Modification of Colors in Images for Enhancing the Visual Perception of Protanopes

Part 2: MHDW WorkshopInternational audienceThe purpose of this paper is to design and to implement proper color modification methods for enhancing visual perception of digital images for people with protanopia (one of the types of Color Vision Deficiency). This paper proposes one simulation method and two daltonization methods for the modification of digital colored images, implementing the additional step of quantization for a faster modification of colors which are not correctly perceived. In order to avoid color confusion a color checking module is implemented and optimal daltonization parameters are selected. The ultimate objective of this paper is to minimize the total processing time to such an extent that it is possible to apply the proposed methods to real-time sequences (online video). The entire application is tested in a set of artificial and real images, while the performance of the proposed algorithms is evaluated in an appropriately selected set of colored images

Forme des courbes de sensibilité au contraste des mécanismes colorés isolés en vision fovéale et périphérique

Summary : Change in shape of contrast sensitivity functions of isolated colour mechanisms for foveal and peripheral vision. The change in shape of contrast sensitivity functions of isolated colour mechanisms was studied for sinusoidal luminance pattern in steady-state or counter-phase flicker condition, and for foveal and peripheral presentation. Isolation of the colour mechanisms was obtained with selective chromatic adaptation. In these experimental conditions, it was observed that the contrast sensitivity functions were of a bandpass type for the isolated colour mechanisms. This bandpass characteristic is greater in peripheral presentation than in foveal presentation. Key-words : colour mechanisms, contrast sensitivity.Résumé On étudie, pour des mécanismes colorés isolés, en vision fovéale et en vision périphérique, l'évolution des courbes de sensibilité au contraste en fonction de la fréquence spatiale. Les mécanismes colorés ont été isolés par adaptation chromatique sélective. Le test est un réseau à profil sinusoïdal de luminance, présenté sans ou avec inversion de phase. Dans ces conditions expérimentales, on met en évidence le caractère passe-bande des fonctions de sensibilité au contraste pour les trois mécanismes colorés isolés et on montre que ce caractère est plus marqué en vision périphérique qu'en vision fovéale. Mots clefs : sensibilité au contraste, mécanismes colorés.Bourdy C., Vienot F., Monot A., Chiron A. Forme des courbes de sensibilité au contraste des mécanismes colorés isolés en vision fovéale et périphérique. In: L'année psychologique. 1982 vol. 82, n°1. pp. 19-27

Prognostic nomogram and score to predict overall survival in locally advanced untreated pancreatic cancer (PROLAP)

Background: The management of locally advanced pancreatic cancer (LAPC) patients remains controversial. Better discrimination for overall survival (OS) at diagnosis is needed. We address this issue by developing and validating a prognostic nomogram and a score for OS in LAPC (PROLAP). Methods: Analyses were derived from 442 LAPC patients enrolled in the LAP07 trial. The prognostic ability of 30 baseline parameters was evaluated using univariate and multivariate Cox regression analyses. Performance assessment and internal validation of the final model were done with Harrell's C-index, calibration plot and bootstrap sample procedures. On the basis of the final model, a prognostic nomogram and a score were developed, and externally validated in 106 consecutive LAPC patients treated in Besançon Hospital, France. Results: Age, pain, tumour size, albumin and CA 19-9 were independent prognostic factors for OS. The final model had good calibration, acceptable discrimination (C-index=0.60) and robust internal validity. The PROLAP score has the potential to delineate three different prognosis groups with median OS of 15.4, 11.7 and 8.5 months (log-rank P<0.0001). The score ability to discriminate OS was externally confirmed in 63 (59%) patients with complete clinical data derived from a data set of 106 consecutive LAPC patients; median OS of 18.3, 14.1 and 7.6 months for the three groups (log-rank P<0.0001). Conclusions: The PROLAP nomogram and score can accurately predict OS before initiation of induction chemotherapy in LAPC-untreated patients. They may help to optimise clinical trials design and might offer the opportunity to define risk-Adapted strategies for LAPC management in the future

On the Role of the Board of Statutory Auditors in Italian Listed Companies

This paper discusses the role of the board of statutory auditors as a monitoring device within the prevailing Italian corporate governance system, characterised by the presence of a strong blockholder. We describe the structure and functioning of the board of statutory auditors in the listed companies in terms of size, composition, method of appointment, powers, and duties after the changes due to the Draghi reform and the Preda Code of conduct. Copyright Blackwell Publishing Ltd. 2004.