Image signal coding system

• US 6,002,439 A
• Filed: 05/27/1999
• Issued: 12/14/1999
• 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:
  US09/320,726
• Time in Patent Office: 201 Days
• Field of Search: 348/384, 348/390, 348/400, 348/401, 348/402, 348/403, 348/404, 348/405, 348/409, 348/415, 348/420, 348/416, 382/232, 382/233, 382/236, 382/238
• US Class Current: 375/240.12
• 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 between a first motion video signal representative of sequential video images including first and second video images and a second motion video signal comprising:

a decoder detecting the scanning sequence of transform coefficients used in transform coding, and decoding the transform coefficients to produce information representative of the first and second video images;

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

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

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

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

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

2. The video signal conversion system of claim 1 wherein the scanning sequence used in transform coding the transform coefficients is determined based on coding efficiency.

3. The video signal conversion system of claim 1 wherein the conversion system converts from the first motion video signal to the second video signal.

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

5. The video signal conversion system of claim 1 further comprising:

a subtracter, operatively connected to said interpolator, and subtracting one of the plural predictive signals including the interpolative 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 the 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.

6. The video signal conversion system of claim 1 wherein said interpolator produces the interpolated predictive signal by computing the arithmetic mean of at least some of the plural predictive signals.

7. The video signal conversion system of claim 1 further comprising:

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

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

a decoder detecting the scanning sequence of transform coefficients used in transform coding, and decoding the transform coefficients to produce information representative of the first motion video signal including the first and second video images;

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 the plural image fields stored in said field memory;

an interpolator, operatively connected to said field memory, interpolating at least some of the plurality of predictive signals and 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 said 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;

a combiner, operatively connected to said field memory and combining the predictive error signal with the 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.

9. The video signal conversion system of claim 8 wherein the scanning sequence used in transform coding the transform coefficients is determined based on coding efficiency.

10. The video signal conversion system of claim 8 wherein the conversion system converts from the first motion video signal to the second video signal.

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

a decoder detecting the scanning sequence of transform coefficients used in transform coding, and decoding the transform coefficients to produce information representative of the first and second video images;

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

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

wherein a signal representative of the second video image is assembled from a predictive error signal output from said decoder and developed from a difference between the first video image and the second video image and is composed into blocks;

a block deformer, operatively connected to said decoder and decomposing a blocked predictive error signal representative of the second video image into the predictive error signal to remove the blocking therefrom; and

a combiner, operatively connected to said block deformer and combining the predictive error signal from said block deformer with the predictive signal obtained from said predictive signal generator.

12. The video signal conversion system of claim 11 wherein the scanning sequence used in transform coding the transform coefficients is determined based on coding efficiency.

13. The video signal conversion system of claim 11 wherein the conversion system converts from the first motion video signal to the second video signal.

14. The video signal conversion system of claim 11 wherein said field memory stores plural image fields and the predictive image signal supplies plural predictive signals from said plural image fields, said predictive signal generator including,

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, and

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.

15. The video signal conversion system of claim 14 wherein said combiner includes an adder, said adder adding the predictive error signal and the interpolated signal produced by said interpolator and supplying the output thereof to said field memory.

16. The video signal conversion system of claim 14 further comprising:

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

said decoder being operatively connected to said encoder, for decoding the encoded error signal for supply to said combiner.

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

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

a decoder detecting the scanning sequence of the transform coefficient used in transform coding, and decoding the transform coefficients to produce information representative of the first and second video images;

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

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

an interpolator, operatively connected to said predictive signal generator, and interpolating at least some of the plural 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 block deformer decomposing the blocked signal representative of the second video image into the predictive error signal to remove the blocking therefrom;

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

a combiner, operatively connected to said block deformer memory, and combining the predictive error signal with a predictive signal produced by said interpolator or said predictive signal generator.

19. The video signal conversion system of claim 18 wherein the scanning sequence used in transform coding the transform coefficients is determined based on coding efficiency.

20. The video signal conversion system of claim 18 wherein the conversion system converts from the first motion video signal to the second video signal.

21. The video signal conversion system of claim 18 wherein said combiner includes an adder, said adder adding the predictive error signal and the predictive error signal produced by said interpolator and supplying the output thereof to said field memory.

22. The video signal conversion system of claim 18 further comprising:

a subtracter, operatively connected to said interpolator, and subtracting one of the plural predictive signals including the interpolative 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 the 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.

23. The video signal conversion system of claim 18 wherein the interpolator produces the interpolated predictive signal by computing the arithmetic mean of at least some of the plural predictive signals.

24. The video signal conversion system of claim 18 further comprising:

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

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

a decoder detecting the scanning sequence of transform coefficients used in transform coding, and decoding the transform coefficients to produce information representative of said first motion video signal including said first and second video images;

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

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

an interpolator, operatively connected to said predictive signal generator, and interpolating at least some of the plurality of predictive signals and generating an interpolated predictive signal which is different from any of the other plural 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;

a block deformer decomposing the blocked signal representative of the second video image into the predictive error signal to remove the blocking therefrom

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

a combiner, operatively connected to said block deformer, and combining the predictive error signal obtained from said block deformer with a predictive signal produced by said interpolator or said predictive signal generator;

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

means for outputting a reproduced video signal.

26. The video signal conversion system of claim 25 wherein the scanning sequence used in transform coding the transform coefficients is determined based on coding efficiency.