Name
Abstract | ||
|---|---|---|
Traditional shape from defocus has been based on modeling the defocusing process through a normalized point spread function
(PSF). Here we show that, in the general case, the normalization factor will depend on the depth map, what precludes shape
estimation. If the camera is focused at far distances, however, such dependence can be neglected and an unnormalized PSF can
be employed. We thus reformulate Pentland’s shape from defocus approach using unnormalized gaussians, and prove that, under
certain assumptions, such model allows the estimation of a dense depth map from a single input image. Moreover, by using unnormalized
Gabor functions as a generalization of the unnormalized-gaussian PSF, we are able to approximate any signal as resulting from
a series of local, frequency-dependent defocusing processes, to which the modified Pentland’s approach also applies. Such
approximation proves suitable for shading images, and has allowed us to obtain good shape-from-shading estimates essentially
through a shape-from-defocus approach, without resorting to the reflectance map concept.
|
Year | DOI | Venue |
|---|---|---|
2008 | 10.1007/978-3-540-89646-3_49 | International Symposium on Visual Computing |
Keywords | Field | DocType |
shape estimation,unnormalized-gaussian psf,traditional shape,depth map,dense depth map,unnormalized psf,reflectance map concept,unnormalized gaussians,shape-from-defocus approach,unnormalized gabor function,shape from shading,point spread function | Computer vision,Normalization (statistics),Computer science,Artificial intelligence,Depth map,Point spread function,Reflectivity,Shading | Conference |
Volume | ISSN | Citations |
5359 | 0302-9743 | 0 |
PageRank | References | Authors |
0.34 | 8 | 2 |
Name | Order | Citations | PageRank |
|---|---|---|---|
| José R. A. Torreão | 1 | 59 | 10.18 |
| João L. Fernandes | 2 | 16 | 3.80 |