A method is proposed to enhance vascular structures within the framework of scale space theory. We combine a smooth vessel filter which is based on a geometrical analysis of the Hessian's eigensystem, with a non-linear anisotropic diffusion scheme. The amount and orientation of diffusion depend on the local vessel likeliness. Vessel enhancing diffusion (VED) is applied to patient and phantom da...

Based on a local spatial/frequency representation, the spectral histogram of an image is defined as the marginal distribution of responses from a bank of filters. We propose the spectral histogram as a quantitative definition for textons. The spectral histogram model avoids rectification and spatial pooling, two commonly assumed stages in texture discrimination models. By matching spectral hist...

Image restoration has been an active research area. Different formulations are effective in high quality recovery. Partial Differential Equations (PDEs) have become an important tool in image processing and analysis. One of the earliest models based on PDEs is Perona-Malik model that is a kind of anisotropic diffusion (ANDI) filter. Anisotropic diffusion filter has become a valuable tool in dif...

Denoising algorithms based on gradient dependent energy functionals, such as Perona-Malik and total variation denoising, modify images towards piecewise constant functions. Although edge sharpness and location is well preserved, important information, encoded in image features like textures or certain details, is often compromised in the process of denoising. We propose a mechanism that better ...

A multiresolution segmentation approach for color images is presented. The scale space is generated using the Perona-Malik diffusion approach and the watershed algorithm is employed to produce the regions in each scale. The dynamics of contours and the relative entropy of color regions distribution are estimated as region dissimilarity features, and combined using a fuzzy rule based system. A m...

A multi-resolution segmentation approach for color images is proposed. The scale space is generated using the Perona-Malik diffusion approach and the watershed algorithm is employed to produce the regions in each scale. The dynamics of contours and the relative entropy of color regions distribution are estimated as region dissimilarity features across the scale-space stack, and combined using a...

Multiscale methods have proved to be successful tools in image denoising, edge enhancement and shape recovery. They are based on the numerical solution of a nonlinear diffusion problem where a noisy or damaged image which has to be smoothed or restorated is considered as initial data. Here a novel approach is presented which will soon be capable to ensure real time performance of these methods....

We propose a modified Perona-Malik diffusion (PMD) filter to enhance a coronary plaque boundary by considering the conditions peculiar to an intravascular ultrasound (IVUS) image. The IVUS image is commonly used for a diagnosis of acute coronary syndrome (ACS). The IVUS image is however very grainy due to heavy speckle noise. When the normal PMD filter is applied for speckle noise reduction in ...

We consider a class of nonconvex functionals of the gradient in one dimension, which we regularize with a second order derivative term. After a proper rescaling, suggested by the associated dynamical problems, we show that the sequence {Fν} of regularized functionals Γ-converges, as ν → 0+, to a particular class of free-discontinuity functionals F , concentrated on SBV functions with finite ene...

The widely used denoising algorithms based on nonlinear diffusion, such as Perona-Malik and total variation denoising, modify images toward piecewise constant functions. Though edge sharpness and location is well preserved, important information, encoded in image features like textures or small details, is often lost in the process. We suggest a simple way to better preserve textures, small det...