Semantic Segmentation with Labeling Uncertainty and Class Imbalance

Recently, methods based on Convolutional Neural Networks (CNN) achieved impressive success in semantic segmentation tasks. However, challenges such as the class imbalance and the uncertainty in the pixel-labeling process are not completely addressed. As such, we present a new approach that calculates a weight for each pixel considering its class and uncertainty during the labeling process. The pixel-wise weights are used during training to increase or decrease the importance of the pixels. Experimental results show that the proposed approach leads to significant improvements in three challenging segmentation tasks in comparison to baseline methods. It was also proved to be more invariant to noise. The approach presented here may be used within a wide range of semantic segmentation methods to improve their robustness.Comment: 15 pages, 9 figures, 3 table

Optical Properties of Hybrid Organic-Inorganic Materials and their Applications

Research on hybrid inorganic-organic materials has experienced an explosive growth since the 1980s, with the expansion of soft inorganic chemistry based processes. Indeed, mild synthetic conditions, low processing temperatures provided by \"chimie douce\" and the versatility of the colloidal state allow for the mixing of the organic and inorganic components at the nanometer scale in virtually any ratio to produce the so called hybrid materials. Today a high degree of control over both composition and nanostructure of these hybrids can be achieved allowing tunable structure-property relationships. This, in turn, makes it possible to tailor and fine-tune many properties (mechanical, optical, electronic, thermal, chemical.) in very broad ranges, and to design specific multifunctional systems for applications. In particular, the field of \"Hybrid-Optics\" has been very productive not only scientifically but also in terms of applications. Indeed, numerous optical devices based on hybrids are already in, or very close, to the market. This review describes most of the recent advances performed in this field. Emphasis will be given to luminescent, photochromic, NLO and plasmonic properties. As an outlook we show that the controlled coupling between plasmonics and luminescence is opening a land of opportunities in the field of \"Hybrid-Optics\"