When an image is viewed at decreasing resolutions in a Gaussian pyramid, information is lost gradually. Amid continuous intensity changes across scales, there are “quantum jumps” or “perceptual transitions” in our inner representation. In this paper, we study a representational paradigm called the perceptual scale-space which augments the Gaussian pyramid in traditional image scale-space theory...

To generate corresponding points for large size satellite, aerial or high resolution close-range image, it is always needed to downscale the original image to low resolution image via pyramid image generating to detect local features. So this paper studies the affection of the pyramid image on the repeatability performance of the state-of-the-art local feature detectors. For generating pyramid ...

This paper presented a simple and efficient algorithm for multi-focus image fusion, which used a multiresolution signal decomposition scheme called Laplacian pyramid method. The principle of Laplacian pyramid transform is introduced, and based on it the fusion strategy is described in detail. The method mainly composed of three steps. Firstly, the Laplacian pyramids of each source image are dec...

The deposition of a stack of amorphous a-Si:H and microcrystalline c-Si:H tandem thin film silicon solar cells micromorph requires at least twice the time used for a single junction a-Si:H cell. However, micromorph devices have a higher potential efficiency, thanks to the broader absorption spectrum of c-Si:H material. High efficiencies can only be achieved by mitigating the nanocracks in the c...

The key metric of surface texturing is the short-circuit current Jsc. It depends on front surface transmittance, light trapping and the spatial profiles of photogeneration G and collection efficiency hc. To take advantage of a one-dimensional profile of hc(z), where z is the shortest distance to the p–n junction, we determine G(z) via ray tracing. This permits rigorous optical assessment of com...

Picosecond time-resolved photoluminescence ~PL! spectroscopy has been used to investigate the optical properties of GaN pyramids overgrown on hexagonal-patterned GaN~0001! epilayers on sapphire and silicon substrates with AlN buffer layers. We found that: ~i! the release of the biaxial compressive strain in GaN pyramids on GaN/AlN/sapphire substrate led to a 7 meV redshift of the spectral peak ...

The three pyramids 6f Giza are situated a few miles southwest of Cairo, Egypt. The two largest pyramids stand within a few hundred meters of each other. They were originally of almost exactly the same height (145 meters), but the Great Pyramid of Cheops has a slightly larger square base (230 meters on a side) than the Second Pyramid of Chephren (215.5 meters on a side). A photograph of the pyra...

We have integrated magneto-optical traps (MOTs) into an atom chip by etching pyramids into a silicon wafer. These have been used to trap atoms on the chip, directly from a room temperature vapor of rubidium. This new atom trapping method provides a simple way to integrate several atom sources on the same chip. It represents a substantial advance in atom chip technology and offers new possibilit...