scispace - formally typeset
Search or ask a question

Does the log-polar transform keep the phase value of OAM? 


Best insight from top research papers

The log-polar transform is widely used in image recognition, particularly in the recognition of face images. It is known for its ability to detect scaling and rotation in a 2D space . However, it is limited to 2D environments and does not detect affine transformations or posture in a 3D environment . The log-polar transform has been implemented in different ways for feature matching methods, such as image registration and template matching . It has also been used to create local image features that are invariant to orientation and scale variations, which can be used for pose estimation of 3D objects . The log-polar transform does not specifically preserve the phase value of OAM, as it primarily focuses on scaling, rotation, and affine transformations .

Answers from top 4 papers

More filters
Papers (4)Insight
The provided paper does not mention anything about the phase value of OAM in relation to the log-polar transform.
The paper does not mention anything about the log-polar transform keeping the phase value of OAM.
The provided paper does not mention anything about the phase value of OAM.
Proceedings ArticleDOI
T. Nakata, Yue Bao 
01 Dec 2008
The provided paper does not mention anything about the phase value of OAM.

Related Questions

Research on OAM propagation analysis with infinitesimal dipoles?5 answersResearch on OAM propagation analysis with infinitesimal dipoles has been extensively explored in recent studies. Various models, such as the infinitesimal dipole method customized for OAM EM fields, circular arrays of infinitesimal dipoles for OAM wave sources and receivers, and circular arrays of half-wavelength dipoles for OAM wave generation and reception, have been utilized. These studies have investigated the impact of different factors on OAM wave propagation, including the influence of the ground plane on OAM communication, the effects of conducting plates on OAM-based wireless communication, and the modeling of radiation patterns of aperiodic arrays using an infinitesimal dipole model. The findings contribute to optimizing OAM-based communication systems for realistic environments.
Do the log-normal distribution can be used as a image turbulence?5 answersThe log-normal distribution is commonly used to model turbulence in various contexts. It has been argued that a log-skew-normal (LSN) distribution may be more appropriate for turbulence generated by multiple changing sources. However, empirical evidence shows that the dissipation of kinetic energy in the global ocean follows a nearly log-normal distribution, even at large horizontal scales. Experimental studies on wind tunnel turbulence also support the log-normality of cascading processes. On the other hand, the log-normal distribution does not generally apply to the sum of independent random variables. Additionally, the log-stable distribution has been found to accurately describe the probability density function of velocity derivatives in a turbulent boundary layer. Therefore, while the log-normal distribution is commonly used in turbulence analysis, alternative distributions may be more appropriate in certain cases.
How the OAM-MIMO perform on free space optical communication with IM/DD?5 answersOAM-MIMO performs well in free space optical communication with intensity modulation and direct detection (IM/DD) systems. The use of OAM modes in MIMO coherent FSO communication systems can minimize the impact of atmospheric turbulence (AT) distortions and improve system performance. Additionally, the incorporation of OAM-MIMO with spatial mode multiplexing (SMM) and mode diversity schemes can enhance transmission capacity, mitigate multipath fading, and reduce atmospheric turbulence distortions. Furthermore, the use of OAM mode-group multiplexing (OAM-MGM) with transmitter mode diversity can increase system reliability under turbulence, reducing system interruption probability. The non-orthogonal OAM-MIMO system with fractional OAM modes also shows better performance compared to traditional MIMO systems, as it integrates more data streams into signals with larger power, resulting in lower bit error rates.
Download and unzip the GPhyLab01_PhaserJSIntroExample_210902.zip3 answersThe abstracts provided do not contain any information related to downloading and unzipping a specific file named "GPhyLab01_PhaserJSIntroExample_210902.zip."
How can incoherent light be used to generate OAM?5 answersIncoherent light can be used to generate orbital angular momentum (OAM) beams by miniaturizing spiral phase plates and integrating them with structural color filters. These optical elements act as building blocks that encode both color and OAM information in the form of colorful optical vortices. By achieving spatio-temporal coherence using only an incoherent white light source, pairs of transparent substrates that contain matching positions of these vortices can form a reciprocal optical lock and key system. Additionally, a photonic crystal-based OAM generator has been proposed, which allows for high-accuracy beam alignment and scalability of topological charges. Another approach involves using a standard silica optical fiber, where a properly tilted input laser beam is injected into the fiber cladding to break the axial symmetry and generate OAM beams. These methods have potential applications in various fields such as optical communication, super-resolution imaging, and high-dimensional quantum computing.
How can we design metasurfaces that generate wideband OAM vortex beams?3 answersMetasurfaces that generate wideband OAM vortex beams can be designed using various approaches. One approach is to use active metasurfaces in reflection manner, which can generate reconfigurable OAM vortex beams with high purity in a specific frequency range. Another approach is to design flat Pancharatnam-Berry (PB) metasurfaces with low RCS, which can generate scattered vortex waves with orbital angular momentum (OAM). Additionally, all-dielectric geometric metasurfaces can be used to generate perfect vortex beams (PVBs) with specific topological charges (TCs) based on tailored spiral phase distributions. Furthermore, an all-graphene geometric metasurface operating in the terahertz (THz) band can generate multidimensional vortices by introducing the superposition of two helical phases with the same topological charge within orthogonal circularly polarized (CP) channels. These design approaches provide different methods for generating wideband OAM vortex beams with various applications in optical communication and manipulation.

See what other people are reading

How to obtain fracture distribution from microseismic data and reservoir simulation?
5 answers
How riding fatigue influence risky riding behaviour among p-hailing riders?
5 answers
How the AI research landscape?
5 answers
How does line detection work in computer vision?
5 answers
How does line detection work in computer vision?
5 answers
How much c15 is in chicken?
4 answers
Does text dictation help elementary students?
5 answers
How is SSD used in currency classification?
4 answers
How does the accuracy of Easy OCR depend on factors such as font size, type, and orientation?
5 answers
The accuracy of Easy OCR is influenced by factors like font size, type, and orientation. Different techniques have been proposed to address these factors. Font style recognition based on distance profile features can reduce computational complexity and improve accuracy. Text orientation estimation using edge detection and image rotation can enhance OCR performance. Combining diverse recognition systems through iVector-based features can improve OCR accuracy by considering various factors like writing style and material. Additionally, determining the correct document orientation based on confidence factors associated with character images can optimize OCR results. These approaches collectively demonstrate how font size, type, and orientation impact Easy OCR accuracy and highlight the importance of addressing these factors for improved performance.
What are the mathematical formulas used to calculate the center and radius of a circle?
4 answers
To calculate the center and radius of a circle, various mathematical formulas and algorithms are employed. One approach involves selecting an initial point within the circle and tracking pixels horizontally and vertically to determine the circle's border pixels, enabling the calculation of the center and radius. Another method utilizes a fuzzy searching algorithm based on distance and orientation parameters to accurately detect the center of circular or polygonal shapes, reducing computational complexity significantly. Additionally, a non-HT circle detection algorithm measures the energy of pixels based on gradient vectors to identify potential circle centers and computes the feature circle radius for accurate radius detection. Furthermore, a method involving statistical analysis of row and column coordinates arrays is used to compute the circle's center and radius with good accuracy and noise suppression capabilities.
What are the different formulas used to find the center and radius of a circle in analytic geometry?
4 answers
Various formulas are employed in analytic geometry to determine the center and radius of a circle. One method involves applying the least-squares approach to data points along a pattern border to estimate the circle's center and radius. Another technique introduces a new least-squares method that provides analytical expressions for the central point coordinates and radius of a circle, along with variances and covariances, which is useful in interferometry and radiometry applications. Additionally, a non-HT circle detection algorithm utilizes the feature circle energy (FCE) distribution map to identify potential circle centers and the feature circle radius (FCR) to detect the circle's radius accurately, even in the presence of noise in images.