Персона: Родин, Владислав Геннадьевич
Email Address
Birth Date
Результаты поиска
Virtual camera-based analysis of photosensor characterization methods
DMD-based optical pattern recognition using holograms generated with the Hartley transform
Methods of diffractive optical element generation for rapid, high-quality 3D image formation of objects divided into a set of plane layers
An optical-digital method of noise suppression in digital holography
Оптические системы с синтезом импульсного отклика для обработки информации в пространственно-некогерентном и немонохроматическом излучении
Optical encryption of images in spatially incoherent light using DMD modulator
© OSA 2019 © 2019 The Author(s)Scheme of real time optical encryption using DMD modulator is described. Experimental results of optical encryption of images in spatially incoherent light are demonstrated.
Error diffusion hologram binarization for DMD applications
© 2021 SPIE.Digital micromirror device (DMD) allows very fast binary light modulation. For digital hologram displaying using DMD, binarization should be applied. In this work, 12 error diffusion and 8 dot diffusion binarization algorithms were considered. All methods were used in both iterative and non-iterative forms. Quality of reconstructed images from binarized holograms was compared. Optically registered digital holograms and synthesized holograms of binary and grayscale images were used. Among the error diffusion methods, Stucky's and Atkinson's standard error diffusion methods and dot diffusion methods provide the highest quality of reconstruction. The effect of the pixel bypass matrix on the quality of reconstructed images was also evaluated. As bypass matrices, standard variants (for example, direct and reverse sequential bypass of pixels on rows or columns, a matrix with a line-by-line alternating direction of bypass of pixels, a spinning and swirling spiral matrices), and more complex types (for example, used in the Knuth dot diffusion method) were used. Non-iterative error diffusion with use of several specialized bypass matrices improves the quality up to 7%. Iterative realization of the error diffusion allows to increase quality to 15%.
Influence of Spatial Losses of the Signal Detected by a Single-Pixel Detector on the Quality of Object Image Reconstruction
© 2021, Springer Science+Business Media, LLC, part of Springer Nature.The reconstruction methods, which are based on compressed sensing (CS), make it possible to record and reconstruct information basing on its sparse or compressed representation. In this work, we study resistance of CS-based single-pixel imaging to partial loss of the intensity of the recorded radiation from an object with a limited area of the detector. The problem was solved experimentally by implementing the so-called single-pixel camera, as well as detecting optical radiation from the object and reconstructing its image with the use of CS methods. The method resistance to spatial radiation losses is estimated as a function of the size and shape of the detector aperture. The quality of image reconstruction depending on the two following factors is assessed: the fraction of the intensity of the detected radiation and the quantity of single-pixel detections. The results can ensure significantly wider application of the method to reconstruct data, both detected in dynamic and scattering media (including the introduction of various apertures and Fourier filtering) and in the case of significant spatial radiation losses.
A method for measuring digital camera noise by automatic segmentation of a striped target
Currently, cameras are widely used in scientific, industrial and amateur tasks. Thus, one needs to be able to quickly evaluate characteristics and capabilities of a particular camera. A method for measuring noise components of the camera photosensor is proposed. It allows one to estimate shot noise, dark temporal noise, photo response non-uniformity and dark signal non-uniformity. For noise measurement, just two images of the same scene need to be registered. The scene consists of several stripes (quasihomogeneous regions). Then the images are processed by automatic signal segmentation. The performance and accuracy of the proposed method are higher than or equal to other fast methods. The experimental results obtained are similar to those derived using a time-consuming standard method within a measurement error.
Interpolation-Filtering Method for Image Improvement in Digital Holography
Digital holography is actively used for the characterization of objects and 3D-scenes, tracking changes in medium parameters, 3D shape reconstruction, detection of micro-object positions, etc. To obtain high-quality images of objects, it is often necessary to register a set of holograms or to select a noise suppression method for specific experimental conditions. In this paper, we propose a method to improve filtering in digital holography. The method requires a single hologram only. It utilizes interpolation upscaling of the reconstructed image size, filtering (e.g., median, BM3D, or NLM), and interpolation to the original image size. The method is validated on computer-generated and experimentally registered digital holograms. Interpolation methods coefficients and filter parameters were analyzed. The quality is improved in comparison with digital image filtering up to 1.4 times in speckle contrast on the registered holograms and up to 17% and 29% in SSIM and NSTD values on the computer-generated holograms. The proposed method is convenient in practice since its realization requires small changes of standard filters, improving the quality of the reconstructed image.