Deep Color Constancy Using Temporal Gradient Under Ac Light Sources

2021 ◽  
Author(s):  
Jeong-Won HA ◽  
JUN-Sang YOO ◽  
JONG-Ok KIM
Keyword(s):  
Color Constancy ◽  
Light Sources ◽  
Temporal Gradient

Partial Color Constancy of Isolated Surface Colors Examined by a Color-Naming Method

Perception ◽  
1989 ◽  
Vol 18 (1) ◽  
pp. 83-91 ◽  
Author(s):  
Keiji Uchikawa ◽  
Hiromi Uchikawa ◽  
Robert M Boynton
Keyword(s):  
Color Constancy ◽  
Color Naming ◽  
The State ◽  
Color Appearance ◽  
Chromatic Adaptation ◽  
Light Sources ◽  
Two Factors ◽  
The Subject ◽  
Spectral Distributions ◽  
Color Scales

Color samples selected from the OSA Uniform Color Scales set were viewed without any surround. Separate light sources were used to illuminate the samples and to control the state of adaptation of the subject, thereby separating two factors that are normally confounded. A color-naming procedure was used to assess shifts in color appearance produced by altering the spectral distributions of one or both light sources. The results confirm that chromatic adaptation, when it is the only factor operating, can mediate partial color constancy.

scholarly journals Dynamic Color Object Recognition Using Fuzzy Logic

2004 ◽  
Vol 8 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Napoleon H. Reyes ◽  
◽  
Elmer P. Dadios ◽  
Keyword(s):  
Object Recognition ◽  
Fuzzy Inference ◽  
Color Constancy ◽  
Human Perception ◽  
Light Sources ◽  
Inference System ◽  
Image Appearance ◽  
Color Descriptors ◽  
New Perspective ◽  
Color Object Recognition

This paper presents a novel Logit-Logistic Fuzzy Color Constancy (LLFCC) algorithm and its variants for dynamic color object recognition. Contrary to existing color constancy algorithms, the proposed scheme focuses on manipulating a color locus depicting the colors of an object, and not stabilizing the whole image appearance per se. In this paper, a new set of adaptive contrast manipulation operators is introduced and utilized in conjunction with a fuzzy inference system. Moreover, a new perspective in extracting color descriptors of an object from the rg-chromaticity space is presented. Such color descriptors allow for the reduction of the effects of brightness/darkness and at the same time adhere to human perception of colors. The proposed scheme tremendously cuts processing time by simultaneously compensating for the effects of a multitude of factors that plague the scene of traversal, eliminating the need for image pre-processing steps. Experiment results attest to its robustness in scenes with multiple white light sources, spatially varying illumination intensities, varying object position, and presence of highlights.

Computational Color Constancy under Multiple Light Sources

2020 ◽  
Vol 2020 (10) ◽  
pp. 135-1-135-6
Author(s):  
Jaeduk Han ◽  
Soonyoung Hong ◽  
Moon Gi Kang
Keyword(s):  
Computer Vision ◽  
Color Constancy ◽  
Artificial Light ◽  
Light Sources ◽  
Color Representation ◽  
Conventional Methods ◽  
Computational Color Constancy

Without sunlight, imaging devices typically depend on various artificial light sources. However, scenes captured with the artificial light sources often violate the assumptions employed in color constancy algorithms. These violations of the scenes, such as non-uniformity or multiple light sources, could disturb the computer vision algorithms. In this paper, complex illumination of multiple artificial light sources is decomposed into each illumination by considering the sensor responses and the spectrum of the artificial light sources, and the fundamental color constancy algorithms (e.g., gray-world, gray-edge, etc.) are improved by employing the estimated illumination energy. The proposed method effectively improves the conventional methods, and the results of the proposed algorithms are demonstrated using the images captured under laboratory settings for measuring the accuracy of the color representation.

Object Color Constancy for Outdoor Multiple Light Sources

2015 ◽  
pp. 369-378 ◽  
Author(s):  
Liangqiong Qu ◽  
Zhigang Duan ◽  
Jiandong Tian ◽  
Zhi Han ◽  
Yandong Tang
Keyword(s):  
Color Constancy ◽  
Light Sources

Color Constancy for Multiple Light Sources

2012 ◽  
Vol 21 (2) ◽  
pp. 697-707 ◽  
Author(s):  
A. Gijsenij ◽  
Rui Lu ◽  
T. Gevers
Keyword(s):  
Color Constancy ◽  
Light Sources

scholarly journals A NEW COLOR CORRECTION METHOD FOR UNDERWATER IMAGING

2015 ◽  
Vol XL-5/W5 ◽  
pp. 25-32 ◽  
Author(s):  
G. Bianco ◽  
M. Muzzupappa ◽  
F. Bruno ◽  
R. Garcia ◽  
L. Neumann
Keyword(s):  
Imaging Techniques ◽  
Color Space ◽  
Computational Cost ◽  
Color Constancy ◽  
Correction Method ◽  
Color Correction ◽  
Physical Parameters ◽  
Light Sources ◽  
Underwater Imaging ◽  
Opponent Color

Recovering correct or at least realistic colors of underwater scenes is a very challenging issue for imaging techniques, since illumination conditions in a refractive and turbid medium as the sea are seriously altered. The need to correct colors of underwater images or videos is an important task required in all image-based applications like 3D imaging, navigation, documentation, etc. Many imaging enhancement methods have been proposed in literature for these purposes. The advantage of these methods is that they do not require the knowledge of the medium physical parameters while some image adjustments can be performed manually (as histogram stretching) or automatically by algorithms based on some criteria as suggested from computational color constancy methods. One of the most popular criterion is based on gray-world hypothesis, which assumes that the average of the captured image should be gray. An interesting application of this assumption is performed in the Ruderman opponent color space lαβ, used in a previous work for hue correction of images captured under colored light sources, which allows to separate the luminance component of the scene from its chromatic components. In this work, we present the first proposal for color correction of underwater images by using lαβ color space. In particular, the chromatic components are changed moving their distributions around the white point (white balancing) and histogram cutoff and stretching of the luminance component is performed to improve image contrast. The experimental results demonstrate the effectiveness of this method under gray-world assumption and supposing uniform illumination of the scene. Moreover, due to its low computational cost it is suitable for real-time implementation.

Categorical color constancy under RGB-LED light sources

2018 ◽  
Vol 43 (5) ◽  
pp. 655-674 ◽  
Author(s):  
Ruiqing Ma ◽  
Ningfang Liao ◽  
Pengfei Yan ◽  
Keizo Shinomori
Keyword(s):  
Color Constancy ◽  
Light Sources ◽  
Led Light

Spatially Resolved Photoelectron Spectroscopy: Recent Progress and Future Plans

1990 ◽  
Vol 48 (2) ◽  
pp. 388-389
Author(s):  
A. M. Bradshaw
Keyword(s):  
Photoelectron Spectroscopy ◽  
Chemical Reactivity ◽  
Target Material ◽  
Orbital Energy ◽  
Light Sources ◽  
Analytical Technique ◽  
Hartree Fock ◽  
Spatially Resolved ◽  
Koopmans Theorem ◽  
Surface Analytical Technique

X-ray photoelectron spectroscopy (XPS or ESCA) was not developed by Siegbahn and co-workers as a surface analytical technique, but rather as a general probe of electronic structure and chemical reactivity. The method is based on the phenomenon of photoionisation: The absorption of monochromatic radiation in the target material (free atoms, molecules, solids or liquids) causes electrons to be injected into the vacuum continuum. Pseudo-monochromatic laboratory light sources (e.g. AlKα) have mostly been used hitherto for this excitation; in recent years synchrotron radiation has become increasingly important. A kinetic energy analysis of the so-called photoelectrons gives rise to a spectrum which consists of a series of lines corresponding to each discrete core and valence level of the system. The measured binding energy, EB, given by EB = hv−EK, where EK is the kineticenergy relative to the vacuum level, may be equated with the orbital energy derived from a Hartree-Fock SCF calculation of the system under consideration (Koopmans theorem).

Sign in / Sign up

Export Citation Format

Share Document