The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 19, 2002
Filed:
Jul. 02, 1999
Radu Alexandru, Cheshire, CT (US);
Aloka Co., Ltd., , JP;
Abstract
An apparatus ( ) for the real-time calculation of local variance in an array of digital signals includes a first squaring device ( ) arranged to receive an input signal, the input signal being one of a plurality of signals within a window defined in the array. The first squaring device ( ) squares the value indicated by the input signal and provides a signal indicative of the squared value to a first recursive sum device ( ). The first recursive sum device ( ) uses a recursive sum method to calculate the sum of the squares of a plurality of values indicated by the plurality of digital signals. The input signal is also received by a second recursive sum device ( ). The second recursive sum device ( ) uses a recursive sum method to calculate the sum of the plurality of values. The second recursive sum device ( ) outputs a signal indicative of this sum to a second squaring device ( ), which, in turn, provides a signal to a first dividing device ( ). The signal output from the first dividing device ( ) is indicative of the square of the sum of the plurality of values in the window, divided by the number of digital signals in the window. In the first subtracting device ( ), this value is subtracted from the value indicated by the signal from the first recursive sum device ( ). Finally, in the second dividing device ( ), the value indicated by the signal from the first subtracting device ( ) is divided by the number of digital signals in the window. The resulting value is the variance for the plurality of values. A signal indicative of this value is output from the second dividing device ( ).