The image of an opaque object is created by observing the reflection of the light incident on its surface. The dichromatic reflection model describes the surface reflection as the sum of two components, diffuse and specular terms. The specular reflection component is usually strong in its intensity and polarized significantly compared to the diffuse components. On the other hand, the intensity of the diffuse component is weak and it tends to be unpolarized except near occluding contours. Thus, the observation of an object through a rotating polarizer approximately yields images containing constant diffuse component and specular component of different intensity. In this paper, we show that diffuse and specular components of surface reflection can be separated as two independent components when we apply Independent Component Analysis to the images observed through a polarizer of different orientations. We give a separation simulation of artificial data and also give some separation results of real scenes.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1109/TPAMI.2004.1273960 | DOI Listing |
Sensors (Basel)
December 2024
Department of Electrical Engineering, Chinese Culture University, Taipei 11114, Taiwan.
This paper presents an effective three-dimensional (3D) surface reconstruction technique aimed at profiling composite surfaces with both specular and diffuse reflectance. Three-dimensional measurements based on fringe projection techniques perform well on diffuse reflective surfaces; however, when the measurement targets contain both specular and diffuse components, the efficiency of fringe projection decreases. To address this issue, the proposed technique integrates digital holography into the fringe projection setup, enabling the simultaneous capture of both specular and diffuse reflected light in the same optical path for full-field surface profilometry.
View Article and Find Full Text PDFLangmuir
December 2024
Engineering Technology Research Center of Henan Province for MEMS Manufacturing and Application, School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou 450001, China.
Gas transport through nanochannels has aroused significant interest in many fields. Recently, "ballistic transport" of gas was observed through a two-dimensional graphene nanochannel, and it causes a peculiar enhancement compared to the predictions of the Knudson theory. Many studies attributed this effect to the specular reflection caused by the atomically smooth surface of the channel.
View Article and Find Full Text PDFJ Imaging
October 2024
College of Automation & Information Engineering, Xi'an University of Technology, Xi'an 710048, China.
Langmuir
November 2024
Laboratoire Charles Coulomb (L2C), Univ. Montpellier, CNRS, Montpellier 34095, France.
The study delves into the adsorption of sunflower proteins at the air/water interface using specular X-ray reflection. The research involved fitting models of the protein films to the reflectivity data, resulting in detailed images of the X-ray scattering length density profiles perpendicular to the air/water interface. The sunflower protein isolate that is examined consists of multiple components, and the study proposes a transition from a 1-slab model to a 4-slab model to represent the changing layer structure over time.
View Article and Find Full Text PDFLangmuir
November 2024
School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China.
Colloidal photonic structures with the ability to control and manipulate light propagation offer long-term color stability, low optical loss, and angle-dependent color properties, while combinations of different photonic structures across multiple scales provide an extensive color range and enhanced optical functionalities, presenting significant potential for advanced anticounterfeiting applications. However, the proper design or manufacture of such complex structures is still challenging. In this study, amorphous photonic structures (APSs) with thin film interference (TFI) effects were fabricated for multilevel anticounterfeiting.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!