Search results
Results from the WOW.Com Content Network
Pyramid, or pyramid representation, is a type of multi-scale signal representation developed by the computer vision, image processing and signal processing communities, in which a signal or an image is subject to repeated smoothing and subsampling. Pyramid representation is a predecessor to scale-space representation and multiresolution analysis.
It was introduced in this context in 1988/89 by Stephane Mallat and Yves Meyer and has predecessors in the microlocal analysis in the theory of differential equations (the ironing method) and the pyramid methods of image processing as introduced in 1981/83 by Peter J. Burt, Edward H. Adelson and James L. Crowley.
A rotation of the vector through an angle θ in counterclockwise direction is given by the rotation matrix: = ( ), which can be viewed either as an active transformation or a passive transformation (where the above matrix will be inverted), as described below.
If a camera flash goes on for only part of the time of the exposure, the illumination of the flash may only be present for some rows of pixels in a given frame. For example, the top 1/3 of the picture may be brightly lit by a flash, while the bottom 2/3 of the picture is dark and unlit, as the flash was off by the time that part of the CMOS was ...
Scholars have spent decades delving into what techniques the builders used to position the pyramid’s so they face almost absolute north, south, east & west. Giza pyramid’s nearly perfect ...
Flash photolysis is a pump-probe laboratory technique, in which a sample is first excited by a strong pulse of light from a pulsed laser of nanosecond, picosecond, or femtosecond pulse width or by another short-pulse light source such as a flash lamp.
Depending on the frequency of flash, the element appears motionless or rotating in reverse direction. The stroboscopic effect is a visual phenomenon caused by aliasing that occurs when continuous rotational or other cyclic motion is represented by a series of short or instantaneous samples (as opposed to a continuous view) at a sampling rate ...
The concept was using a rotating diode rectifier on the shaft of the synchronous machine to harvest induced alternating voltages and rectify them to feed the generator field winding. [3] [4] [5] Brushless excitation has been historically lacking the fast flux de-regulation, which has been a major drawback. However, new solutions have emerged. [6]