Reduction of smoothing levels in LUM FTC filter structure

In this paper, we analyze the possibility of the reduction of smoothing levels in 3-D adaptive lower-upper-middle (LUM) smoother based on the fixed threshold control (FTC). Besides the excellent noise attenuation capability with the simultaneous signal-detail preservation, recently introduced LUM FTC filter with a window size N is characterized by a relatively complex structure, where an estimate is formed according to (N +1)/2 decision rules. This fact can constrain its possible hardware filter implementation in real motion video applications. In order to simplify the filter complexity, however, to retain the excellent filter performance simultaneously, we propose two approaches such as linear reduction of smoothing levels and optimal reduction based on genetic algorithm.Dans cet article, nous analysons la possibilité de réduire le nombre de niveaux de lissage d'un filtre LUM (lower-upper-middle) adaptatif 3-D basé sur un contrôle par seuils fixes (FTC = fixed threshold control). Outre son excellente capacité d'atténuation du bruit tout en assurant la conservation des détails, le filtre LUM FTC avec une fenêtre de taille N, est caractérisé par une structure relativement complexe, où l'estimation de la valeur de sortie est faite en fonction de (N + 1)/2 règles de décision. Ceci peut entraver l'implémentation matérielle de tels filtres dans des applications vidéo temps réel. Afin de simplifier la complexité du filtre tout en gardant ses excellentes performances, nous proposons deux approches qui sont la réduction linéaire du nombre de niveaux de lissage et la réduction optimale basée sur un algorithme génétique

Perceptual digital imaging: methods and applications

Visual perception is a complex process requiring interaction between the receptors in the eye that sense the stimulus and the neural system and the brain that are responsible for communicating and interpreting the sensed visual information. This process involves several physical, neural, and cognitive phenomena whose understanding is essential to design effective and computationally efficient imaging solutions. Building on advances in computer vision, image and video processing, neuroscience, and information engineering, perceptual digital imaging greatly enhances the capabilities of traditio

A cost-effective encryption scheme for color images

A new secret sharing scheme suitable for encrypting color images is introduced. The scheme, which can be viewed as a costeffective, private-key cryptosystem, encrypts the secret color image into two color shares with dimensions identical to those of the original secret input. Cryptographic operations performed at the bit levels are used to alter both the spectral correlation among the RGB color components and the spatial correlation of the neighboring color vectors in the secret image. The original image is decrypted with perfect reconstruction using inverse logical operations which are applied to the noise-like color shares. The scheme can be used in secure transmission of digital imaging material over untrusted networks or it can serve as stand-alone image encryption solution. r 2005 Elsevier Ltd. All rights reserved. 1

Combined forward and backward anisotropic diffusion filtering of color images

In this paper a new approach to the problem of edge preserving smoothing is proposed and evaluated. The new algorithm is based on the combined forward and backward anisotropic diffusion with incorporated time dependent cooling process. This method is able to efficiently remove image noise while preserving and enhancing image edges, lines and corners. The new method has been applied for the denoising of typical airborne images. Obtained results confirm good properties of the new noise reduction technique and its usefulness for the enhancement of various kinds of remotely sensed data in different detection and recognition systems [1,2]. 1 ANISOTROPIC DIFFUSION Perona and Malik [3] formulate the anisotropic diffusion filter as a process that encourages intraregional smoothing, while inhibiting interregional denoising. The Perona-Malik (P-M) nonlinear diffusion equation is of the form [3-7]:

Digital zooming for color filter array-based image sensors

In thispaper, zooming methodswhich operate directly on color filter array (CFA) data are proposed, analyzed, and evaluated. Under the proposed framework enlarged spatial resolution images are generated directly from the CFA-based image sensors. The reduced computational complexity of the proposed schemes makes them ideal for real-time surveillance systems, industrial strength computer vision solutions, and mobile sensor-based visual systems. Simulation studies reported here indicate that the new methods (i) produce excellent results, in terms of both objective and subjective evaluation metrics, and (ii) outperform conventional zooming schemes operating in the RGB domain. r 2005 Elsevier Ltd. All rights reserved. 1