THE EFFECT OF CONDTIONAL DISCRIMINATION TRAINING ON CHOICE MAKING IN CHILDREN DURING `PRE-GAMBLING\u27 ACTIVITIES

Past research has shown conditional discrimination training of a stimulus to change its function by manipulating variables within the contingencies (e.g., Johnson & Dixon, 2009), and the present study attempted to extend this research. Experimenters exposed 3 children (ages 6-9 years) to a computer program that trained participant to discriminate between two contextual cures (blue and yellow) representing more than and less than. All three participants will demonstrate an increased preference toward the color that had been paired with more than during both conditional discrimination training phases

Color-contrast landmark detection and encoding in outdoor images

International Conference on Computer Analysis of Images and Patterns (CAIP), 2005, Versalles (Francia)This paper describes a system to extract salient regions from an outdoor image and match them against a database of previously acquired landmarks. Region saliency is based mainly on color contrast, although intensity and texture orientation are also taken into account. Remarkably, color constancy is embedded in the saliency detection process through a novel color ratio algorithm that makes the system robust to illumination changes, so common in outdoor environments. A region is characterized by a combination of its saliency and its color distribution in chromaticity space. The newly acquired landmarks are compared with those already stored in a database, through a quadratic distance metric of their characterizations. Experimentation with a database containing 68 natural landmarks acquired with the system yielded good recognition results, in terms of both recall and rank indices. However, the discrimination between landmarks should be improved to avoid false positives, as suggested by the low precision index.This work was supported by the project 'Sistema reconfigurable para la navegación basada en visión de robots caminantes y rodantes en entornos naturales.' (00).Peer Reviewe

Global and local characterization of rock classification by Gabor and DCT filters with a color texture descriptor

In the automatic classification of colored natural textures, the idea of proposing methods that reflect human perception arouses the enthusiasm of researchers in the field of image processing and computer vision. Therefore, the color space and the methods of analysis of color and texture, must be discriminating to correspond to the human vision. Rock images are a typical example of natural images and their analysis is of major importance in the rock industry. In this paper, we combine the statistical (Local Binary Pattern (LBP) with Hue Saturation Value (HSV) and Red Green Blue (RGB) color spaces fusion) and frequency (Gabor filter and Discrete Cosine Transform (DCT)) descriptors named respectively Gabor Adjacent Local Binary Pattern Color Space Fusion (G-ALBPCSF) and DCT Adjacent Local Binary Pattern Color Space Fusion (D-ALBPCSF) for the extraction of visual textural and colorimetric features from direct view images of rocks. The textural images from the two G-ALBPCSF and D-ALBPCSF approaches are evaluated through similarity metrics such as Chi2 and the intersection of histograms that we have adapted to color histograms. The results obtained allowed us to highlight the discrimination of the rock classes. The proposed extraction method provides better classification results for various direct view rock texture images. Then it is validated by a confusion matrix giving a low error rate of 0.8% of classification

Chromatic Illumination Discrimination Ability Reveals that Human Colour Constancy Is Optimised for Blue Daylight Illuminations

The phenomenon of colour constancy in human visual perception keeps surface colours constant, despite changes in their reflected light due to changing illumination. Although colour constancy has evolved under a constrained subset of illuminations, it is unknown whether its underlying mechanisms, thought to involve multiple components from retina to cortex, are optimised for particular environmental variations. Here we demonstrate a new method for investigating colour constancy using illumination matching in real scenes which, unlike previous methods using surface matching and simulated scenes, allows testing of multiple, real illuminations. We use real scenes consisting of solid familiar or unfamiliar objects against uniform or variegated backgrounds and compare discrimination performance for typical illuminations from the daylight chromaticity locus (approximately blue-yellow) and atypical spectra from an orthogonal locus (approximately red-green, at correlated colour temperature 6700 K), all produced in real time by a 10-channel LED illuminator. We find that discrimination of illumination changes is poorer along the daylight locus than the atypical locus, and is poorest particularly for bluer illumination changes, demonstrating conversely that surface colour constancy is best for blue daylight illuminations. Illumination discrimination is also enhanced, and therefore colour constancy diminished, for uniform backgrounds, irrespective of the object type. These results are not explained by statistical properties of the scene signal changes at the retinal level. We conclude that high-level mechanisms of colour constancy are biased for the blue daylight illuminations and variegated backgrounds to which the human visual system has typically been exposed

Design for people with cataract

katedra: KOD; přílohy: 1 CD ROM; rozsah: 87Práce se zabývá studií rozlišování barev u skupiny osob s kataraktou - šedým zákalem. Měření rozlišování barev se provádělo pomocí FM 100 Hue testu. Vyhodnocovalo se procentuální zlepšení vnímání barev před a po operaci katarakty a porovnávaly se výsledky rozlišování barev mezi osobami s kataraktou a osobami bez katarakty. Dále se pro zvolené skupiny osob s kataraktou určily oblasti, ve kterých byly barvy rozlišovány s nejmenší úspěšností. Výsledky se také porovnávaly s charakteristikami vad vnímání barev. Simulace sníženého vnímání barev se uskutečnila pomocí počítačového programu Color Vision Filter. Navržené postupy programu umožňují podle výsledků FM 100 Hue testu přetransformovat scénu do barev, jak je vidí testovaná osoba. Získané znalosti je možné dále využít pro specifický design určený osobám se sníženým vnímáním barev.This work investigates the color discrimination in a group of persons with cataract. Measurement of color discrimination was made using FM 100 Hue test. Author evaluated the percentage improvement in color perception before and after cataract surgery and compared the results of color discrimination between persons with cataract and persons without cataract. Furthermore, for selected groups of people with cataract have been identified the areas in which they distinguished colors with the least success. The results are then compared with the characteristics of color vision defects. Simulation of a reduced color perception was carried out using the computer program Color Vision Filter. Designed procedures allow the program to transform the scene into colors according to the results of FM 100 Hue test, as seen by the tested person. Gained knowledge can be used for specific design for persons with low color discrimination