Journal Article10.1364/JOSAA.10.000561
Entropy-based depth from focus
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TL;DR: In this article, the entropy loss in a linear filter was used to solve the depth-from-focus problem, which leads to a relatively simple solution whose variance is equal to or less than that from a regression approach.
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Abstract: The two-image depth-from-focus problem is reconsidered in terms of entropy loss in a linear filter. It is shown that this formulation leads to a relatively simple solution whose variance is equal to or less than that from a regression approach. The formulation is appropriate even when the point-spread function of the optical system is not well suited to a low-order regression fit or when both images used contain some degree of defocusing with distance.
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Citations
Depth from defocus vs. stereo: how different really are they?
Yoav Y. Schechner,Nahum Kiryati +1 more
- 16 Aug 1998
TL;DR: The effect of noise in different spatial frequencies is analyzed, and the optimal changes of the focus settings in DFD are derived, elucidate the limitations of methods based on depth of field and provide a foundation for fair performance comparison between DFF/DFD and shape from stereo (or motion) algorithms.
Depth from Defocus vs. Stereo: How Different Really Are They?
Yoav Y. Schechner,Nahum Kiryati +1 more
TL;DR: In this article, the effect of noise in different spatial frequencies, and derive the optimal changes of the focus settings in DFD are analyzed and compared with shape from stereo (or motion) algorithms.
212
Depth from focus with your mobile phone
Supasorn Suwajanakorn,Carlos Hernández,Steven M. Seitz +2 more
- 07 Jun 2015
TL;DR: This work introduces the first depth from focus (DfF) method capable of handling images from mobile phones and other hand-held cameras, solving a novel uncalibrated DfF problem and aligning the frames to account for scene parallax.
Simple range cameras based on focal error
TL;DR: Research is described on two imaging range sensors that use defocus to estimate range and one technique is completely passive and provides dense range measurements in textured areas with an rms error of 2.5%.
115
Telecentric Optics for Computational Vision
Masahiro Watanabe,Shree K. Nayar +1 more
- 15 Apr 1996
TL;DR: It is shown that magnification of a conventional lens can be made invariant to defocus by simply adding an aperture at an analytically derived location, and the resulting optical configuration is called telecentric.
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