Pulldown field detector
First Claim
1. A method for detecting a pull-down field in a stream of video fields, the method comprising:
- generating an array of variance indications, each of the variance indications representing a degree of variance between two video fields in the stream of video fields; and
comparing the array of variance indications to a predetermined pattern to detect a pull-down video field in the stream of video fields.
6 Assignments
0 Petitions
Accused Products
Abstract
A system and method for detecting the presence and location of pull-down fields in a video field stream. Various aspects of the present invention may comprise method steps and circuit structure for generating an array of variance indications, each of which represents a degree of variance between two video fields in the video field stream. Various aspects may comprise comparing the array of variance indications to a pattern to detect a pull-down field in the video field stream. Various aspects may comprise comparing corresponding portions of video fields and generating a histogram of differences between the corresponding portions. Various aspects may comprise generating an indication of variance of the histogram and analyzing the indication of variance. Various aspects may comprise analyzing an array of such indications of variance and may comprise comparing the array of such indications to a pattern or plurality of patterns.
12 Citations
31 Claims
-
1. A method for detecting a pull-down field in a stream of video fields, the method comprising:
-
generating an array of variance indications, each of the variance indications representing a degree of variance between two video fields in the stream of video fields; and
comparing the array of variance indications to a predetermined pattern to detect a pull-down video field in the stream of video fields. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 18)
-
-
11. A method for detecting a pull-down field in a stream of video fields, the stream of video fields having, sequentially, a first video field, a second video field, a third video field, and a fourth video field, the method comprising:
-
comparing corresponding portions of the first video field and the third video field;
generating a first histogram of differences of the compared portions of the first video field and the third video field;
generating a first indication of variance of the first histogram; and
determining whether the third video field is a pull-down field by comparing the first indication of variance to a first value. - View Dependent Claims (12, 13, 14, 15, 16, 17)
-
-
19. A system for detecting pull-down fields in a video field stream, the system comprising:
-
a first logic circuit that compares two video fields and outputs difference values resulting from the comparison;
a second logic circuit coupled to the first logic circuit that receives the difference values from the first logic circuit and outputs an indication of variance of the difference values;
a third logic circuit coupled to the second logic circuit that receives the indication of variance from the second logic circuit and outputs the indication of variance in an array of variance indications; and
a fourth logic circuit coupled to the third logic circuit that receives the array of variance indications, compares the array of variance indications to a predetermined pattern, and outputs an indication of whether the array of variance indications and the predetermined pattern correspond. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
-
Specification