Vladmir V. Saveljev

Viewing zones in three-dimensional imaging systems based on lenticular, parallax-barrier, and microlens-array plates

The viewing zone of autostereoscopic imaging systems that use lenticular, parallax-barrier, and microlens-array plates as the viewing-zone-forming optics is analyzed in order to verify the image-quality differences between different locations of the zone. The viewing zone consists of many subzones. The images seen at most of these subzones are composed of at least one image strip selected from the total number of different view images displayed. These different view images are not mixed but patched to form a complete image. This image patching deteriorates the quality of the image seen at different subzones. We attempt to quantify the quality of the image seen at these viewing subzones by taking the inverse of the number of different view images patched together at different subzones. Although the combined viewing zone can be extended to almost all of the front space of the imaging system, in reality it is limited mainly by the image quality.

A method of building pixel cells with an arbitrary vertex angle

Moire fringes appearing in contact-type three-dimensional imaging systems cause serious image quality deterioration. The fringes are inevitable because the systems require overlapping a viewing-zone-forming optical plate on a display panel. An analysis shows that the visual effects of the fringes can be minimized by finding a proper overlapping angle between the panel and the plate. This angle imposes that pixel cell in full-parallax imaging systems should have the shape of either rhombus or parallelogram with a specific vertex angle. The pixel cell with the shape of the rhombus or parallelogram is implemented by approximating the boundaries of each pixel cell by staircase lines drawn along sides of the pixel. The slopes of the lines are determined by the ratio of the pixel numbers in the vertical and horizontal directions. This method allows creating pixel cells with a desired vertex angle for minimizing the moire fringes, especially in full-parallax imaging systems.

Synthesizing 3D images based on voxels

Voxel is a basic picture element for composing 3D images. Since the generation of each voxel involves at least four pixels from four different view images for the case of full parallax 3D images, any voxel can be generated if the pixel pattern can be found. To find the pixel pattern, a set of voxels with known coordinated values are created by an optical geometry of the point light source array based 3D imaging system. This geometry provides that voxels aligned in planes parallel to the point light source array plane. The pixel pattern corresponding to each voxel is determined as the passage of seeing the point light sources related with the voxel, in the viewing zone. The resulting pixel patterns creates a good 3D image.

Characteristics of pixel arrangements in various rhombuses for full-parallax three-dimensional image generation

In full-parallax three-dimensional (3-D) imaging systems, the pixel cells often have the shape of a rhombus. Proper arrangement of pixels in these rhombic-shaped cells is important to maximize the quality of displayable 3-D images with a given display panel. The possible number of pixel arrangements in a rhombic cell with a definite dimension is found by considering the number of possible crossings between parallel line families forming the pixel cells, when the slopes of the lines are approximated by the ratio between the number of pixels in the vertical and horizontal directions. To make the rhombic cell have a uniquely defined pixel arrangement, its horizontal and vertical dimensions should be equal to the even multiple of the pixel dimension in their corresponding direction.

Pixel Patterns for Voxels in Contact-Type Three Dimensional Imaging Systems

A three dimensional image (3-D) is synthesized with the use of voxels with known coordinates. Each of these voxels has a corresponding pixel pattern in the display panel. The pattern is found in the optical geometry of the defined viewing zone in contact-type 3-D imaging systems based on a point light source array by assuming that each of the voxels can be seen at any place in the zone. This geometry provides that voxels are aligned in known planes parallel to the array plane. Since each of these voxels is made of rays from specific point light sources, which pass specific pixels in the display panel, the pixel pattern for each voxel is determined as that of the pixels that enable the sources to be seen in the viewing zone through them. The resulting pixel pattern creates a good 3-D image.

Pixel patterns for voxels in a contact-type three-dimensional imaging system for full-parallax image display

Incomplete voxels, which can be seen only at a part of the viewing zones cross section in the optical configuration of a full parallax multiview imaging system based on a two-dimensional point light source array, are identified. Their corresponding pixel patterns are found to maximize the space where the voxels can exist in the configuration and to increase the voxel resolution of the displayable three-dimensional images. Furthermore, the pixel patterns for the rhomb-shaped pixel cells are also defined, and some problems related to voxel-based image synthesis are discussed.

Perceived images in IP and other multiview 3D imaging methods

The methods of presenting multiview images, such as IP, the Multiview, Multiple Imaging and Focused light array are reviewed and their image forming principles were compared. These methods have their own ways of presenting multiview images but the images projected to viewers eyes are mostly synthesized by the small part of each view image in the different view images presented to the viewers. This is a common property for all those methods.

3‐D Image Display on Handphone

A method of processing a stereo image pair in a cellular phone is described to minimize moire. This method includes the processes of 1) shifting every two rows of each image in the image pair a pixel to the right from its immediately above image rows, 2) combining both images of the pair by alternately arranging each column of each image of the pair, 3) elongating the combined image vertically to double its height, and 4) grouping two rows from top of the elongated images and then shifting every group a pixel left from its immediately below group. This way enables to display stereoscopic images without moire.

Full parallax images with a diamond shape pixel cell

Characteristics and two building methods of diamond shaped pixel cell are introduced. It can provide wider horizontal direction size of viewing zone compared with its corresponding square or rectangular pixel cell and reduce the pseudoscopic effect. The two building methods are named as integer and non-integer depending on the number of different view pixels involved with the pixel cell. The full parallax images generated by these two methods shows that the integer method provides better image quality than the non-integer.

Synthesizing 3-D Images with Voxels

3-D images provide viewers with more accurate and realistic information than 2-D images. They also bring immersive feeling to the viewers with depth sense, on the other hand, often causing dizziness and serious eye fatigue. The main demands of 3-D images occur in themovies, broadcasting, medical applications, advertisement, telepresence, education and entertainment, and so on. Generally 3-D images adopt “voxel” representation, which is analogous to the concept of “pixel” in 2-D images. The voxels, basic elements of 3-D images, are used to describe virtual points. Any desired 3-D image can be displayed by synthesizing it with voxels of pre-defined coordinate values because 3-D images are formed by voxels. Voxels can be visible if a group of pixels in the display panel, which is responsible for making each voxel visible at the viewing zone, is defined because voxels are virtual points in a pre-defined space. The viewing zone is a spatial location where viewers can see entire images displayed on the screen. The multi-view (MV) [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14] and IP (Integral Photography) [15, 16, 17, 18, 19, 20, 21, 22, 23] are the typical methods of displaying a full parallax 3-D image on a flat panel display. As autostereoscopic image displays these methods have been a matter of great concern since 1990. MV and IP have the same optical structure composed of a viewing zone forming optics and a display panel located at the focal plane