Analysis of Hue Spectra During Storage of Pepper (Capsicum annuum)

Color information is widely used in non-destructive quality assessment of perishable horticultural produces. The presented work investigated color changes of pepper (Capsicum annuum L.) samples received from retail system. The effect of storage temperature (10±2°C and 24±4°C) on surface color and firmness was analyzed. Hue spectra was calculated using sum of saturations. A ColorLite sph850 (400-700nm) spectrophotometer was used as reference instrument. Dynamic firmness was measured on three locations of the surface: tip cap, middle and shoulder. Significant effects of storage conditions and surface location on both color and firmness were observed. Hue spectra responded sensitively to color development of pepper. Prediction model (PLS) was used to estimate dynamic firmess based on hue spectra. Accuracy was very different depending on the location. Firmness of the tip cap was predicted with the highest accuracy (RMSEP=0.0335). On the other hand, middle region cannot be used for such purpose. Due to the simplicity and rapid processing, analysis of hue spectra is a promising tool for evaluation of color in postharvest and food industry

A Display Calibration Technique based on Invariant Human Colour Mechanisms

When human observers are asked to adjust a coloured light such that it appears neither red nor green, or such that it appears neither yellow nor blue, most colour-normal observers have no difficulty in making these adjustments. These hue judgements are not significantly influenced by language or age [Saunders and van Brakel 1997] and individual differences in colour sensitivity are not reflected in the unique-hue settings [Webster et al. 2000]. The human colour system seems to be able to calibrate itself so that there is a remarkable agreement across observers in relation to these unique-hue judgements. Here we show how we can use the invariance of these unique-hue judgements to develop a colour calibration technique for display devices, which eliminates the need for an external calibration standard or a measurement device

Object oriented design of a thermo-mechanical FEM code

An object oriented design is presented for a computer program that can perform\ud thermo-mechanically coupled analyzes. The target of the design is a \ud exible and robust\ud computer program. It should be easy to adapt and extend, re-using existing code, without\ud interfering with already established algorithms.\ud The program uses publicly available toolkits that are currently emerging as C++ pack-\ud ages. First of all the Standard C++ Library (formerly Standard Template Library) is\ud used for packing items in container classes. Secondly the matrix and vector operations\ud are derived from the Template Numerical Toolkit (TNT) and �nally (not essentially for\ud the numerical part) a graphical user interface is made, based on the wxWindows package,\ud that can generate a GUI for Motif and MS-Windows with the same code.\ud Attention is given to the design of classes such as speci�c elements and material classes\ud based on more general classes. A hierarchy of classes is constructed where general behavior\ud is put high in the hierarchy and speci�c behavior low. The choice between inheritance and\ud aggregation is made at several levels

Photorealistic Style Transfer with Screened Poisson Equation

Recent work has shown impressive success in transferring painterly style to images. These approaches, however, fall short of photorealistic style transfer. Even when both the input and reference images are photographs, the output still exhibits distortions reminiscent of a painting. In this paper we propose an approach that takes as input a stylized image and makes it more photorealistic. It relies on the Screened Poisson Equation, maintaining the fidelity of the stylized image while constraining the gradients to those of the original input image. Our method is fast, simple, fully automatic and shows positive progress in making a stylized image photorealistic. Our results exhibit finer details and are less prone to artifacts than the state-of-the-art.Comment: presented in BMVC 201

Effect of electrical stimulation and others genetic and environmental factors on colour of lamb meat

The research aimed to assess the effect of breed, sex, age at slaughter, rearing system and electrical stimulation on some colorimetric characteristics measured on the muscles Longissimus dorsi (LD), Gluteobiceps (Gb), Semimembranosus (Sm) and Rectus femoris (RF) of lambs belonging to the genetic types Gentile di Puglia (GP), Ile de France (IF) and the cross-breeds F1, F2 and F3. The IF lambs provided meat with the highest value of hue and lightness and the lowest chroma and redness. The F1 lambs showed the highest values of redness while the F2 crossbreed significantly differed from the other three genetic types only in pH, which was always the lowest. The F3 crossbreed revealed similar behaviour to the other genetic types, except for the pH which was always higher than in GP, F1 and F2. The differences between sexes were restricted to L* and pH values, being higher in the male. The lambs slaughtered at 56 days showed high a* values, while b* and hue were on average higher in younger lambs (35 days). The lambs reared with maternal milk in comparison with the artificially reared ones provided meat with the highest a* chroma and b* and the lowest hue values. Electrical stimulation of the carcass seems to have produced the same effects as the usual ageing time in cold store. The RF muscle provided the brightest meat; Sm showed the highest values of b* and chroma; LD provided the “darkest” meat and the lowest values of b* and hue; Gb produced a lower a* value than muscles LD, RF and Sm

A Robust Hue Descriptor

A hue descriptor based on Logvinenko’s illuminantinvariant object colour atlas [1] is tested in terms of how well it maps hues to the hue names found in Moroney’s Colour Thesaurus [2] [3] and how well it maps hues of Munsell papers to their corresponding Munsell hue designator. Called the KSM hue descriptor, it correlates hue with the central wavelength of a Gaussian-shaped reflectance function. An important feature of this representation is that the set of hue descriptors inherits the illuminate invariant property of Logvinenko’s object colour atlas. Despite the illuminant invariance of the atlas and the hue descriptors, metamer mismatching means that colour stimulus shift [4] can occur, which will inevitably lead to some hue shifts. However, tests show that KSM hue is robust in the sense that it is much more stable under a change of illuminant than CIELAB hue

Cosmological structure formation shocks and cosmic rays in hydrodynamical simulations

Cosmological shock waves during structure formation not only play a decisive role for the thermalization of gas in virializing structures but also for the acceleration of relativistic cosmic rays (CRs) through diffusive shock acceleration. We discuss a novel numerical treatment of the physics of cosmic rays in combination with a formalism for identifying and measuring the shock strength on-the-fly during a smoothed particle hydrodynamics simulation. In our methodology, the non-thermal CR population is treated self-consistently in order to assess its dynamical impact on the thermal gas as well as other implications on cosmological observables. Using this formalism, we study the history of the thermalization process in high-resolution hydrodynamic simulations of the Lambda cold dark matter model. Collapsed cosmological structures are surrounded by shocks with high Mach numbers up to 1000, but they play only a minor role in the energy balance of thermalization. However, this finding has important consequences for our understanding of the spatial distribution of CRs in the large-scale structure. In high resolution simulations of galaxy clusters, we find a low contribution of the averaged CR pressure, due to the small acceleration efficiency of lower Mach numbers of flow shocks inside halos and the softer adiabatic index of CRs. However, within cool core regions, the CR pressure reaches equipartition with the thermal pressure leading there to a lower effective adiabatic index and thus to an enhanced compressibility of the central intracluster medium. This effect increases the central density and pressure of the cluster and thus the resulting X-ray emission and the central Sunyaev-Zel'dovich flux decrement. The integrated Sunyaev-Zel'dovich effect, however, is only slightly changed.Comment: 6 pages, 3 figures, to appear in the Proceedings of "Heating vs. Cooling in Galaxies and Clusters of Galaxies", August 2006, Garching (Germany), full resolution version available at http://www.cita.utoronto.ca/~pfrommer/Proceedings/Garching.pd

Color gamut mapping in a hue-linearized CIELAB color space

Color gamut mapping plays a crucial role in color management. Depending on the application, it is sometimes desirable to perform color gamut mapping by shifting the lightness and compressing the chroma of an out-of-gamut color while preserving the perceived hue of the color. The term perceived hue is used to distinguish between the visual sensation of hue and metric hue angle (e.g., CIELAB hue angle (hab) ). If a gamut-mapping task constrains CIELAB metric hue angle in the blue region of CIELAB, a perceived-hue shift will result. Due to these nonlinearities, two hue-linearized versions of the CIELAB color space were generated, one from the Hung and Berns visual data (1995) and one from the Ebner and Fairchild data set (1998). Both data sets consist of visually mapped hue data to planes of constant visual hue. These modified versions of the CIELAB color space were psychophysically tested for their hue-linearity characteristics against the CIELAB color space. The results of these experiments show that, in the blue region of CIELAB, the hue-corrected color spaces are more visually uniform and perform better than CIELAB in gamut mapping situations with respect to perceived hue. However, the CIELAB color space performed as good as or better than either hue-corrected spaces outside of the blue region

A Hierarchical Segmentation Algorithm for Face Analysis. Application to Lipreading

International audienceA hierarchical algorithm for face analysis is presented in this paper. A color video sequence of speaker's face is acquired, under natural lighting conditions and without any particular make-up. The application aims at providing geometrical features of the face for scalable video transmission when no specific model of the speaker face is assumed. First, a logarithmic hue transform is performed from RGB to HI (hue, intensity) color space. Next, a Markov random field modeling regularizes motion and hue information within a spatiotemporal neighborhood. The hierarchical segmentation labels the different areas of the face. Results are shown on the lower part of the face and compared with standard color segmentation algorithm (fuzzy c-means). A speaker's lip shape with inner and outer borders is extracted from the final labeling and used to initialize an active contours stage