Vladimir Saveljev
Konyang, Public Safety Research Center, Faculty Member
- Dr. Vladimir Saveljev is a researcher at Konyang University (Nonsan, Korea) with over 40 years of scientific research... moreDr. Vladimir Saveljev is a researcher at Konyang University (Nonsan, Korea) with over 40 years of scientific research experience. He holds a Ph.D. in electrical and computer engineering from the Siberian Branch of the Russian Academy of Sciences. He started his carrier at the Institute of Automation and Electrometry, Novosibirsk, Russia. Afterward, his research continues at the Korea Institute of Science and Technology, Hanyang University, Dongguk University (Seoul, Korea), and Myongji University (Gyeonggi, Korea). His positions were as a research scientist/consultant, a lecturer, and a research professor.
He has authored and co-authored over 150 academic papers. These include 4 book chapters, 95 articles on 3D displays, and 72 studies of the moiré effect. To illustrate, the publications by Dr. Saveljev are highly cited. For instance, several of his journal articles received over 100 citations.
His current research interests include but are not limited to applied optics (autostereoscopic 3D displays, image quality), physics (moiré effect, moiré minimization, nanoparticles), and mathematics (wavelet transform).edit
Research Interests:
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... more
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.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
The full-parallax multiview images of geometric structures are generated from the reference functions (voxel patterns). The computer-generated images of wireframe threedimensional objects are analyzed qualitatively in order to extract the... more
The full-parallax multiview images of geometric structures are generated from the reference functions (voxel patterns). The computer-generated images of wireframe threedimensional objects are analyzed qualitatively in order to extract the spatial information.
Research Interests:
The previously proposed reference functions for synthesis and analysis of multiview images in autostereoscopic 3D displays are applied to the analysis of grayscale and noised images of a wireframe object.
Research Interests:
Considering the previously proposed reference functions for multiview and integral images as scaling functions of a wavelet transform, the multiview wavelets are proposed.
Research Interests:
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... more
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
Research Interests:
Research Interests:
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... more
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 moiré.
Research Interests:
The moiré effect was observed in a multilayered three-dimensional (3D) structure with voxels at the points of a simple cubic lattice. Visual corridors result from the moiré effect. The frontal camera’s corridors appear at distinctive... more
The moiré effect was observed in a multilayered three-dimensional (3D) structure with voxels at the points of a simple cubic lattice. Visual corridors result from the moiré effect. The frontal camera’s corridors appear at distinctive angles with rational tangents. We analyzed the effects of distance, size, and thickness. We carried out computer simulation and physical experiments; both confirmed the distinctive angles of the moiré patterns for the three camera locations near the facet, edge, and vertex. The conditions for the moiré patterns to appear in the cubic lattice were formulated. The results can be used in crystallography and in minimization of the moiré effect in LED-based volumetric 3D displays.
Research Interests:
Research Interests:
In this paper, we present a moiré display based on the finite distance effect, which has two non‐coplanar layers installed at a non‐zero gap.
Research Interests:
ABSTRACT A two-dimensional light-emitting diode array is used to replace the viewing-zone-forming optics in-multiview full-parallax three-dimensional image display systems. Since the array is not working merely as the viewing-zone-forming... more
ABSTRACT A two-dimensional light-emitting diode array is used to replace the viewing-zone-forming optics in-multiview full-parallax three-dimensional image display systems. Since the array is not working merely as the viewing-zone-forming optics but also as the backlight panel for the liquid-crystal display (LCD) panel, it allows constructing three-dimensional imaging systems having the same structure as the current LCD display. The designed system displays images with good depth sense. (C) 2007 Society of Photo-Optical Instrumentation Engineers.
Research Interests:
Research Interests:
Research Interests:
Moire fringes appearing in multiview full-parallax dimensional imaging systems can be minimized by proper selection of the vertex angle of pixel cells. Pixel cells with arbitrary vertex angles are built by crossing a pair of discrete line... more
Moire fringes appearing in multiview full-parallax dimensional imaging systems can be minimized by proper selection of the vertex angle of pixel cells. Pixel cells with arbitrary vertex angles are built by crossing a pair of discrete line arrays with gradients +/- alpha. The discrete lines are form by the sides of pixels along the straight lines approximating the discrete lines. The gradient of the lines is defined as the ratio between pixel numbers in vertical and horizontal directions. This method allows creating rhomb approximating pixel cells with a desired shape.
Research Interests:
Research Interests: Dimensional and Moire
Theoretical and experimental investigations of moirés in three-dimensional displays are performed in the spec- tral domain. The method of investigation of spectra basing on summation is proposed. It gives the trajectories of spectral... more
Theoretical and experimental investigations of moirés in three-dimensional displays are performed in the spec- tral domain. The method of investigation of spectra basing on summation is proposed. It gives the trajectories of spectral lines. The equations of trajectories are found analytically and confirmed experimentally. The locus of the optimal angle on the trajectories is found. The phenomenological mechanism of switching branches is proposed. The geometric structure of trajectories is determined. The experimental and theoretical data are in good agreement. Index Terms—Computer displays, displays, moiré effect, moiré minimization, moiré spectra, optimal angle, 3D display.
Research Interests:
Research Interests:
Research Interests: Mechanical Engineering, Algorithms, Computer Graphics, Artificial Intelligence, Physics, and 12 moreMedicine, Image Reconstruction, Three Dimensional Imaging, Applied Optics, Information Storage and Retrieval, Optical physics, Image Enhancement, Three Dimensional, Reproducibility of Results, Sensitivity and Specificity, Electrical And Electronic Engineering, and imaging system
Research Interests: Mechanical Engineering, Algorithms, Optics, Binocular vision, Image Quality, and 10 moreThree Dimensional Imaging, Applied Optics, Computer User Interface Design, Optical physics, Image Enhancement, Microlens, Holographic Display, Electrical And Electronic Engineering, Optical Society of America, and imaging system
Research Interests:
Research Interests:
In this paper we consider couple of examples of engineering applications of projective transformations including the following: An observer region of a 3D display device An image region of a 3D display device A visual tool for safe... more
In this paper we consider couple of examples of engineering applications of projective transformations including the following: An observer region of a 3D display device An image region of a 3D display device A visual tool for safe driving (vehicle control, namely parking assistance) All three cases involve the central projection. It can be conveniently represented with using homogeneous coordinates.
Research Interests:
Basing on the theory for arbitrary oriented surfaces, we developed the theory of the moir\'e effect for cylindrical single-layer objects in the paraxial approximation. With using the dual grids, the moir\'e effect in the plane... more
Basing on the theory for arbitrary oriented surfaces, we developed the theory of the moir\'e effect for cylindrical single-layer objects in the paraxial approximation. With using the dual grids, the moir\'e effect in the plane gratings is simulated, as well as the near-axis moir\'e effect in cylinders including the chiral layouts. The results can be applied to the graphene layers, to single-walled nanotubes, and to cylinders in general.
The article presents the experimental measurements of the amplitude of the moir\'e patterns in a digital autostereoscopic barrier-type 3D display across a wide angular range with a small increment. The period and orientation of the... more
The article presents the experimental measurements of the amplitude of the moir\'e patterns in a digital autostereoscopic barrier-type 3D display across a wide angular range with a small increment. The period and orientation of the moir\'e patterns were also measured as functions of the angle. Simultaneous branches are observed and analyzed. The theoretical interpretation is also given. The results can help preventing or minimizing the moir\'e effect in displays.
The authors found equations for complex coordinates of spectral peaks and trajectories in the case of two superposed layers, each consisting of two orthogonal gratings. The number of geometric elements in spectra was found for four... more
The authors found equations for complex coordinates of spectral peaks and trajectories in the case of two superposed layers, each consisting of two orthogonal gratings. The number of geometric elements in spectra was found for four running parameters and different number of gratings by layers. The shape of trajectories was determined in the corresponding cases. The relationships between parameters were found which could help in reducing the intervals of parameters, in particular the relationship between the inverse aspect ratios. The numerical simulation and the physical experiment were in a good agreement with the theory. The proposed technique seems to be helpful in estimation of occurrence of moire patterns in visual displays which makes possible the minimization in the spectral domain without calculation of spectra.
A two dimensional quality function which counts both the number of mixed view images and disparity between images is derived based on the one dimension quality function which counts the number of mixed view images in multiview 3... more
A two dimensional quality function which counts both the number of mixed view images and disparity between images is derived based on the one dimension quality function which counts the number of mixed view images in multiview 3 dimensional imaging systems. This function predicts the quality of images with reasonable accuracy. This is proved experimentally.
Research Interests: Engineering and Geography
The moiré effect is an optical phenomenon which has a negative influence to the image quality; as such, this effect should be avoided or minimized in displays, especially in autostereoscoipic three-dimensional ones. The structure of the... more
The moiré effect is an optical phenomenon which has a negative influence to the image quality; as such, this effect should be avoided or minimized in displays, especially in autostereoscoipic three-dimensional ones. The structure of the multiview autostereoscoipic displays typically includes two parallel layers with an integer ratio between the cell sizes. In order to provide the minimization of the moiré effect at finite distances, we developed a theory and computer simulation tool which simulates the behavior of the visible moiré waves in a range of parameters (the displacement of an observer, the distance to the screen and the like). Previously, we have made simulation for the sinusoidal waves; however this was not enough to simulate all real-life situations. Recently, the theory was improved and the non-sinusoidal gratings are currently included as well. Correspondingly, the simulation tool is essentially updated. In simulation, parameters of the resulting moiré waves are measured semi-automatically. The advanced theory accompanied by renewed simulation tool ensures the minimization and make it convenient. The tool run in two modes, overview and detailed, and can be controlled in an interactive manner. The computer simulation and physical experiment confirm the theory. The typical normalized RMS deviation is 3 - 5%.
Research Interests:
We describe an optical phenomenon of unmovable moiré patterns in sliding (moving) grids and gratings. The phenomenon was observed visually in the planar straight movement of the black-and-white gratings with a period of several mm. This... more
We describe an optical phenomenon of unmovable moiré patterns in sliding (moving) grids and gratings. The phenomenon was observed visually in the planar straight movement of the black-and-white gratings with a period of several mm. This is a velocity-independent effect confirmed analytically and in a computer simulation based on the spatial averaging. We found the static directions of the moiré patterns in the regular grids, but our technique can be also applied to other objects. The orientation and period of the static moiré patterns are not obvious, especially in the presence of the distance effect. The phenomenon can be practically used in security applications.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
The wavelet analysis of the integral images can be used in extraction of the depth of the photographed/synthesized 3D objects. The result of the analysis, however, depends on the colour/texture of the object and thus can be ambiguous. In... more
The wavelet analysis of the integral images can be used in extraction of the depth of the photographed/synthesized 3D objects. The result of the analysis, however, depends on the colour/texture of the object and thus can be ambiguous. In this paper, we propose to normalize the image before processing in order to avoid such an ambiguity, and to extract the depth without regard to the colour/texture. The proposed technique is verified in multiple integral/plenoptic images and can be applied to multiview and light-field displays as well.
Research Interests:
Research Interests:
Research Interests:
The book describes not only 2D moiré patterns but also explores the moiré effect in other dimensions, such as 1D and 3D (volumetric moiré patterns). It explains the time-dependent moiré effect, including spectral trajectories. The book... more
The book describes not only 2D moiré patterns but also explores the moiré effect in other dimensions, such as 1D and 3D (volumetric moiré patterns). It explains the time-dependent moiré effect, including spectral trajectories. The book features various illustrations and examples. These will help the reader identify the moiré effect and distinguish it from other similar-looking effects. It will allow the reader to evaluate moiré patterns in particular circumstances, to establish control over the moiré effect, and to use it in modern technologies