This paper presents novel algorithmic and architectural solutions for real-time and power-efficient enhancement of images and video sequences. A programmable class of Retinex-like filters, based on the separation of the illumination and reflectance components, is proposed. The dynamic range of the input image is controlled by applying a suitable non-linear function to the illumination, while the details are enhanced by processing the reflectance. An innovative spatially recursive rational filter is used to estimate the illumination. Moreover, to improve the visual quality results of two-branch Retinex operators when applied to videos, a novel three-branch technique is proposed which exploits both spatial and temporal filtering. Real-time implementation is obtained by designing an Application Specific Instruction-set Processor (ASIP). Optimizations are addressed at algorithmic and architectural levels. The former involves arithmetic accuracy definition and linearization of non-linear operators; the latter includes customized instruction set, dedicated memory structure, adapted pipeline, bypasses, custom address generator, and special looping structures. The ASIP is synthesized in standard-cells CMOS technology and its performances are compared to known Digital signal processor (DSP) implementations of real-time Retinex filters. As a result of the comparison, the proposed algorithmic/architectural design outperforms state-of-art Retinex-like operators achieving the best trade-off between power consumption, flexibility, and visual quality

This work investigates the long-term stability\ud of suspensions of surfactant-free gold nanostars\ud with mean diameter of 78 ± 13 nm (measured from\ud tip to tip across the nanostar).We monitored the optical\ud and morphological properties of the nanostars over the\ud course of several days after synthesis by observing the\ud changes in the UV–visible absorption spectra and\ud mean radius of curvature of the nanostar tips. An aging\ud process can be observed, evident in the blunting of the\ud nanostar tips, leading to a blue shift in the absorption\ud maximum. Stability is greatly improved by depositing\ud on the nanostars a monolayer of mercaptopropionic\ud acid (MPA), possibly because of the formation of the\ud gold–sulfur (Au–S) bond that limits the mobility of the\ud Au atoms. Capping the nanostars with MPA is an easy\ud additional step for extending the stability of the\ud nanostars in suspension without significan

A novel scheme for edge-preserving image interpolation is introduced, which is based on the use of a simple nonlinear fillter which accurately reconstructs sharp edges. Simulation results show the superior performances of the proposed approach with respect to other interpolation techniques.

No abstract

No abstract