This article examines the problem of obtaining three-dimensional images of an object using digital holography. Several methods based on holographic interferometry exist: the offset source method, the immersion method, the dual-wavelength method, and the use of a low-coherence illumination source. Each of the methods discussed has its own advantages and disadvantages. In most cases, quantitative information about the relief parameters is required. However, the poor quality of topographic fringes and the problem of determining the sign during relief determination cause significant difficulties in volume determination. These problems can be overcome by using a simple method of determining the volume using two stereo images reconstructed from holograms and subsequent refinement using one of the methods for obtaining holographic topographic maps. This paper demonstrates a method for determining a three-dimensional image using two stereo images of an object reconstructed from digital holograms. long exposure and development time, which is usually done separately from the optical setup. In the case of holographic interferometry systems, it is necessary to provide for mounting the hologram back into the optical setup with sufficiently high accuracy. Therefore, digital holography methods have been developed to record holograms on photomatrices with limited resolution. These methods are based on the use of optical schemes at small angles (less than 5 degrees) between interfering beams. Recently, sensors with a single element size of 1.33 µm and 0.56 µm have appeared. This resolution makes it possible to return to registration schemes with angles between interfering beams of 30-60 degrees. This allows us to hope for the revival of holographic methods and methods of holographic interferometry at the modern level without the use of intermediate recording media.
Keywords: obtaining holograms and reconstructing images from them, digital holography, spatial resolution of holograms, stereo images, reconstruction of volumetric images
A method for recording holograms using digital cameras with high spatial resolution is considered. To register holograms obtained in optical setups with an inclined reference beam, a high resolution of registration systems is required. To do this, it is necessary to use media with a resolution of 2000-4000 lines per mm. The use of photographic plates requires a fairly long exposure and development time, which is usually done separately from the optical setup. In the case of holographic interferometry systems, it is necessary to provide for mounting the hologram back into the optical setup with sufficiently high accuracy. Therefore, digital holography methods have been developed to record holograms on photomatrices with limited resolution. These methods are based on the use of optical schemes at small angles (less than 5 degrees) between interfering beams. Recently, sensors with a single element size of 1.33 µm and 0.56 µm have appeared. This resolution makes it possible to return to registration schemes with angles between interfering beams of 30-60 degrees. This allows us to hope for the revival of holographic methods and methods of holographic interferometry at the modern level without the use of intermediate recording media.
Keywords: digital holography, high spatial resolution photo matrix, tilted reference beam holography, Fourier transform
A method for recording holograms using digital cameras with high spatial resolution is considered. To register holograms obtained in optical setups with an inclined reference beam, a high resolution of registration systems is required. To do this, it is necessary to use media with a resolution of 2000-4000 lines per mm. The use of photographic plates requires a fairly long exposure and development time, which is usually done separately from the optical setup. In the case of holographic interferometry systems, it is necessary to provide for mounting the hologram back into the optical setup with sufficiently high accuracy. Therefore, digital holography methods have been developed to record holograms on photomatrices with limited resolution. These methods are based on the use of optical schemes at small angles (less than 5 degrees) between interfering beams. Recently, sensors with a single element size of 1.33 µm and 0.56 µm have appeared. This resolution makes it possible to return to registration schemes with angles between interfering beams of 30-60 degrees. This allows us to hope for the revival of holographic methods and methods of holographic interferometry at the modern level without the use of intermediate recording media.
Keywords: holography, holographic interferometry, photomatrices with high spatial resolution, holography with an inclined reference beam, digital holography, Fourier transform
The article discusses the method of automatic elimination of nonlinearity in the registration of intensity in projection systems. Errors in the intensity recording affect the accuracy of phase measurement systems based on structured illumination of objects. Gamma-correction hardware cannot completely eliminate such distortions, since the type of inverse relationship may be a more complex function. The method is based on the projection of the ideal wedge and automatic determination of the intensity levels required for recording
Keywords: optical measurement systems, structured lighting, profile detection, intensity, nonlinear distortion, digital image processing
The article considers a method of increasing the resolution of images in holographic systems based on subpixel shift algorithms. Methods of solving systems of equations of large dimension by reducing to block form are considered. The simplest solution is obtained when a set of matrices with an increased resolution is formed from a set of matrices with a shift in one direction, and then the resultant matrix is formed from the resulting set.
Keywords: super resolution, subpixel shift, holography, solution of systems of equations, holographic interferometry, aperture
The model of mobile system of diagnostics and automatic regulation of multiphase environments flow regimes is considered. The analysis of existing methods for determining the thermal parameters of a mixture of several gases and liquids in the presence of particulate matter in the stream showed the relevance of the small size mobile systems, in which the measurement is made with modern sensors for pressure, temperature, gas content. Control signals state multiphase flow formed in the controller based on the values of the complexes Kutateladze - Sorokin, Baker. Specific designer elements of diagnostics and regulation system development of multiphase environments flow regimes is offered. The directions for further research in relation to specific multiphase systems are planned.
Keywords: mobile system, multiphase flow, diagnostics, regulation
The paper introduce modern information about localization of function of human cerebral cortex from the viewpoint of brain’s structure.
Keywords: brain, cerebral cortex, contex cerebi, neocortex, cytoarchitectonics, functional map of cere-bral cortex, localization of function of cerebral cortex, sensomotor centers