We discuss a recently presented model for multiscale analysis of space-time sequences and its parallel implementation. Our nonlinear partial diierential equation, representing the multiscale analysis, lters the sequence while keeping of the space-time coherent structures. It combines the ideas of regularized Perona-Malik anisotropic diiusion and Galilean invariant movie multiscale analysis of A...

The use of low-level visual features to search and retrieve information in the multimedia databases has drawn much attention in the recent years [1,2]. Many of the existing techniques of image retrieval are based on image segmentation, which is a difficult task in many practical situations due to image noise and various compression artifacts. In this paper a novel approach to the problem of edg...

Partial differential equation (PDE)–based image processing has played a substantial role and become more popular in the recent years. In the application of weld defect detection, the PDE models can be applied for image smoothing and segmentation. In this study, anisotropic diffusion proposed by Perona Malik known as Perona Malik Anisotropic Diffusion (PMAD) model is used as a denoising process ...

This paper is about extending the classical Non-Local Means (NLM) denoising algorithm using general shapes instead of square patches. The use of various shapes enables to adapt to the local geometry of the image while looking for pattern redundancies. A fast FFT-based algorithm is proposed to compute the NLM with arbitrary shapes. The local combination of the different shapes relies on Stein’s ...

We consider left-invariant diffusion processes on DTI data by embedding the data into the space R o S of 3D positions and orientations. We then define and solve the diffusion equation in a moving frame of reference defined using left-invariant derivatives. The diffusion process is made adaptive to the data in order to do Perona-Malik-like edge preserving smoothing, which is necessary to handle ...

A new class of anisotropic diffusion models is proposed for image processing which can either be viewed as a novel kind of regularization of the classical Perona-Malik model or, as it is advocated by the authors, as a new independent model. The models are diffusive in nature and are characterized by the presence of both forward and backward regimes. In contrast to the Perona-Malik model, in the...

This paper describes a partial differential equation for denoising images. The proposed method is demonstrably superior to anisotropic diffusion (and it’s many variations) for denoising images that are approximately piecewise constant. The method relies on an equation that is the level-set equivalent of the anisotropic diffusion equation proposed by Perona and Malik [1]. This proposed equation ...

In this paper, we focus on a numerical method of a problem called the Perona-Malik inequality which we use for image denoising. This model is obtained as the limit of the Perona-Malik model and the p-Laplacian operator with p → ∞. In Atlas et al., (Nonlinear Anal. Real World Appl 18:57–68, 2014), the authors have proved the existence and uniqueness of the solution of the proposed model. However...

Existing integer-order Nonlinear Anisotropic Diffusion NAD used in noise suppressing will produce undesirable staircase effect or speckle effect. In this paper, we propose a new scheme, named Fractal-order Perona-Malik Diffusion FPMD , which replaces the integer-order derivative of the Perona-Malik PM Diffusion with the fractional-order derivative using G-L fractional derivative. FPMD, which is...

In this paper we investigate a family of partial di erential equations (PDEs) for image processing which can be regarded as isotropic nonlinear di usion with an additional factor on the right-hand side. The one-dimensional analogues to this lter class have been motivated as scaling limits of one-dimensional adaptive averaging schemes. In 2-D, mean curvature motion is one of the most prominent e...