English
Related papers

Related papers: Variational Uncalibrated Photometric Stereo under …

200 papers

This paper presents a process for estimating the spatially varying surface reflectance of complex scenes observed under natural illumination. In contrast to previous methods, our process is not limited to scenes viewed under controlled…

Computer Vision and Pattern Recognition · Computer Science 2022-03-01 Alen Joy , Charalambos Poullis

Recovering the 3D geometry of a purely texture-less object with generally unknown surface reflectance (e.g. non-Lambertian) is regarded as a challenging task in multi-view reconstruction. The major obstacle revolves around establishing…

Computer Vision and Pattern Recognition · Computer Science 2021-05-26 Ziang Cheng , Hongdong Li , Yuta Asano , Yinqiang Zheng , Imari Sato

We propose a novel framework to automatically learn to aggregate and transform photometric measurements from multiple unstructured views into spatially distinctive and view-invariant low-level features, which are subsequently fed to a…

Computer Vision and Pattern Recognition · Computer Science 2024-12-12 Xiang Feng , Kaizhang Kang , Fan Pei , Huakeng Ding , Jinjiang You , Ping Tan , Kun Zhou , Hongzhi Wu

In this paper, we propose a novel white balance adjustment, called "spatially varying white balancing," for single, mixed, and non-uniform illuminants. By using n diagonal matrices along with a weight, the proposed method can reduce…

Computer Vision and Pattern Recognition · Computer Science 2021-09-06 Teruaki Akazawa , Yuma Kinoshita , Hitoshi Kiya

There is widespread interest in estimating the fluorescence properties of natural materials in an image. However, the separation between reflected and fluoresced components is difficult, because it is impossible to distinguish reflected and…

Computer Vision and Pattern Recognition · Computer Science 2016-05-16 Henryk Blasinski , Joyce Farrell , Brian Wandell

Spatial light modulators enable arbitrary control of the intensity of optical light fields and facilitate a variety of applications in biology, astronomy and atomic, molecular and optical physics. For coherent light fields, holography,…

The increased sensitivity of future radio telescopes will result in requirements for higher dynamic range within the image as well as better resolution and immunity to interference. In this paper we propose a new matrix formulation of the…

Astrophysics · Physics 2014-11-18 Chen Ben-David , Amir Leshem

We propose and demonstrate theoretically a method to achieve and design optical nonlinear responses through a light-mediated spatial hybridization of different standard nonlinearities. The mechanism is based on the fact that optical…

Optics · Physics 2008-04-24 Alessandro Ciattoni , Eugenio Del Re , Carlo Rizza , Andrea Marini

In this paper, we present a new mathematical foundation for image-based lighting. Using a simple manipulation of the local coordinate system, we derive a closed-form solution to the light integral equation under distant environment…

Computer Vision and Pattern Recognition · Computer Science 2017-05-16 Mais Alnasser , Hassan Foroosh

The common approach to radial distortion is by the means of polynomial approximation, which introduces distortion-specific parameters into the camera model and requires estimation of these distortion parameters. The task of estimating…

Computer Vision and Pattern Recognition · Computer Science 2007-05-23 Lili Ma , YangQuan Chen , Kevin L. Moore

Existing score-based methods for inverse problems often resort to approximate minimization of the KL divergence between the inversion distribution and the Bayesian posterior. Such an approximation leads to severe mode collapse and…

Computer Vision and Pattern Recognition · Computer Science 2026-05-26 Weimin Bai , Yuxuan Gu , Yifei Wang , Weijian Luo , He Sun

We present a novel convolutional neural network architecture for photometric stereo (Woodham, 1980), a problem of recovering 3D object surface normals from multiple images observed under varying illuminations. Despite its long history in…

Computer Vision and Pattern Recognition · Computer Science 2018-05-30 Tatsunori Taniai , Takanori Maehara

Geometry reconstruction of textureless, non-Lambertian objects under unknown natural illumination (i.e., in the wild) remains challenging as correspondences cannot be established and the reflectance cannot be expressed in simple analytical…

Computer Vision and Pattern Recognition · Computer Science 2023-10-27 Kohei Yamashita , Shohei Nobuhara , Ko Nishino

This paper introduces single-image geometric and appearance reconstruction from water reflection photography, i.e., images capturing direct and water-reflected real-world scenes. Water reflection offers an additional viewpoint to the direct…

Computer Vision and Pattern Recognition · Computer Science 2020-01-08 Ryo Kawahara , Meng-Yu Jennifer Kuo , Shohei Nobuhara , Ko Nishino

Solids with spatially varying photonic structure offer gaps to light of a wider range of frequencies than do simple photonic systems. We solve numerically the field distribution in a solid cholesteric with a linearly varying inverse pitch…

Soft Condensed Matter · Physics 2015-06-24 S. Kutter , M. Warner

This Letter presents a novel structured light system model that effectively considers local lens distortion by pixel-wise rational functions. We leverage the stereo method for initial calibration and then estimate the rational model for…

Optics · Physics 2023-05-15 Raúl Vargas , Lenny A. Romero , Song Zhang , Andres G. Marrugo

A lighting-based multispectral imaging system using an RGB camera and a projector is one of the most practical and low-cost systems to acquire multispectral observations for estimating the scene's spectral reflectance information. However,…

Image and Video Processing · Electrical Eng. & Systems 2020-12-21 Hironori Hidaka , Yusuke Monno , Masatoshi Okutomi

Phase is a fundamental resource for optical imaging but cannot be directly observed with intensity measurements. The existing methods to quantify a phase distribution rely on complex devices and structures. Here we experimentally…

Optics · Physics 2020-03-25 Tengfeng Zhu , Junyi Huang , Zhichao Ruan

When inverting solar spectra, image degradation effects that are present in the data are usually approximated or not considered. We develop a data reduction method that takes these issues into account and minimizes the resulting errors. By…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 M. van Noort

The recent years have given rise to a large number of techniques for "looking around corners", i.e., for reconstructing occluded objects from time-resolved measurements of indirect light reflections off a wall. While the direct view of…

Image and Video Processing · Electrical Eng. & Systems 2023-07-19 Jonathan Klein , Martin Laurenzis , Matthias B. Hullin , Julian Iseringhausen