Abstract:
PROBLEM TO BE SOLVED: To provide a method for controlling a load current even when a current ripple significantly varies. SOLUTION: The method includes: (A) a step of setting a threshold value of a comparator in correspondence to a reference current value for a load; (B) a step of measuring a first time interval from an active ON state of an ON phase of a power stage to a point of time when the load current reaches the reference current value; and (C) a step of continuously maintaining the power stage in the ON phase. Step (C) is performed while the power stage is further maintained in the predictive ON state for an additional time interval. The additional time interval is determined based on an average value of the first time interval and a time interval of the active ON state measured during a past PWM (pulse width modulation) cycle. COPYRIGHT: (C)2010,JPO&INPIT
Abstract:
A method of filtering noise of digital pictures comprises selecting a first set of pixels (WORKING_WINDOW) constituted by the union of a pixel of the current picture to be filtered (P) and of a second set of pixels temporally and spatially near (PIXEL_NEAR) to said pixel, calculating a certain number (N) of extended sums (SUMkj) of values assumed by as many pre-established weight functions of the intensity of a selected video component (kj) on the first set of pixels (WORKING_WINDOW). The pixels of the second set of pixels near (PIXEL_NEAR) can belong to the current picture or to a preceding picture. Several noise filters for digital pictures implementing the method of the invention are also presented.