Image signal coding system

• US 5,949,489 A
• Filed: 07/31/1998
• Issued: 09/07/1999
• Est. Priority Date: 10/22/1991
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Yamada, Yoshihisa, Nishikawa, Hirofumi, Asai, Kohtaro, Murakami, Tokumichi
• Primary Examiner(s): LIN, BRYAN T
• Application Number:
  US09/126,762
• Time in Patent Office: 403 Days
• Field of Search: 348/384, 348/390, 348/400, 348/401, 348/402, 348/409, 348/411, 348/412, 348/413, 348/414, 348/415, 348/416, 382/232, 382/236, 382/238
• US Class Current: 348/412.1
• CPC Class Codes: H04N 19/105 Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction
• CPC Class Codes: H04N 19/112 according to a given display mode, e.g. for interlaced or progressive display mode
• CPC Class Codes: H04N 19/119 Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks
• CPC Class Codes: H04N 19/124 Quantisation
• CPC Class Codes: H04N 19/132 Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking
• CPC Class Codes: H04N 19/137 Motion inside a coding unit, e.g. average field, frame or block difference
• CPC Class Codes: H04N 19/14 Coding unit complexity, e.g. amount of activity or edge presence estimation H04N19/146 takes precedence
• CPC Class Codes: H04N 19/152 by measuring the fullness of the transmission buffer
• CPC Class Codes: H04N 19/16 for a given display mode, e.g. for interlaced or progressive display mode
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/577 Motion compensation with bidirectional frame interpolation, i.e. using B-pictures
• CPC Class Codes: H04N 19/61 in combination with predictive coding

Abstract

An adaptive blocking coding system selects an effective blocking of an input image signal to be encoded in accordance with the correlation between fields, even if motion is detected between the fields. The blocking patterns include an individual field blocking, a non-interlace blocking, a split blocking and an inverted split blocking. Further, the coding system searches for motion from both odd and even fields of a frame for producing a motion compensated prediction signal in order to provide high-efficient coding.

Claims

1. A video signal conversion system for converting a first motion video signal representative of sequential video images including first and second video images into a second motion video signal comprising:

a field memory for storing information representative of a first video image as plural image fields;

a predictive signal generator, operatively connected to said field memory, and supplying plural predictive signals from said plural image fields stored in said field memory;

an interpolator, operatively connected to said field memory, and interpolating at least some of the plurality of predictive signals and for generating an interpolated predictive signal which is different from any of the plurality of predictive signals supplied by said predictive signal generator;

a selector, receiving the plural predictive signals and the interpolated predictive signal, and selecting a predictive signal from the plurality of predictive signals and the interpolated predictive signal;

wherein a signal representative of the second video image of the first motion video signal is assembled from a predictive error signal developed from a difference between said first video image and the second video image; and

a combiner, operatively connected to said field memory, and combining said predictive error signal with said interpolated predictive signal produced by said interpolator.

2. The video signal conversion system of claim 1 wherein said combiner includes an adder, said adder adding said predictive error signal and said interpolated signal produced by said interpolator and supplying the output thereof to said field memory.

3. The video signal conversion system of claim 2 further comprising:

a subtracter, operatively connected to said selector, and subtracting one of said plural predictive signals including said interpolated predictive signal from a signal representative of the second video image of said first motion video signal to form the predictive error signal;

an encoder, operatively connected to said subtracter, and encoding said predictive error signal to form an encoded predictive error signal; and

means, operatively connected to said encoder, for decoding the encoded predictive error signal for supply to said combiner.

4. The video signal conversion system of claim 2 further comprising:

means, operatively connected to said combiner, for decoding an encoded predictive error signal for supply to said combiner.

5. The video signal conversion system of claim 2 wherein the interpolator produces the interpolated predictive signal by computing the arithmetic mean of at least some of the plural predictive signals.

6. The video signal conversion system of claim 5 wherein said arithmetic mean is a weighted arithmetic mean.

7. The video signal conversion system of claim 1, wherein said first motion video signal is an original video image.

8. The video signal conversion system of claim 1, wherein said first motion video signal is encoded image data of an original video image.

9. A video signal conversion system for converting a first motion video signal representative of sequential video images including first and second video images into a second motion video signal comprising:

a field memory for storing information representative of a first video image as plural image fields;

a predictive signal generator, operatively connected to said field memory, and supplying plural predictive signals from said plural image fields stored in said field memory;

an interpolator, operatively connected to said field memory, and interpolating at least some of the plurality of predictive signals and for generating an interpolated predictive signal which is different from any of the plurality of predictive signals supplied by said predictive signal generator;

wherein a signal representative of the second video image of the first motion video signal is assembled from a predictive error signal developed from a difference between said first video image and the second video image; and

a combiner, operatively connected to said field memory, and combining said predictive error signal with said interpolated predictive signal produced by said interpolator.

10. The video signal conversion system of claim 9 wherein said combiner includes an adder, said adder adding said predictive error signal and said interpolated signal produced by said interpolator and supplying the output thereof to said field memory.

11. The video signal conversion system of claim 10 further comprising:

a subtracter, operatively connected to said interpolator, and subtracting one of said plural predictive signals including said interpolated predictive signal from a signal representative of the second video image to form the predictive error signal;

an encoder, operatively connected to said subtracter, and encoding said predictive error signal to form an encoded predictive error signal; and

means, operatively connected to said encoder, for decoding the encoded predictive error signal for supply to said combiner.

12. The video conversion system of claim 10 further comprising:

means, operatively connected to said combiner, for decoding an encoded predictive error signal for supply to said adder.

13. The video signal conversion system of claim 10 further comprising:

a selector, operatively connected to said predictive signal generator for receiving the predictive signals and the interpolated predictive signal and for selecting a predictive signal from the plurality of predictive signals and the interpolated predictive signal.

14. The video signal conversion system of claim 9 wherein the interpolator produces the interpolated predictive signal by computing the arithmetic mean of at least some of the plural predictive signals.

15. The video signal conversion system of claim 14 wherein said arithmetic mean is a weighted arithmetic mean.

16. The video signal conversion system of claim 9, wherein said first motion video signal is an original video image.

17. The video signal conversion system of claim 9, wherein said first motion video signal is encoded image data of an original video image.

18. A video signal conversion system for converting a first motion video signal representative of sequential video images including first and second video images into a second motion video signal comprising:

a field memory for storing information representative of a first video image as plural image fields;

a predictive signal generator, operatively connected to said field memory, and supplying plural predictive signals from said plural image fields stored in said field memory;

an interpolator, operatively connected to said field memory, and interpolating at least some of the plurality of predictive signals and for generating an interpolated predictive signal which is different from any of the plurality of predictive signals supplied by said predictive signal generator;

wherein a signal representative of the second video image of the first motion video signal is assembled from a predictive error signal developed from a difference between said first video image and the second video image;

means for decoding the predictive error signal;

a combiner, operatively connected to said field memory and combining said predictive error signal with said interpolated predictive signal produced by said interpolator;

means for generating a reproduced video signal based on the predictive error signal; and

means for outputting a reproduced video signal.

19. The video signal conversion system of claim 18, wherein said first motion video signal is an original video image.

20. The video signal conversion system of claim 18, wherein said first motion video signal is encoded image data of an original video image.