Patent · US Expired

Histogram operating unit for video signals

US6038341A · kind A · utility

8Cited by
5References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 4, 1998
Grant dateMar 14, 2000
Priority date
Expiry dateMar 4, 2018

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N5/20
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A histogram operating unit comprises: histogram generator which receives input video signals, and creates a histogram of input video signals, a first limiter for receiving a histogram generated by the histogram generator and an externally set first limit level, and restricting the frequency of the histogram created by the histogram generator to within a specified level, and outputting a restricted histogram, a first totaling circuit for calculating the number of samples of video signals produced by the first limiter, second totaling circuit for calculating the number of samples of the input video signals, a first subtractor for subtracting the output of the first totaling circuit from the output of the second totaling circuit, and a corrected histogram generator which receives the output of the first limiter and the output of the first subtractor, and creates the corrected histogram.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.