US 5,396,284 A · Motion detection system

Abstract

A system for detecting motion in a video image is provided wherein the video image is processed into a statistical array in which the array elements are derived from overlapping portions of the image. The elements of the statistical array are compared with corresponding array elements derived from an earlier image. The overlapping nature of the statistical array elements allows any detected changes in the image to be correlated with a portion of the image that is smaller than the area from which the statistical quantities are derived. Such spatial correlation of detected image changes is accomplished by thresholding and/or Boolean comparisons among the elements of the statistical array. A motion detection system in accordance with this invention can be used with a video multiplexing system so that motion can be detected at a plurality of remote locations.

Claims21

Dependent claims

An apparatus for detecting motion within video images comprising:

(a) statistical means for deriving a first plurality of statistical values including a first value representative of a first portion of a video image, and a second value representative of a second portion of the video image, said second portion of the video image at least partially overlapping said first portion;
(b) storage means for storing a second plurality of statistical values derived from a previous video image;
(c) comparison means for comparing spatially corresponding statistical values of said first and second pluralities of statistical values and for signaling a difference determined between any of the spatially corresponding statistical values;
and
(d) motion indicating means responsive to the difference signal for indicating the detection of motion.

2 more elements

An apparatus for detecting motion within video images, the apparatus comprising:

(a) sampling means for sampling scan lines of a video image and for producing sample values representative of segments of each of said scan lines;
(b) initiating means for initiating said sampling means to produce a first plurality of sample values representative of a first plurality of the scan line segments;
(c) delay means for selectively delaying said initiating means and causing said sampling means to produce a second plurality of sample values representative of a second plurality of the scan line segments, said second plurality of scan line segments being displaced relative to said first plurality of segments by an amount less than the length of one of said segments;
(d) storage means for storing said first and second plurality of sample values;
(e) comparison means for comparing said first and second plurality of sample values with spatially corresponding first and second pluralities of stored sample values derived from a previous video image;
and
(f) motion indicating means responsive to said comparison means for indicating the detection of motion.

4 more elements

A method for detecting motion comprising the steps of:

receiving a video image;
generating a plurality of statistical values from said video image, said plurality of statistical values comprising:
a) a first statistical value corresponding to a first spatial region within the video image, and
b) a second statistical value corresponding to a second spatial region within the video image, said second spatial region at least partially overlapping the first spatial region;
comparing each of said first and second statistical values to spatially corresponding stored statistical values generated from a previous video image;
and
signalling that motion has been detected when a difference is recognized between said statistical values and said stored values.

4 more elements

Dependencies are inferred from the claim text.

Motion detection system

Life of this patent

Motion detection system

Life of this patent

Abstract

Claims21