Video signal compression apparatus using noise reduction

• US 6,115,071 A
• Filed: 01/10/1995
• Issued: 09/05/2000
• Est. Priority Date: 10/13/1993
• Status: Expired due to Fees

• Current Assignee: Thomson Licensing SA (Vantiva SA)
• Original Assignee: Thomson Licensing SA (Vantiva SA)
• Inventors: Meehan, Paul Harquail, Casavant, Scott David, Hurst, Robert Norman Jr.
• Primary Examiner(s): LEE, RICHARD J
• Application Number:
  US08/371,039
• Time in Patent Office: 2,065 Days
• Field of Search: 348/404, 348/409, 348/415, 348/618, 348/620, 348/623, 348/405, 348/419
• US Class Current: 375/240.12
• CPC Class Codes: H04N 19/503 involving temporal prediction adaptive coding with adaptive selection between spatial and temporal predictive coding H04N19/107; adaptive coding with adaptive selection among a plurality of temporal predictive coding modes H04N19/109
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/82 involving filtering within a prediction loop
• CPC Class Codes: H04N 19/85 using pre-processing or post-processing specially adapted for video compression

Abstract

Noise reduction circuitry, in a video signal compression apparatus of the predictive DPCM compression type includes a simple nonlinear processing element within the DPCM loop to eliminate residues between predicted and real image signals, which are smaller than a predetermined value. Elimination of such residues dramatically reduces the amount of compressed data generated for signals including even modest amounts of noise.

Claims

1. Apparatus for compressing video signal in an MPEG like format using both intraframe coding and interframe coding, comprising:

a signal input terminal for applying said video signal;

a subtractor having a first input terminal coupled to said signal input terminal, a second input terminal and an output terminal for providing residues having a range of amplitude values between relatively larger amplitude values and relatively smaller amplitude values;

compression means including transform means, for compressing signal applied thereto, to generate compressed video signal using said both intraframe coding and interframe coding, wherein said residues are included in intraframe coded and interframe coded compressed output data by said compression means;

an image signal prediction means, including inverse transform means, responsive to said compressed video signal for generating intraframe and interframe predictive signals representing predictions of video signal being encoded, said predictive signals being coupled to the second input terminal of said subtractor; and

a nonlinear element, coupled between the output terminal of said subtractor and said compression means, for attenuating residues having said relatively larger amplitudes less than residues having said relatively smaller amplitudes.

2. Apparatus for compressing video signal in an MPEG like format using both intraframe coding and interframe coding, comprising:

a signal input terminal for applying said video signal;

a subtractor having a first input terminal coupled to said signal input terminal, a second input terminal and an output terminal for providing residues having a range of amplitude values between relatively larger amplitude values and relatively smaller amplitude values;

compression means including transform means, for compressing signal applied thereto, to generate compressed video signal using said both intraframe coding and interframe coding, wherein said residues are included in intraframe coded and interframe coded compressed output data by said compression means;

an image signal prediction means, including inverse transform means, responsive to said compressed video signal for generating intraframe and interframe predictive signals representing predictions of video signal being encoded, said predictive signals being coupled to the second input terminal of said subtractor; and

a nonlinear element, coupled between the output terminal of said subtractor and said compression means, for attenuating residues having said relatively larger amplitudes less than residues having said relatively smaller amplitudes wherein

said video signal occurs in frames, and said compression means compresses ones of said frames of said video signal by said intraframe coding and others of said frames by said interframe coding, and wherein said apparatus further includes means for conditioning said nonlinear element to process frames which are being intraframe coded differently than frames which are being interframe coded.

3. The apparatus set forth in claim 2 wherein said nonlinear element is a coring circuit.

4. Apparatus for compressing video signal in an MPEG compatible format using both intraframe coding and interframe coding, comprising:

a signal input terminal for applying said video signal;

a subtractor having a first input terminal coupled to said signal input terminal, a second input terminal and an output terminal for providing residues having a range of amplitude values between relatively larger amplitude values and relatively smaller amplitude values;

compression means including transform means, for compressing signal applied thereto, on a block by block basis, to generate compressed video signal using said both intraframe coding and interframe coding;

an image signal prediction means, including inverse transform means, responsive to said compressed video signal for generating, on a block by block basis, a predictive signal representing a prediction of video signal being encoded, said predictive signal being coupled to the second input terminal of said subtractor; and

a nonlinear element, coupled between the output terminal of said subtractor and said compression means, for attenuating residues having said relatively larger amplitudes less than residues having said relatively smaller amplitudes wherein said video signal occurs in frames and said compression means compresses ones of said frames by said intraframe coding and others of said frames by said interframe coding, and wherein said image signal prediction means is arranged to pass predicted image frames to the second input terminal of said subtractor during intervals of said intraframe coding, said apparatus further includes;

an adder having an output terminal, a first input terminal coupled to the second input terminal of said subtractor, and a second input terminal coupled to an output terminal of said nonlinear element;

a switch having first and second input terminals coupled to the output terminals of said nonlinear element and said adder respectively, and having an output terminal coupled to said compression means; and

means for conditioning said switch to pass signal applied to its first and second input terminals when frames are interframe and intraframe coded respectively.

5. Multiple mode video signal compression apparatus comprising:

a signal input terminal for applying video signal;

a subtractor having a first input terminal coupled to said signal input terminal, a second input and an output terminal;

transform means, having input and output terminals, for compressing said video signal on a block by block basis;

video signal prediction means, coupled to the output terminal of said transform means, and having an output terminal coupled to the second input terminal of said subtractor, and responsive to compressed said video signal for providing decompressed said video signal on a block by block basis;

a nonlinear element coupled between the input terminal of the transform means and the output terminal of said subtractor, wherein a transfer function of said nonlinear element is responsive to a compression mode of said video signal prediction means for processing signal provided at the output terminal of said subtractor differently for different modes; and

wherein said video signal occurs in frames, and respective frames are compressed according to a sequence of different compression processes, said apparatus further including means for conditioning said nonlinear element to function with differing transfer functions for said different compression processes.

6. Multiple mode video signal compression apparatus comprising:

a signal input terminal for applying video signal;

a subtractor having a first input terminal coupled to said signal input terminal, a second input and an output terminal;

transform means, having input and output terminals, for compressing said video signal on a block by block basis;

video signal prediction means, coupled to the output terminal of said transform means, and having an output terminal coupled to the second input terminal of said subtractor, and responsive to compressed said video signal for providing decompressed said video signal on a block by block basis;

a nonlinear element coupled between the input terminal of the transform means and the output terminal of said subtractor, wherein a transfer function of said nonlinear element is responsive to a compression mode of said video signal prediction means for processing signal provided at the output terminal of said subtractor differently for different modes; and

further including means for conditioning said nonlinear element to exhibit different transfer functions for different image blocks on a block by block basis.

7. Multiple mode video signal compression apparatus comprising:

a signal input terminal for applying video signal;

a subtractor having a first input terminal coupled to said signal input terminal, a second input and an output terminal;

transform means, having input and output terminals, for compressing said video signal on a block by block basis;

video signal prediction means, coupled to the output terminal of said transform means, and having an output terminal coupled to the second input terminal of said subtractor, and responsive to compressed said video signal for providing decompressed said video signal on a block by block basis;

a nonlinear element coupled between the input terminal of the transform means and the output terminal of said subtractor, wherein a transfer function of said nonlinear element is responsive to a compression mode of said video signal prediction means for processing signal provided at the output terminal of said subtractor differently for different modes; and

further including means responsive to the compression mode of said video signal prediction means for bypassing said nonlinear element transfer function.

8. Multiple mode video signal compression apparatus comprising:

a signal input terminal for applying video signal;

a subtractor having a first input terminal coupled to said signal input terminal, a second input and an output terminal;

transform means, having input and output terminals, for compressing said video signal on a block by block basis;

video signal prediction means, coupled to the output terminal of said transform means, and having an output terminal coupled to the second input terminal of said subtractor, and responsive to compressed said video signal for providing decompressed said video signal on a block by block basis;

a nonlinear element coupled between the input terminal of the transform means and the output terminal of said subtractor, wherein a transfer function of said nonlinear element is responsive to a compression mode of said video signal prediction means for processing signal provided at the output terminal of said subtractor differently for different modes; and

further including means for conditioning said non linear element to provide a linear transfer function in response to the compression mode of said video signal prediction means.

9. Apparatus for compressing video signal in multiple modes, comprising:

a signal input terminal for applying said video signal;

a subtractor having a first input terminal coupled to said signal input terminal, a second input terminal and an output terminal for providing residues having a range of amplitude values between relatively larger amplitude values and relatively smaller amplitude values;

motion compensated compression means including image signal prediction means, for generating, on a block by block basis, a predictive signal representing a prediction of video signal being compressed, said predictive signal being coupled to the second input terminal of said subtractor, wherein said residues in said multiple modes are formed into compressed output data by said motion compensated compression means;

a nonlinear element, coupled between the output terminal of said subtractor and said compression means, for attenuating residues having said relatively larger amplitudes less than residues having said relatively smaller amplitudes; and

means for applying only residues processed by said nonlinear element to said motion compensated compression means in a first compression mode, and for applying a combination of residues, and predictive signal from said motion compensated compression means, to said motion compensated compression means in a second compression mode.