Results 61 to 70 of about 12,539 (191)

Ascertaining the Ideality of Photometric Stereo Datasets under Unknown Lighting

Algorithms, 2023
The standard photometric stereo model makes several assumptions that are rarely verified in experimental datasets. In particular, the observed object should behave as a Lambertian reflector, and the light sources should be positioned at an infinite ...
Elisa Crabu, Federica Pes, Giuseppe Rodriguez, Giuseppa Tanda   +3 more
doaj   +1 more source

Linear Differential Constraints for Photo-polarimetric Height Estimation

, 2017
In this paper we present a differential approach to photo-polarimetric shape estimation. We propose several alternative differential constraints based on polarisation and photometric shading information and show how to express them in a unified partial ...
Hancock, Edwin R., Ramamoorthi, Ravi, Smith, William A. P., Tozza, Silvia, Zhu, Dizhong   +4 more
core   +1 more source

Photometric Stereo by Hemispherical Metric Embedding [PDF]

Journal of Mathematical Imaging and Vision, 2017
Photometric Stereo methods seek to reconstruct the 3d shape of an object from motionless images obtained with varying illumination. Most existing methods solve a restricted problem where the physical reflectance model, such as Lambertian reflectance, is known in advance. In contrast, we do not restrict ourselves to a specific reflectance model. Instead,
Ofer Bartal, Nati Ofir, Yaron Lipman, Ronen Basri   +3 more
openaire   +3 more sources

Optical Flow Enables Hand Tracking With EyeGlove Low‐Cost Cameras in Confined Environments

Advanced Intelligent Systems, EarlyView.
A cost‐effective (<£150) hand‐wearable stereo vision system, EyeGlove, is proposed to support visual inspection in confined environments. The system integrates disjointed low‐cost cameras to enable dexterous camera manipulation and wearable display unit for real‐time interaction.
Erhui Sun, Xin Dong, Dragos Axinte, Andy Norton   +3 more
wiley   +1 more source

CONSERVATION MONITORING OF A HERITAGE CEILING BY PHOTOMETRIC STEREO [PDF]

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2012
Photographic survey techniques were employed to monitor the condition of the paintwork on the ceiling of the Queen's Staircase at Hampton Court Palace. Illumination was provided by a flash, mounted on an 8 metre telescopic mast, raised to approximately ...
L. MacDonald, I. Gibb, S. Robson
doaj   +1 more source

DRM-Based Colour Photometric Stereo Using Diffuse-Specular Separation for Non-Lambertian Surfaces

Journal of Imaging, 2022
This paper presents a photometric stereo (PS) method based on the dichromatic reflectance model (DRM) using colour images. The proposed method estimates surface orientations for surfaces with non-Lambertian reflectance using diffuse-specular separation ...
Boren Li, Tomonari Furukawa
doaj   +1 more source

Direct Monocular Odometry Using Points and Lines

, 2017
Most visual odometry algorithm for a monocular camera focuses on points, either by feature matching, or direct alignment of pixel intensity, while ignoring a common but important geometry entity: edges.
Scherer, Sebastian, Yang, Shichao
core   +1 more source

Speckle Skin‐Based Multimodal Tactile Perception for Fine Robotic Manipulation

Advanced Intelligent Systems, EarlyView.
SpeckleTac, a miniature vision‐based tactile sensor, utilizes a speckle‐pattern skin and optical flow‐based scalable virtual marker tracking. Combined with advanced algorithms, it achieves high‐resolution 3D surface reconstruction, precise contact perception, and stable grasping capabilities.
Jiayuan Zhang, Chong Wang, Yingao Xu, Shihan Wang, Houping Wu, Yulian Peng, Hongbo Wang   +6 more
wiley   +1 more source

An Optimal Experimental Design Approach for Light Configurations in Photometric Stereo [PDF]

, 2022
Hamza A. A. Gardi, Sebastian F. Walter, Christoph S. Garbe   +2 more
openalex   +1 more source

Rotatable Lens‐Based 3D Reconstruction Method for Monocular Vision Systems

SmartBot, EarlyView.
Accurate 3D reconstruction in confined environments remains challenging because conventional vision‐based measurement systems are difficult to maintain compactness without sacrificing accuracy. Here, the authors develop a rotatable lens‐based monocular vision system, which is the first time using the refraction of the light induced by a rotating wedge ...
Puchen Zhu, Zhanpeng Huang, Wenkai Lai, Xiaoyin Zheng, Yiding Nie, Yang Liu, Jiajun An, Daifeng Wang, Dongliang Fan, Xiao Li, Jian S. Dai, Xin Ma   +11 more
wiley   +1 more source