panel and a camera takes its pictures twice at different positions. Then, based on a quantitative model, we extract all display parameters (i.e., pitch, slanted angle, gap or thickness, and offset) from the observed patterns in the captured images. For high accuracy and robustness, our method analyzes the patterns mostly in the frequency domain. We conduct two types of experiments for validation; one with optical simulation for quantitative results and the other with real-life displays for qualitative assessment. Experimental results demonstrate that our method is quite accurate, about a half order of magnitude higher than prior work; is efficient, spending less than 2s for computation; and is robust to noise, working well in the SNR regime as low as 6dB.

Three-dimensional display optimization with measurable energy model

3D displays have been developed to provide users with a realistic 3D experience. Although various studies have endeavored to establish design principles for 3D displays, a generalized optimized model does not exist in the literature thus far. These circumstances have led to the manufacture of independently qualified 3D products, but expanding these applications remains a challenge. In this paper, we suggest a measurement model and an optimization method for optimized 3D display design. The proposed optimization can be applied to rotatable 3D displays and various pixel structures. Our experimental results based on manufactured displays and simulations confirm the proposed theory of optimization model.

Improving the performance of an electrowetting lenticular lens array by using a thin polycarbonate chamber

In this paper, we used a thin polycarbonate (PC) chamber to improve the performance of an electrowetting lenticular lens array. The polycarbonate chamber changed the radius of curvature (ROC) of the oil acting as a lens, which increased the dioptric power of the liquid lens to 1666.7D. The increase in dioptric power required a reduction in the distance between the optical center of the lens and the display pixels under the chamber, which was accomplished by reducing the thickness of the chamber. The optimal thickness of the chamber was determined to be 0.5mm. Using this thin PC chamber, transmittance and viewing angle were measured and compared with an electrowetting lenticular lens with a conventional 1mm poly methyl methacrylate (PMMA) chamber was done. Crosstalk which degrades clear 3D images, is an inevitable factor in lenticular lens type multi-view systems. With the 0.5mm PC chamber, the viewing zone was expanded and the ratio of the crosstalk area was reduced, which resulted in a clear 3D image. The new method of depositing the electrode layer also ensured the uniform operation of the liquid lens array.

Aberration analyses for improving the frontal projection three-dimensional display

The crosstalk severely affects the viewing experience for the auto-stereoscopic 3D displays based on frontal projection lenticular sheet. To suppress unclear stereo vision and ghosts are observed in marginal viewing zones(MVZs), aberration of the lenticular sheet combining with the frontal projector is analyzed and designed. Theoretical and experimental results show that increasing radius of curvature (ROC) or decreasing aperture of the lenticular sheet can suppress the aberration and reduce the crosstalk. A projector array with 20 micro-projectors is used to frontally project 20 parallax images one lenticular sheet with the ROC of 10 mm and the size of 1.9 m × 1.2 m. The 3D image with the high quality is experimentally demonstrated in both the mid-viewing zone and MVZs in the optimal viewing plane. The 3D clear depth of 1.2m can be perceived. To provide an excellent 3D image and enlarge the field of view at the same time, a novel structure of lenticular sheet is presented to reduce aberration, and the crosstalk is well suppressed.

Optically anisotropic microlens array film directly formed on a single substrate

An optically anisotropic microlens array film directly formed on a single substrate is demonstrated. UV curable diacrylate monomers are coated as a film on the substrate. Under the action of fringing field, not only the film surface is flattened by the generated dielectric force but also the monomers are reoriented to form a gradient refractive index (GRIN) distribution in the film. Via UV exposure, the GRIN distribution is fixed and the polymeric film behaves as a microlens array. The fabrication process is simple and the film offers a switchable focus through controlling the polarization direction of the incident light. Integrating with a 90° twisted-nematic liquid crystal cell, our polymeric microlens array film shows great potential for switchable 2D/3D autostereoscopic displays.

Dichoptic Viewing Methods for Binocular Rivalry Research: Prospects for Large-Scale Clinical and Genetic Studies

Binocular rivalry (BR) is an intriguing phenomenon that occurs when two different images are presented, one to each eye, resulting in alternation orrivalrybetween the percepts. The phenomenon has been studied for nearly 200 years, with renewed and intensive investigation over recent decades. Therateof perceptual switching has long been known to vary widely between individuals but to be relatively stable within individuals. A recent twin study demonstrated that individual variation in BR rate is under substantial genetic control, a finding that also represented the first report, using a large study, of genetic contribution for any post-retinal visual processing phenomenon. The twin study had been prompted by earlier work showing BR rate was slow in the heritable psychiatric condition, bipolar disorder (BD). Together, these studies suggested that slow BR may represent an endophenotype for BD, and heralded the advent of modern clinical and genetic studies of rivalry. This new focus has coincided with rapid advances in 3D display technology, but despite such progress, specific development of technology for rivalry research has been lacking. This review therefore compares different display methods for BR research across several factors, including viewing parameters, image quality, equipment cost, compatibility with other investigative methods, subject group, and sample size, with a focus on requirements specific to large-scale clinical and genetic studies. It is intended to be a resource for investigators new to BR research, such as clinicians and geneticists, and to stimulate the development of 3D display technology for advancing interdisciplinary studies of rivalry.

Stereogram implemented with a holographic image splitter

A special holographic optical element (HOE) which is used as an image splitter is developed to generate a stereogram on a 2.2-in. liquid crystal display panel. The special designed holographic optical element can be attached on the conventional panel directly to replace the traditional image splitter in a stereoscopic display panel. Experimental results show that two images corresponding to slightly different viewing angles displayed on a panel can be separated effectively and can be delivered to the right eye and left eye of an observer individually. The diffraction efficiency for individual right and left image in this developed holographic optical element is about 43%, and the contrast ratio of the diffracted images induced by cross talk is larger than 60%. Theoretical analyses show the proposed technique generates good contrast ratio and brightness performance for stereogram application.