Understanding the maximal enhancement of solar absorption in semiconductor materials by light trapping promises the development of affordable solar cells. However, the conventional Lambertian limit is only valid for idealized material systems with weak absorption, and cannot hold for the typical semiconductor materials used in solar cells due to the substantial absorption of these materials. He...

A divide-and-conquer strategy in shape from shading problem under fully perspective condition is proposed for the information recovery of book surfaces. The whole recovery process is composed of three sequential steps : preprocessing, apparent shape recovery, and ortho-image generation. Pure shade images are extracted at preprocessing step by introducing phenomenological model of interre ection...

Surveillance systems are commonly used to monitor and track individuals in a cluttered environment. Face images that are captured using such a system often suffer from poor resolution and consequently degrade the performance of any face recognition system which may be applied to these images. Super-resolution (SR) is one avenue for overcoming this limitation, however, many existing SR technique...

In this paper, we describe a method for correcting underexposed images by recovering the Lambertian diffuse component in the scene. The method makes use of an implicit mapping between the objects in the scene and a unit sphere. As a result of this treatment, the scene radiance function can be represented by a polar function on the unit sphere. We pose the problem of recovering the scene radianc...

A state-space approach to H2 model reduction of stable systems is pursued, using techniques from global rational optimization, and aimed at finding global optima. First, a concentrated version of the H2 criterion is derived, by optimizing analytically with respect to a subset of parameters. Next, a bound is developed, which is shown to be sharp for reduction to models of order 1. The choice of ...

background: in myocardial perfusion spect imaging, images are degraded by photon attenuation, the distance-dependent collimator, detector response and photons scatter. filters greatly affect quality of nuclear medicine images materials and methods: a phantom simulating heart left ventricle was built. about 1mci of 99mtc was injected into the phantom. images were taken from this phantom. some fi...