A New Perspective in Shape from Shading from Sar Images
نویسندگان
چکیده
In this paper we propose a new technique for Shape from Shading (SfS) from Synthetic Aperture Radar (SAR) images based on fractals. In particular, the present paper shows that, introducing proper models both for surface and scattering mechanisms, it is possible to estimate with sufficient accuracy the underlying topography also with a very simple and low computational complexity inversion technique. Natural surfaces, which are here of concern, are modeled via fractal geometry, in particular a 2-D fractional Brownian motion (fBm) is used. The scattering mechanisms are described through solutions suitable for fractal surface models; in particular, the Small Perturbation Method (SPM) is used. Considering a simple SAR image model, an appropriate and extremely low-computational inversion technique is used to invert the direct model and estimate the underlying topography. The proposed SAR SfS method is tested and numerically evaluated using an actual SAR image.
منابع مشابه
Perspective Shape from Shading with Non-Lambertian Reflectance
In this work, we extend the applicability of perspective Shape from Shading to images incorporating non-Lambertian surfaces. To this end, we derive a new model inspired by the perspective model for Lambertian surfaces recently studied by Prados et al. and the Phong reflection model incorporating ambient, diffuse and specular components. Besides the detailed description of the modeling process, ...
متن کاملTerrain Modeling in Synthetic Aperture Radar Images Using Shape-from-Shading
In this paper we introduce a new approach for recovering shape-from-shading (SFS) from synthetic aperture radar (SAR) images of the terrain. Three contributions are proposed. Firstly, we show how the direction of surface normals is constrained by the geometry of the radar reflectivity cone. Second, we show how topographic features can be used as boundary constraints on the recovered surface nor...
متن کاملFast Marching Method for Shape from Shading under Perspective Projection
The fast marching method has recently been applied to the shape from shading problem for orthographic projection [4]. Unlike many previous researches, the method is stable and monotone, and offer a well posed solution to the shape from shading problem. In this paper, the method is extended to perspective projection using a model that accounts for the foreshortening effect of perspective project...
متن کاملA New Algorithm for Skin Lesion Border Detection in Dermoscopy Images
Background: With advances in medical imaging systems, digital dermoscopy has become one of the major imaging modalities in the analysis of skin lesions. Thus, automated segmentation or border detection has a great impact on the subsequent steps of skin cancer computer-aided diagnosis using demoscopy images. Since dermoscopy images suffer from artifacts such as shading and hair, there is a need ...
متن کامل"Perspective Shape from Shading" and Viscosity Solutions
This article proposes a solution of the Lambertian shape from shading (SFS) problem in the case of a pinhole camera model (performing a perspective projection). Our approach is based upon the notion of viscosity solutions of HamiltonJacobi equations. This approach allows us to naturally deal with nonsmooth solutions and provides a mathematical framework for proving correctness of our algorithms...
متن کامل