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Related papers: Morphological variations to a ptychographic algori…

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Novel imaging techniques utilizing nondegenerate, correlated photon pairs sparked intense interest during the last couple of years among scientists of the quantum optics community and beyond. It is a key property of such "ghost imaging" or…

Applied Physics · Physics 2020-06-26 Andras Buzas , Elmar K. Wolff , Mihaly G. Benedict , Pal Ormos , Andras Der

This study explores the use of photometric techniques (shape-from-shading and uncalibrated photometric stereo) for upsampling the low-resolution depth map from an RGB-D sensor to the higher resolution of the companion RGB image. A…

Computer Vision and Pattern Recognition · Computer Science 2019-06-26 Bjoern Haefner , Songyou Peng , Alok Verma , Yvain Quéau , Daniel Cremers

Diffraction microtomography in coherent light is foreseen as a promising technique to image transparent living samples in three dimensions without staining. Contrary to conventional microscopy with incoherent light, which gives…

Optics · Physics 2009-11-13 Stanislas Vertu , Jean-Jacques Delaunay , Olivier Haeberle

Different studies in x-ray microscopy have arrived at conflicting conclusions about the dose efficiency of imaging modes involving the recording of intensity distributions in the near (Fresnel regime) or far (Fraunhofer regime) field…

Image and Video Processing · Electrical Eng. & Systems 2020-12-23 Ming Du , Doga Gursoy , Chris Jacobsen

Various imaging techniques have significantly enhanced our ability to visualize objects embedded within complex media such as biological tissues, fog, atmosphere, or various turbid media. Optical imaging, in particular, offers multiple…

Optics · Physics 2025-05-05 Mingwei He , Sujit K. Sahoo , Chengyuan Xiao , Cuong Dang

Phase-contrast and dark-field imaging are relatively new X-ray imaging modalities that provide additional information to conventional attenuation-based imaging. However, this new information comes at the price of a more complex acquisition…

A numerical solution to shape-from-shading under natural illumination is presented. It builds upon an augmented Lagrangian approach for solving a generic PDE-based shape-from-shading model which handles directional or spherical harmonic…

Computer Vision and Pattern Recognition · Computer Science 2017-12-05 Yvain Quéau , Jean Mélou , Fabien Castan , Daniel Cremers , Jean-Denis Durou

We demonstrate a new attosecond pulse reconstruction modality which uses an algorithm that is derived from ptychography. In contrast to other methods, energy and delay sampling are not correlated, and as a result, the number of electron…

Optics · Physics 2015-11-17 M. Lucchini , M. H. Brügmann , A. Ludwig , L. Gallmann , U. Keller , T. Feurer

For many applications, we need to use techniques to represent convex shapes and objects. In this work, we use level set method to represent shapes and find a necessary and sufficient condition on the level set function to guarantee the…

Numerical Analysis · Mathematics 2018-11-13 Shousheng Luo , Xue-cheng Tai

By taking into account the properties and limitations of the human visual system, images can be more efficiently compressed, colors more accurately reproduced, prints better rendered. To show all these advantages in this paper new adapted…

Computer Vision and Pattern Recognition · Computer Science 2015-03-13 Jaswinder Singh Dilawari , Ravinder Khanna

In this work, we propose a new segmentation algorithm for images containing convex objects present in multiple shapes with a high degree of overlap. The proposed algorithm is carried out in two steps, first we identify the visible contours,…

Computer Vision and Pattern Recognition · Computer Science 2017-11-08 Kumar Abhinav , Jaideep Singh Chauhan , Debasis Sarkar

Fourier ptychographic microscopy (FPM) is a computational imaging technique that overcomes the physical space-bandwidth product (SBP) limit of a conventional microscope by applying angular diversity illuminations. In the usual model of FPM,…

Optics · Physics 2019-03-05 An Pan , Chao Zuo , Yuege Xie , Yan Zhang , Ming Lei , Baoli Yao

An approach to diffraction tomography is investigated for two-dimensional image reconstruction of objects surrounded by an arbitrarily-shaped curve of sources and receivers. Based on the integral theorem of Helmholtz and Kirchhoff, the…

Mathematical Physics · Physics 2014-11-20 G. T. Clement

Birefringence, an inherent characteristic of optically anisotropic materials, is widely utilized in various imaging applications ranging from material characterizations to clinical diagnosis. Polarized light microscopy enables…

The square and rectangular shape of the pixels in the digital images for sensing and display purposes introduces several inaccuracies in the representation of digital images. The major disadvantage of square pixel shapes is the inability to…

Computer Vision and Pattern Recognition · Computer Science 2015-06-23 Sherin Sugathan , Reshma Scaria , Alex Pappachen James

Light sheet fluorescence microscopy is able to image large specimen with high resolution by imaging the sam- ples from multiple angles. Multi-view deconvolution can significantly improve the resolution and contrast of the images, but its…

Quantitative Methods · Quantitative Biology 2014-12-03 Stephan Preibisch , Fernando Amat , Evangelia Stamataki , Mihail Sarov , Robert H. Singer , Eugene Myers , Pavel Tomancak

Fourier ptychography (FP) is a recently proposed computational imaging technique for high space-bandwidth product imaging. In real setups such as endoscope and transmission electron microscope, the common sample motion largely degrades the…

Shape from Polarization (SfP) estimates surface normals using photos captured at different polarizer rotations. Fundamentally, the SfP model assumes that light is reflected either diffusely or specularly. However, this model is not valid…

Computer Vision and Pattern Recognition · Computer Science 2016-06-14 Vage Taamazyan , Achuta Kadambi , Ramesh Raskar

Spectroscopic ptychography is a powerful technique to determine the chemical composition of a sample with high spatial resolution. In spectro-ptychography, a sample is rastered through a focused x-ray beam with varying photon energy so that…

Image and Video Processing · Electrical Eng. & Systems 2020-07-21 Huibin Chang , Ziqin Rong , Pablo Enfedaque , Stefano Marchesini

This paper presents a microscopic imaging technique that uses variable-angle illumination to recover the complex polarimetric properties of a specimen at high resolution and over a large field-of-view. The approach extends Fourier…