We present a novel algorithm to reconstruct the geometry and photometry of a scene with occlusions from a collection of defocused images. The presence of a finite lens aperture allows us to recover portions of the scene that would be occluded in a pin-hole projection, thus “uncovering” the occlusion. We estimate the shape of each object (a surface, including the occluding boundaries), and its r...

Darkfield imaging can achieve in situ observation of marine plankton with unique advantages high-resolution, high-contrast and colorful for species identification, size measurement abundance estimation. However, existing underwater darkfield imagers have very shallow depth-of-field, leading to inefficient seawater sampling observation. We develop a data-driven method that algorithmically refocu...

0167-8655/$ see front matter 2009 Elsevier B.V. A doi:10.1016/j.patrec.2009.11.016 * Corresponding author. Address: School of Com Engineering, Shanghai University, Shanghai 200072, C fax: +86 21 56331194. E-mail address: [email protected] (Z. Liu). In this paper, we propose an automatic segmentation approach to extract focused objects from images with low depth of field (DOF). A focus ene...

The Point Spread Function (PSF) of an image forming optical system is determined by the parameters of the optical system and the distance or depth of the object being imaged. In this paper we consider the depth information in the PSF of the optical system determined by paraxial wave optics under quasi-monochromatic incoherent illumination. The spread parameter of a PSF is deened as the standard...

A conventional camera with small size pixels may capture images with defocused blurred regions. Blurring, as a lowpass filter, attenuates or drops details of the captured image. This fact makes deblurring as an ill-posed problem. Coded aperture photography can decrease destructive effects of blurring in defocused images. Hence, in this case, aperture patterns are designed or evaluated based on ...

We demonstrate an approach for improving the image quality for a projector system with a shape-programmable pupil, which could be generated by an illumination modular in which a digital micromirror device is embedded. Essentially, the shaped pupil from the illumination modulator is developed with a dynamically programmable approach to provide aberration compensation for the projection system. B...

Depth from defocus (DFD) involves estimating the relative blur between a pair of defocused images of a scene captured with di erent lens settings. When a priori information about the scene is available, it is possible to estimate the depth even from a single image. However, experimental studies indicate that the depth estimate improves with multiple observations. In this paper, we provide a mat...

We used diffraction modulation transfer functions and model eyes to predict the effect of defocus on the contrast sensitivity function (CSF) and compared these predictions with previously published experimental data. Using the principle that optically induced changes in the modulation transfer function should be paralleled by identical changes in the CSF, we used the modulation transfer functio...

PURPOSE To examine the effect of misalignment (decentration and tilt) of intraocular lenses (IOLs) on retinal image quality using a water-immersed model eye with corneal spherical aberration adjusted to the values found in normal human eyes (spherical aberration 0.25 μm; pupil diameter 6 mm). METHODS Three types of IOL holders were prepared. The first was without decentration or tilt, the sec...