Color Models and Illumination Changes

Color model representation allows characterizing in a quantitative manner, any defined color spectrum of visible light, i.e. with a wavelength between 400nm and 700nm. To accomplish that, each model, or color space, is associated with a function that allows mapping the spectral power distribution of the visible electromagnetic radiation, in a space defined by a set of discrete values that quantify the color components composing the model. Some color spaces are sensitive to changes in lighting conditions. Others assure the preservation of certain chromatic features, remaining immune to these changes. Therefore, it becomes necessary to identify the strengths and weaknesses of each model in order to justify the adoption of color spaces in image processing and analysis techniques. This chapter will address the topic of digital imaging, main standards and formats. Next we will set the mathematical model of the image acquisition sensor response, which enables assessment of the various color spaces, with the aim of determining their invariance to illumination changes.

Partidos políticos e direito de oposição a Pirro

Art. 114º da Constituição da República Portuguesa: “1. Os partidos políticos participam nos órgãos baseados no sufrágio universal e directo, de acordo com a sua representatividade eleitoral. 2. É reconhecido às minorias o direito de oposição democrática, nos termos da Constituição e da lei. 3. Os partidos políticos representados na Assembleia da República e que não façam parte do Governo gozam, designadamente, do direito de serem informados regular e directamente pelo Governo sobre o andamento dos principais assuntos de interesse público, de igual direito gozando os partidos políticos representados nas Assembleias Legislativas das regiões autónomas e em quaisquer outras assembleias designadas por eleição directa relativamente aos correspondentes executivos de que não façam parte.”. § Article 114 of the Constitution of the Portuguese Republic. "1. Political parties shall participate in organs based on direct and universal suffrage, according to their electoral representation. 2. It is recognized minorities the right to democratic opposition, under the Constitution and the law. 3. Political parties represented in Parliament and not forming part of the Government shall, in particular, the right to be informed regularly and directly by the Government on the progress of the main matters of public interest, equal rights enjoying the political parties represented in Legislative Assemblies of the autonomous regions and any other assemblies formed through direct elections with respect to the corresponding executives who are not part. ".