Video encoding and decoding apparatus

Abstract

An encoding apparatus includes an encoder for encoding an alpha-map signal for discriminating a background from an object of an input picture in motion compensation prediction (MV)+transform encoding which uses MV in a domain of each of N×N transform coefficients (n), a transform circuit for transforming Pf into n in accordance with the alpha-map signal, an inverse transform circuit for reconstructing Pf by inversely transforming n in accordance with the alpha-map signal, a selector for obtaining a motion compensation prediction value (p) in the mth layer (m=2 to M) by switching p in the mth layer and p in the (m−1)th layer for each n, the selector selecting p in the mth layer for n by which a quantized output (Q) in the (m−1)th layer is 0 and selecting p in the (m−1)th layer for n by which Q=1 or more, an adder for calculating a difference df between a prediction error signal in the mth layer and a dequantized output in the (m−1)th layer, and an encoder for encoding and outputting the quantized signal of df. This encoding apparatus realizes SNR scalability in M layers.

1. A video decoding apparatus comprising:
 decoder means for decoding an encoded alpha-map signal for discriminating a background of an input signal and at least one object thereof;  
 motion compensation prediction decoder means for decoding an arbitrary shape picture of the object in accordance with the alpha-map signal to obtain a decoded arbitrary shape picture signal; and  
 a plurality of memory means for storing a background signal representing the background and the decoded arbitrary shape picture signal, respectively, the decoded arbitrary shape picture signal being read out from the plurality of memory means to be used for a motion compensation prediction of the decoded arbitrary shape picture.  
 
     
     
       2. A video decoding apparatus according to  claim 1 , further comprising write switch means for selectively switching the plurality of memory means in accordance with the alpha-map signal to selectively store the background signal and the decoded arbitrary shape picture signal in the memory means. 
     
     
       3. A video decoding apparatus according to  claim 1 , further comprising read switch means for selectively switching the plurality of memory means in accordance with the alpha-map signal to selectively read out the background signal and the decoded arbitrary shape picture signal therefrom. 
     
     
       4. A video decoding apparatus according to  claim 1 , wherein the plurality of memory means include a plurality of first memory means for storing, respectively, decoded arbitrary shape picture signals representing different objects as well as second memory means for storing the background signal. 
     
     
       5. A video decoding apparatus according to  claim 4 , further comprising write switch means for selectively switching the plurality of first memory means and the second memory means in accordance with the alpha-map signal to selectively store the decoded arbitrary shape picture signals corresponding to the objects and the background signal therein. 
     
     
       6. A video decoding apparatus according to  claim 4 , further comprising read switch means for selectively switching the first memory means and the second memory means in accordance with the alpha-map signal to read out the decoded arbitrary shape picture signals and the background signal therefrom. 
     
     
       7. A video decoding apparatus according to  claim 4 , further comprising:
 motion compensation prediction means for calculating a motion compensation prediction value on the basis of readout one of the decoded arbitrary shape picture signals and motion vector information input to the motion compensation prediction means; and  
 transform means for orthogonally transforming the motion compensation prediction value on the basis of the alpha-map signal to obtain an orthogonal transform coefficient of the motion compensation prediction value of a picture of the arbitrary shape indicated by the alpha-map signal.  
 
     
     
       8. A video decoding apparatus according to  claim 7 , wherein the motion compensation prediction means calculates the motion compensation prediction value for each of the decoded arbitrary shape picture signals stored in the memories in accordance with the alpha-map signal. 
     
     
       9. A video decoding apparatus comprising:
 decoder means for decoding a coded alpha-map signal for discriminating a background of an input signal and a plurality of objects thereof;  
 motion compensation prediction decoder means for decoding arbitrary shape pictures of the objects in accordance with the alpha-map signal to obtain a plurality of decoded arbitrary shape picture signals; and  
 a plurality of memory means for storing the decoded arbitrary shape picture signals, respectively, the decoded arbitrary shape picture signals being independently read out from the memory means to be used for a motion compensation prediction of each of the decoded arbitrary shape picture signals.  
 
     
     
       10. A video decoding apparatus comprising:
 a decoder configured to decode a coded alpha-map signal for discriminating a background of an input signal and at least one object thereof;  
 a motion compensation prediction decoder configured to decode an arbitrary shape picture of the object in accordance with the alpha-map signal to obtain a decoded arbitrary shape picture signal; and  
 a plurality of memories configured to store a background signal of the object and the decoded arbitrary shape picture signal, respectively, the decoded arbitrary shape picture signal being read out from the memories to be used for a motion compensation prediction of the decoded arbitrary shape picture signal.  
 
     
     
       11. A video decoding apparatus according to  claim 10 , further comprising a write switch section configured to selectively switch the memories in accordance with the alpha-map signal to selectively store the background signal and the decoded arbitrary shape picture in the memories. 
     
     
       12. A video decoding apparatus according to  claim 10 , further comprising a read switch section configured to selectively switch the memories in accordance with the alpha-map signal to selectively read out the background signal and the decoded arbitrary shape picture signal therefrom. 
     
     
       13. A video decoding apparatus according to  claim 10 , wherein the memories include a plurality of first memories configured to store, respectively, decoded arbitrary shape picture signals representing different objects as well as a second memory configured to store the background signal. 
     
     
       14. A video decoding apparatus according to  claim 13 , further comprising a write switch section configured to selectively switch the first memories and the second memory in accordance with the alpha-map signal to selectively store the decoded arbitrary shape picture signals corresponding to the objects and the background signal therein. 
     
     
       15. A video decoding apparatus according to  claim 13 , further comprising a read switch section configured to selectively switch the first memories and the second memory in accordance with the alpha-map signal to read out the decoded arbitrary shape picture signals corresponding to the objects and the background picture therefrom. 
     
     
       16. A video decoding apparatus according to  claim 13 , further comprising:
 a motion compensation prediction section configured to calculate a motion compensation prediction value on the basis of readout one of the decoded arbitrary shape picture signals and motion vector information input to the motion compensation prediction section; and  
 a transform section configured to orthogonally transform the motion compensation prediction value on the basis of the alpha-map signal to obtain an orthogonal transform coefficient of the motion compensation prediction value of a picture of the arbitrary shape indicated by the alpha-map signal.  
 
     
     
       17. A video decoding apparatus according to  claim 16 , wherein the motion compensation prediction section calculates the motion compensation prediction value for each of the decoded arbitrary shape picture signals stored in the memories in accordance with the alpha-map signal. 
     
     
       18. A video decoding apparatus comprising:
 a decoder configured to decode a coded alpha-map signal for discriminating a background of an input signal and at least one object thereof;  
 a motion compensation prediction decoder configured to decode arbitrary shape pictures of objects in accordance with the alpha-map signal to obtain decoded arbitrary shape picture signals; and  
 a plurality of memories configured to store the decoded arbitrary shape picture signals, respectively, the decoded arbitrary shape picture signals being independently read out from the memories to be used for a motion compensation prediction of each of the decoded arbitrary shape picture signals.  
 
     
     
       19. A video decoding method comprising:
 decoding a coded alpha-map signal for discriminating a background of an input signal and at least one object thereof;  
 decoding an arbitrary shape picture of the object in accordance with the alpha-map signal to obtain a decoded arbitrary shape picture signal; and  
 storing a background signal representing the background and the decoded arbitrary shape picture signal in a plurality of memories, respectively, the decoded arbitrary shape picture signal being read out from one of the memories to be used for a motion compensation prediction of the decoded arbitrary shape picture signal.  
 
     
     
       20. A video decoding method according to  claim 19 , further comprising selectively switching the memories in accordance with the alpha-map signal to selectively store the background signal and the decoded arbitrary shape picture signal in the memories. 
     
     
       21. A video decoding method according to  claim 19 , further comprising selectively switching the memories in accordance with the alpha-map signal to selectively read out the background signal and the decoded arbitrary shape picture signal therefrom. 
     
     
       22. A video decoding method according to  claim 19 , wherein the memories include a plurality of first memories for storing, respectively, decoded arbitrary shape picture signals representing different objects as well as a second memory for storing the background signal. 
     
     
       23. A video decoding method according to  claim 22 , further comprising selectively switching the first memories and the second memory in accordance with the alpha-map signal to selectively store the decoded arbitrary shape picture signals corresponding to the objects and the background signal therein. 
     
     
       24. A video decoding method according to  claim 22 , further comprising selectively switching the first memories and the second memory in accordance with the alpha-map signal to read out the decoded arbitrary shape picture signals and the background signal therefrom. 
     
     
       25. A video decoding method according to  claim 22 , further comprising:
 calculating a motion compensation prediction value on the basis of readout of one of the decoded arbitrary shape picture signals and motion vector information being input to a motion compensation prediction section; and  
 orthogonally transforming the motion compensation prediction value on the basis of the alpha-map signal to obtain an orthogonal transform coefficient of the motion compensation prediction value of a picture of the arbitrary shape indicated by the alpha-map signal.  
 
     
     
       26. A video decoding method according to  claim 25 , wherein the step of calculating a motion compensation prediction value includes the step of calculating the motion compensation prediction value for each of the decoded arbitrary shape picture signals stored in the memories in accordance with the alpha-map signal. 
     
     
       27. A video decoding method comprising:
 decoding a coded alpha-map signal for discriminating a background of an input signal and at least one object thereof;  
 decoding arbitrary shape pictures of objects in accordance with the alpha-map signal to obtain decoded arbitrary shape picture signals; and  
 storing the decoded arbitrary shape picture signals in a plurality of memories, respectively, the decoded arbitrary shape picture signals being independently read out from the memories to be used for a motion compensation prediction of each of the reconstructed picture signals.  
 
     
     
       28. A computer system for video encoding, comprising:
   an encoder configured to encode an alpha - map signal for discriminating a background of an input signal and at least an object thereof;        a motion compensation prediction encoder configured to encode an arbitrary shape picture of the object in accordance with the alpha map signal to obtain a coded arbitrary shape picture;        a local decoder configured to decode the coded arbitrary shape picture to reconstruct the arbitrary shape picture of the object and output a reconstructed picture signal representing the object;        first memory means for storing a background signal representing the background of the input signal; and        second memory means for storing the reconstructed picture signal representing the object, the reconstructed picture signal being read out from the second memory means to be used for motion compensation prediction encoding of the arbitrary shape picture of the object.     
     
     
       29. A computer system according to  claim 28 , further comprising:
   a write controller configured to selectively switch the first memory means and the second memory means in accordance with the alpha - map signal to store selectively the reconstructed picture signal and the background signal therein.     
     
     
       30. A computer system according to  claim 28 , further comprising:
   a read controller configured to selectively switch the first memory means and the second memory means in accordance with the alpha - map signal to read out selectively the reconstructed picture signal and the background signal therefrom.     
     
     
       31. A computer system for video encoding, comprising:
   an encoder configured to encode an alpha - map signal for discriminating a background of an input signal and a plurality of objects thereof,        a motion compensation prediction encoder configured to encode an arbitrary shape pictures of the objects in accordance with the alpha - map signal to obtain a plurality of coded arbitrary shape pictures;        a local decoder configured to decode the coded arbitrary shape pictures to reconstruct the arbitrary shape pictures of the objects and to output a plurality of reconstructed picture signals representing the objects; and        a plurality of second memory means for storing the reconstructed picture signals, respectively, the reconstructed picture signals being read out from the second memory means to be used for motion compensation prediction encoding of each of the arbitrary shape pictures of the objects.     
     
     
       32. A computer system according to  claim 31 , further comprising:
   a write controller configured to selectively switch the plurality of second memory means in accordance with the alpha - map signal to selectively store the reconstructed picture signals corresponding to the objects therein.     
     
     
       33. A computer system according to  claim 31 , further comprising:
   a read switch controller configured to selectively switch the second memory means in accordance with the alpha - map signal to read out the reconstructed picture signals corresponding to the objects therefrom.     
     
     
       34. A computer system according to  claim 31 , further comprising:
   a motion compensation predictor configured to calculate motion signals and motion vector information input; and        a transformer configured to orthogonally transform a motion compensation prediction value on the basis of the alpha - map signal to obtain an orthogonal transform coefficient of the motion compensation prediction value of a picture of the arbitrary shape indicated by the alpha - map signals.     
     
     
       35. A computer system according to  claim 34 , wherein the motion compensation predictor includes a calculator configured to calculate the motion compensation prediction value for each of the reconstructed picture signals stored in the second memory means in accordance with the alpha- map signal.   
     
     
       36. A computer system for video encoding, comprising:
   an encoder configured to encode an alpha - map signal for discriminating a background of an input signal and at least one object thereof;        a motion compensation prediction encoder configured to encode an arbitrary shape picture of the object in accordance with the alpha - map signal to obtain a coded arbitrary shape picture;        a local decoder configured to decode the coded arbitrary shape picture to reconstruct the arbitrary shape picture of the object and output a reconstructed picture signal representing the object;        a first memory configured to store a background signal representing the background of the input signal; and        a second memory configured to store the reconstructed picture signal representing the object, the reconstructed picture signal being read out from the second memory to be used for motion compensation prediction encoding of the arbitrary shape picture of the object.     
     
     
       37. A computer system according to  claim 36 , further comprising:
   a write switch section configured to selectively switch the first memory and the second memory in accordance with the alpha - map signal to store selectively the reconstructed picture signal and the background signal therein.     
     
     
       38. A computer system according to  claim 36 , further comprising:
   a read switch section configured to selectively switch the first memory and the second memory in accordance with the alpha - map signal to read out selectively the reconstructed picture signal and the background signal therefrom.     
     
     
       39. A computer system for video encoding, comprising:
   an encoder configured to encode an alpha - map signal for discriminating a background of an input signal and a plurality of objects thereto;        a motion compensation prediction encoder configured to encode arbitrary shape pictures of the objects in accordance with the alpha - map signal to obtain a plurality of coded arbitrary shape pictures;        a local decoder configured to decode the coded arbitrary shape pictures to reconstruct the arbitrary shape pictures of the objects and to output a plurality of reconstructed picture signals representing the objects;        a first memory configured to store a background signal representing the background of the input signal; and        a plurality of second memories configured to store the reconstructed picture signals representing the objects, respectively, the reconstructed picture signals being read out from the second memories to be used for motion compensation prediction encoding of each of the arbitrary shape pictures of the objects.     
     
     
       40. A computer system according to  claim 39 , further comprising:
   a write switch section configured to selectively switch the second memories in accordance with the alpha - map signal to selectively store the reconstructed picture signals corresponding to the objects therein.     
     
     
       41. A computer system according to  claim 39 , further comprising:
   a read switch section configured to selectively switch the second memories in accordance with the alpha - map signal to read out the reconstructed picture signals corresponding to the objects therefrom.     
     
     
       42. A computer system according to  claim 39 , further comprising:
   a motion compensation prediction section configured to calculate a motion compensation prediction value on the basis of the readout of one of the reconstructed picture signals and motion vector information input to the motion compensation prediction section; and a transform section configured to orthogonally transform the motion compensation prediction value on the basis of the alpha - map signal to obtain an orthogonal transform coefficient of the motion compensation prediction value of a picture of the arbitrary shape indicated by the alpha - map signal.     
     
     
       43. A computer system according to  claim 42 , wherein the motion compensation prediction section includes a section configured to calculate the motion compensation prediction value for each of the reconstructed picture signals stored in the second memories in accordance with the alpha- map signal.   
     
     
       44. A method of encoding video, comprising the steps of:
   encoding an alpha - map signal for discriminating a background of an input signal and at least one object thereof;        encoding an arbitrary shape picture of the object in accordance with the alpha - map signal to obtain a coded arbitrary shape picture;        decoding the coded arbitrary shape picture to reconstruct the arbitrary shape picture of the object and output a reconstructed picture signal representing the object;        storing a background signal representing the background of the input signal in a first memory;        storing the reconstructed picture signal in a second memory representing the object; selectively switching the first memory and the second memory in accordance with the alpha - map signal to store selectively the reconstructed picture signal and the background signal therein; and        reading the reconstructed picture signal out from the second memory to be used for motion compensation prediction encoding of the arbitrary shape picture of the object.     
     
     
       45. A method of encoding video, comprising the steps of:
   encoding an alpha - map signal for discriminating a background of an input signal and at least one object thereof;        encoding an arbitrary shape picture of the object in accordance with the alpha - map signal to obtain a coded arbitrary shape picture;        decoding the coded arbitrary shape picture to reconstruct the arbitrary shape picture of the object and output a reconstructed picture signal representing the object;        storing in a background signal representing the background of the input signal in a first memory;        storing the reconstructed picture signal representing the object in a second memory;        selectively switching the first memory and the second memory in accordance with the alpha - map signal to read out selectively the reconstructed picture signal and the background signal therefrom; and        reading the reconstructed picture signal out from the second memory to be used for motion compensation prediction encoding of the arbitrary shape picture of the object.     
     
     
       46. A method of encoding video, comprising the steps of:
   encoding an alpha - map signal for discriminating a background of an input signal and a plurality of objects thereof;        encoding arbitrary shape pictures of the objects in accordance with the alpha - map signal to obtain a plurality of coded arbitrary shape pictures;        decoding the coded arbitrary shape pictures to reconstruct the arbitrary shape pictures of the objects and to output a plurality of reconstructed picture signals representing the objects;        storing a background signal in a first memory;        storing the reconstructed picture signals representing the objects in at least one of second memories;        selectively switching the second memories in accordance with the alpha - map signal to selectively store the reconstructed picture signals corresponding to the objects therein; and        reading the reconstructed picture signals out from the at least one of second memories to be used for motion compensation prediction encoding of each of the arbitrary shape pictures of the objects.     
     
     
       47. A method of encoding video, comprising the steps of:
   encoding an alpha - map signal for discriminating a background of an input signal and a plurality of objects thereof;        encoding arbitrary shape pictures of the objects in accordance with the alpha - map signal to obtain a plurality of coded arbitrary shape pictures;        decoding the coded arbitrary shape pictures to reconstruct the arbitrary shape pictures of the objects and to output a plurality of reconstructed picture signals representing the objects;        storing a background signal in a first memory;        storing the reconstructed picture signals representing the objects in at least one of second memories; and        selectively switching the second memories in accordance with the alpha - map signal to read out the reconstructed picture signals corresponding to the objects therefrom; and        reading the reconstructed picture signals out from the at least one of second memories to be used for motion compensation prediction encoding of each of the arbitrary shape pictures of the objects.     
     
     
       48. A method of encoding video, comprising the steps of:
   encoding an alpha - map signal for discriminating a background of an input signal and a plurality of objects thereof;        encoding arbitrary shape pictures of the objects in accordance with the alpha - map signal to obtain a plurality of coded arbitrary shape pictures;        decoding the coded arbitrary shape pictures to reconstruct the arbitrary shape pictures of the objects and to output a plurality of reconstructed picture signals representing the objects;        storing a background signal in a first memory;        storing the reconstructed picture signals representing the objects in at least one of second memories;        reading the reconstructed picture signals out from the at least one of second memories to be used for motion compensation prediction encoding of each of the arbitrary shape pictures of the objects;        calculating a motion compensation prediction value based on the reading step and motion vector information; and        orthogonally transforming the motion compensation prediction value on the basis of the alpha - map signal to obtain an orthogonal transform coefficient of the motion compensation prediction value of a picture of the arbitrary shape indicated by the alpha - map signal.     
     
     
       49. A method of encoding video according to  claim 48 , wherein the step of encoding arbitrary shape pictures includes calculating the motion compensation prediction value for each of the reconstructed picture signals stored in the second memories in accordance with the alpha- map signal.   
     
     
       50. A video encoding method comprising:
   encoding an alpha - map signal for discriminating a background of an input signal and at least one object thereof;        encoding an arbitrary shape of the object in accordance with the alpha - map signal to obtain a coded arbitrary shape picture;        decoding the coded arbitrary shape picture to reconstruct the arbitrary shape picture of the object and output a reconstructed picture signal representing the object;        storing a background signal representing the background of the input signal in a first memory;        storing the reconstructed picture signal representing the object in a second memory; and        reading the reconstructed picture signal out from the second memory to be used for motion compensation prediction encoding of the arbitrary shape picture of the object,        wherein the motion compensation prediction encoding includes calculating a motion compensation prediction value based on the reading step and motion vector information.     
     
     
       51. A video encoding method comprising:
   encoding an alpha - map signal for discriminating a background of an input signal and a plurality of objects thereof;        encoding arbitrary shape pictures of the objects in accordance with the alpha - map signal to obtain a plurality of coded arbitrary shape pictures;        decoding the coded arbitrary shape pictures to reconstruct the arbitrary shape pictures of the objects and to output a plurality of reconstructed picture signals representing the objects;        storing the background signal in a first memory;        storing the reconstructed picture signals representing the objects in at least one second memory; and        reading the reconstructed picture signals out from the at least one second memory to be used for motion compensation prediction encoding of each of the arbitrary shape pictures of the objects,        wherein the motion compensation prediction encoding includes calculating a motion compensation prediction value based on the reading step and motion vector information.