Categorical color mapping for gamut mapping: II. Using block average image

1998 ◽  
Author(s):  
Hideto Motomura
Keyword(s):  
Color Mapping ◽  
Gamut Mapping ◽  
Average Image ◽  
Block Average

scholarly journals Color-gamut mapping in the non-uniform CIE-1931 space with perceptual hue fidelity constraints for SMPTE ST.2094-40 standard

2020 ◽  
Vol 9 ◽  
Author(s):  
Chang Su ◽  
Li Tao ◽  
Yeong Taeg Kim
Keyword(s):  
High Performance ◽  
Dynamic Range ◽  
Human Subjects ◽  
Uniform Space ◽  
High Dynamic Range ◽  
Appearance Model ◽  
Visual Responses ◽  
Color Gamut ◽  
Color Mapping ◽  
Gamut Mapping

Abstract As high-dynamic range (HDR) and wide-color gamut (WCG) contents become more and more popular in multimedia markets, color mapping of the distributed contents to different rendering devices plays a pivotal role in HDR distribution eco-systems. The widely used and economic gamut-clipping (GC)-based techniques perform poorly in mapping WCG contents to narrow gamut devices; and high-performance color-appearance model (CAM)-based techniques are computationally expensive to commercial applications. In this paper, we propose a novel color gamut mapping (CGM) algorithm to solve the problem. By introducing a color transition/protection zone (TPZ) and a set of perceptual hue fidelity constraints into the CIE-1931 space, the proposed algorithm directly carries out CGM in the perceptually non-uniform space, thus greatly decreases the computational complexity. The proposed TPZ effectively achieves a reasonable compromise between saturation preserving and details protection in out-of-gamut colors. The proposed hue fidelity constraints reference the measurements of human subjects' visual responses, thus effectively preserve the perceptual hue of the original colors. Experimental results show that the proposed algorithm clearly outperforms the GC-CGM, and performs similarly or better than the expensive CAM-CGM. The proposed algorithm is real-time and hardware friendly. It is an important supplement of the SMPTE ST.2094-40 standard.

A testing paradigm for quantifying ICC profilers

2019 ◽  
Vol 2019 (1) ◽  
pp. 80-85
Author(s):  
Pooshpanjan Roy Biswas ◽  
Alessandro Beltrami ◽  
Joan Saez Gomez
Keyword(s):  
Digital Camera ◽  
Visual Assessment ◽  
Just Noticeable Difference ◽  
Color Management ◽  
Color Gamut ◽  
Gamut Mapping ◽  
Digital File ◽  
Mapping Process ◽  
Testing Paradigm

To reproduce colors in one system which differs from another system in terms of the color gamut, it is necessary to use a color gamut mapping process. This color gamut mapping is a method to translate a specific color from a medium (screen, digital camera, scanner, digital file, etc) into another system having a difference in gamut volume. There are different rendering intent options defined by the International Color Consortium [5] to use the different reproduction goals of the user [19]. Any rendering intent used to reproduce colors, includes profile engine decisions to do it, i.e. looking for color accuracy, vivid colors or pleasing reproduction of images. Using the same decisions on different profile engines, the final visual output can look different (more than one Just Noticeable Difference[16]) depending on the profile engine used and the color algorithms that they implement. Profile performance substantially depends on the profiler engine used to create them. Different profilers provide the user with varying levels of liberty to design a profile for their color management needs and preference. The motivation of this study is to rank the performance of various market leading profiler engines on the basis of different metrics designed specifically to report the performance of particular aspects of these profiles. The study helped us take valuable decisions regarding profile performance without any visual assessment to decide on the best profiler engine.

AVERAGE IMAGE CREATION METHODS USING REFERENCE LANDMARKS

2017 ◽  
Vol 61 ◽  
pp. 105-109
Author(s):  
G. V. Syroezhkin ◽  
◽  
A. B. Savinetsky ◽  
A. M. Maurer ◽  
◽  
...  
Keyword(s):  
Image Creation ◽  
Average Image

scholarly journals Coronary Flow and Reserve by Enhanced Transthoracic Doppler Trumps Coronary Anatomy by Computed Tomography in Assessing Coronary Artery Stenosis

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 245
Author(s):  
Carlo Caiati ◽  
Arnaldo Scardapane ◽  
Fortunato Iacovelli ◽  
Paolo Pollice ◽  
Teresa Immacolata Achille ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Coronary Angiography ◽  
Flow Velocity ◽  
Coronary Flow ◽  
Invasive Coronary Angiography ◽  
Coronary Anatomy ◽  
Color Mapping ◽  
Flow Reserve ◽  
Mild Stenosis ◽  
Iodinated Contrast

We report the case of a 71-year-old patient with many risk factors for coronary atherosclerosis, who underwent computed coronary angiography (CTA), in accordance with the guidelines, for recent onset atypical chest pain. CTA revealed critical (>50% lumen diameter narrowing) stenosis of the proximal anterior descending coronary, and the patient was scheduled for invasive coronary angiography (ICA). Before ICA he underwent enhanced transthoracic echo-Doppler (E-Doppler TTE) for coronary flow detection by color-guided pulsed-wave Doppler recording of the left main (LMCA) and whole left anterior descending coronary artery (LAD,) along with coronary flow reserve (CFR) in the distal LAD calculated as the ratio, of peak flow velocity during i.v. adenosine (140 mcg/Kg/m) to resting flow velocity. E-Doppler TTE mapping revealed only mild stenosis (28% area narrowing) of the mid LAD and a CFR of 3.20, in perfect agreement with the color mapping showing no flow limiting stenosis in the LMCA and LAD. ICA revealed only a very mild stenosis in the mid LAD and mild atherosclerosis in the other coronaries (intimal irregularities). Thus, coronary stenosis was better predicted by E-Doppler TTE than by CTA. Coronary flow and reserve as assessed by E-Doppler TTE trumps coronary anatomy as assessed by CTA, without exposing the patient to harmful radiation and iodinated contrast medium.

scholarly journals One-shot BRDF imaging system to obtain surface properties

2021 ◽  
Author(s):  
Hiroshi Ohno ◽  
Takahiro Kamikawa
Keyword(s):  
Surface Properties ◽  
Imaging System ◽  
Reconstruction Method ◽  
Surface Reflectance ◽  
Bidirectional Reflectance Distribution Function ◽  
Bidirectional Reflectance ◽  
Color Mapping ◽  
System A ◽  
Cone Surface ◽  
Bidirectional Reflectance Distribution

AbstractThe bidirectional reflectance distribution function (BRDF) that describes an angle-resolved distribution of surface reflectance is available for characterizing surface properties of a material. A one-shot BRDF imaging system can capture an in-plane color mapping of light direction extracted from a surface BRDF distribution. A surface roughness identification method is then proposed here using the imaging system. A difference between surface properties of a matt paper and a glossy paper is experimentally shown to be detected using the method. A surface reconstruction method of an axisymmetric micro-object using the imaging system is also proposed here. The imaging system experimentally shows that it can reconstruct an axisymmetric aluminium cone surface with a height of 37 μm.

P‐13.11: A Color Gamut Mapping Reducing the Influence of IR‐drop in OLED Displays

2019 ◽  
Vol 50 (S1) ◽  
pp. 985-987
Author(s):  
Junting Ouyang ◽  
Bojia Lyu ◽  
DZ Peng ◽  
Kang Yang ◽  
Xiangzi Kong ◽  
...  
Keyword(s):  
Color Gamut ◽  
Gamut Mapping ◽  
Ir Drop
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