Apparatus for detecting movement in a television signal based on taking ratio of signal representing frame difference to signal representing sum of picture element differences

• US 4,639,767 A
• Filed: 09/07/1984
• Issued: 01/27/1987
• Est. Priority Date: 09/08/1983
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Suzuki, Norio
• Primary Examiner(s): Shepperd, John W.
• Application Number:
  US06/648,984
• Time in Patent Office: 872 Days
• Field of Search: 358/10, 358/21 R, 358/105
• US Class Current: 348/702
• CPC Class Codes: G06T 7/254 involving subtraction of images
• CPC Class Codes: H04N 5/144 Movement detection for video coding H04N19/503; analysis of motion in general G06T7/20

Abstract

A circuit for detecting the degree of movement in a television signal. The circuit is not affected by the direction in which picture elements move over the image area. Primarily, differences from frame to frame are detected as well as differences between picture elements of the same frame or picture element differences from frame to frame. The degree of image movement is determined by the ratio of the signal representing the frame difference and of a signal which represents the sum of the picture element differences. In further embodiments, image movement detection is based on detecting the brightness and/or chrominance components of the television signal and producing the frame difference signal based on these signal components or as a ratio of the frame difference signal and these signal components. The brightness (Y) signal can be extracted from the input television signal in a high frequency brightness signal extracting circuit. The frame difference signal is then based on the frame to frame difference of this high frequency Y signal.

Claims

1. A movement detection apparatus for detecting the degree of movement of an image which is represented by a composite television signal having a brightness signal component and a chrominance signal component, said apparatus comprising:

means for producing a first frame difference signal having a magnitude which is related to the difference between a present and previous brightness television signal, said frame difference means operating independently of the direction of movement of picture elements of said image;

means for producing a second frame difference signal having a magnitude which is related to the difference between a present and previous chrominance signal, said frame difference producing means operating independently of the direction of movement of picture elements of said image;

means for producing a first sum of picture element differences signal having a magnitude which is related to the differences between the value of a given picture element and adjacent picture elements based on said brightness signal component of said television signal, said first sum of picture element differences means operating independently of the direction of movement of picture elements of said image;

means for producing a second sum of picture element differences signal having a magnitude which is related to the differences between the value of a given picture element and adjacent picture elements based on the chrominance signal on said chrominance signal component of said television signal, said second sum of picture element differences means operating independently of the direction of movement of picture elements of said image; and

means for producing an output which is indicative of the degree of movement of said image in response to said first and second frame difference signals and said first and second picture element differences signals.

2. The apparatus of claim 1, further comprising a multiplier for scaling said second frame difference signal and an addition circuit for combining said first frame difference signal and said second frame difference signal scaled by said multiplier.

3. The apparatus of claim 2, further comprising a smoothing circuit for smoothing said output which is indicative of the degree of movement of said image.

4. The apparatus as in claim 1, wherein said composite television signal comprises a digitized television signal.

5. A movement detection apparatus for detecting the degree of movement of an image which is represented by a television signal, said apparatus comprising:

means for producing a frame difference signal having a magnitude which is related to the difference between a present and a previous television signal, said frame difference means operating independently of the direction of movement of picture elements of said image;

means for producing a sum of picture element differences signal having a magnitude which is related to the differences between the value of a given picture element and adjacent picture elements, said picture element differences means operating independently of the direction of movement of picture elements of said image; and

means for producing an output which is indicative of the degree of movement of said image in response to said frame difference signal and said picture element differences signal;

said means for producing a frame difference signal including a frame memory for storing therein previous frame data of said television signal and subtractor means for calculating a difference between said television signal and said previous frame data;

said picture element differences means comprising first means responsive to said television signal for producing a present frame sum of picture element differences signal, second means responsive to said previous frame data for producing a previous frame sum of picture element differences signal and a first addition circuit for adding said present and previous picture element differences signal, each said first and second means comprising;

an input;

a first subtraction circuit and a first line memory connected to said input, said line memory having an output connected to said first subtraction circuit, said first subtraction circuit having an output for calculating a difference between signals from said input and said first line memory;

a first absolute value circuit for generating an absolute value of said output of said first subtraction circuit;

a second line memory and a first addition circuit having respective inputs for receiving said absolute value, said second line memory having an output connected to another input of said first addition circuit, said first addition circuit having an output representing a difference between said inputs of said first addition circuit;

a delay circuit for delaying said output of said first addition circuit, said delayed output constituting said sum of picture element differences signal;

a first one sample delay and a second subtraction circuit having a respective first input connected to said first line memory, said second subtraction circuit having a second input connected to said first one sample delay and an output representing the difference between said first and second inputs of said second subtraction circuit;

a second absolute value circuit connected to said output of said second subtraction circuit; and

a second one sample delay and a second addition circuit having respective first inputs connected to said second absolute value circuit, said second one sample delay being further connected to a second input of said second addition circuit, said second addition circuit having an output, said output of said second addition circuit being effective for enabling calculation of said previous frame sum of picture element differences signal.

6. A movement detection apparatus for detecting the degree of movement of an image which is represented by a composite television signal having a brightness signal component and a chrominance signal component, said apparatus comprising:

means for producing a frame difference signal having an output which is related to the difference between a present and a previous television signal, said frame difference means operating independently of the direction of movement of picture elements of said image;

first means for filtering from said output of said frame difference signal said chrominance signal component to produce a filtered frame difference signal;

means for producing a sum of picture element differences signal having a magnitude which is related to the differences between the value of a given picture element and adjacent picture elements, said picture element differences means operating independently of the direction of movement of picture elements of said image;

second means for filtering from said picture element differences signal said chrominance signal component to produce a picture filtered element differences signal; and

meaans for producing an output indicative of the degree of movement of said image in response to said filtered frame difference signal and said filtered picture element differences signal;

said picture element differences means comprising a 2-line type comb filter which includes first and second series connected line memories;

first, second and third multipliers respectively connected to said television signal, said first line memory and said second line memory;

a first addition circuit for adding the outputs of said first, second and third multipliers;

said frame difference signal producing means comprising a frame memory for storing therein previous frame data of said television signal and subtractor means for calculating a difference between said television signal and said previous frame data;

an absolute value circuit connected to said first filtering means, and a delay circuit connected to said absolute value circuit, said delay circuit being connected to said means for producing an output indicative of the degree of movement of said image;

said picture element differences signal producing means further comprising a first one sample delay circuit connected to said comb filter;

a first subtraction circuit connected to said first one sample delay circuit and said comb filter;

an absolute value circuit connected to said first subtraction circuit;

a second one sample delay circuit connected to said absolute value circuit;

a second addition circuit connected to said second one sample delay circuit and to said absolute value circuit;

a second subtraction circuit connected to said television signal and to said first line memory;

a third subtraction circuit connected to said first line memory and to said second line memory;

a respective filtering means connected to each said second and third subtraction circuits;

a third addition circuit connected to said respective filtering means; and

a fourth addition circuit connected to said third addition circuit and to said second addition circuit, said fourth addition circuit being coupled to said means for producing an output indicative of the degree of movement of said image.

7. A movement detecting apparatus for detecting the degree of movement of an image which is represented by a composite television signal having a brightness signal component and a chrominance signal component, said apparatus comprising:

means for producing a frame difference signal having a magnitude which is related to the difference between a present and previous television signal;

means for obtaining a high frequency component signal from said composite television signal; and

means for producing an output which is indicative of the degree of movement of said image, said output being proportional to said frame difference signal and being scaled by said high frequency component signal;

said means for producing said frame difference signal including first means for producing a first frame difference signal based on said brightness signal component, a second means for producing a second frame difference signal based on said chrominance signal component, and an addition circuit for combining said first and second frame difference signals.

8. The apparatus of claim 7, further comprising a multiplier for scaling said second frame difference signal.

9. A movement detecting apparatus for detecting the degree of movement of an image which is represented by a composite television signal having a brightness signal component and a chrominance signal component, said apparatus comprising:

means for producing a frame difference signal having a magnitude which is related to the difference between a present and previous television signal;

means for obtaining a high frequency component signal from said composite television signal; and

means for producing an output which is indicative of the degree of movement of said image, said output being proportional to said frame difference signal and being scaled by said high frequency component signal;

said means for obtaining a high frequency component signal comprising a first one sample delay element;

a subtraction circuit connected to said first one sample delay circuit and to said television signal;

a two sample delay circuit connected to said subtraction circuit;

a first addition circuit connected to said two sample delay circuit and to said subtraction circuit;

an absolute value circuit connected to said first addition circuit;

a second one sample delay circuit connected to said absolute value circuit; and

a second addition circuit connected to said second one sample delay circuit and to said absolute value circuit.

10. A movement detection apparatus for detecting the degree of movement of an image which is represented by a composite television signal having a brightness signal component and a chrominance signal component, said apparatus comprising:

means for producing a first frame difference signal having a magnitude which is related to the difference between a present and previous brightness television signal, said frame difference means operating independently of the direction of movement of picture elements of said image;

means for producing a second frame difference signal having a magnitude which is related to the difference between a present and a previous chrominance signal, said frame difference producing means operating independently of the direction of movement of picture elements of said image;

means for producing a first sum of picture element differences signal having a magnitude which is related to the differences between the value of a given picture element and adjacent picture elements based on a present frame, said first sum of picture element differences means operating independently of the direction of movement of picture elements of said image;

means for producing a second sum of picture element differences signal having a magnitude which is related to the differences between the value of a given picture element and adjacent picture elements based on a previous frame, said second sum of picture element differences means operating independently of the direction of movement of picture elements of said image; and

means for producing an output which is indicative of the degree of movement of said image in response to said first and second frame difference signals and said first and second picture element differences signals.

11. The apparatus of claim 10, further comprising a multiplier for scaling said second frame difference signal and an addition circuit for combining said first frame difference signal and said second frame difference signal scaled by said multiplier.

12. The apparatus of claim 11, further comprising a smoothing circuit for smoothing said output which is indicative of the degree of movement of said image.