Image information decoding apparatus and image information decoding method for motion prediction and/or compensation of images

Abstract

The present invention is directed to an image information encoding apparatus, used in receiving compressed image information through network media when processing of such compressed image information is performed on storage media. A picture sorting buffer delivers information of picture type of frame Picture_type to a picture type discrimination unit. The picture type discrimination unit transmits command to a motion prediction/compensation unit on the basis of that information. The motion prediction/compensation unit generates predictive picture by using filter coefficients having the number of taps lesser than that of P picture with respect to B picture for which operation quantity and the number of memory accesses are required to more degree as compared to P picture on the basis of that command.

1 . A decoding apparatus for decoding comprising:
 a motion compensator, including a processor, configured to perform motion compensation by applying an 8-tap filter to a P picture and to perform motion prediction by applying a 6-tap filter to a B picture.   
     
     
         2 . The decoding apparatus as set forth in  claim 1 , wherein the motion compensator has pixel accuracies of motion compensation which are equal to each other with respect to the P picture and the B picture. 
     
     
         3 . The decoding apparatus as set forth in  claim 1 , wherein the motion compensator is configured to select motion compensation by different pixel accuracies with respect to the P picture and the B picture. 
     
     
         4 . The decoding apparatus as set forth in  claim 3 , wherein the motion compensator is configured to perform motion compensation of 1/4 pixel accuracy with respect to the P picture, and to perform motion compensation of 1/2 pixel accuracy with respect to the B picture. 
     
     
         5 . The decoding apparatus as set forth in  claim 1 , wherein the motion compensator is configured to perform motion compensation of 1/8 pixel accuracy, and to perform interpolation of 1/8 pixel accuracy by using the 8-tap filter expressed below
   {−1, 6, −21, 71, 485, −37, 12, −3}/512.
   
     
     
         6 . The decoding apparatus as set forth in  claim 1 , wherein the motion compensator is configured to perform motion compensation of 1/4 pixel accuracy, and to perform interpolation of 1/4 pixel accuracy by using the 8-tap filter expressed below
   {−1, 6, −21, 71, 229, −37, 12, −3}/256.
   
     
     
         7 . The decoding apparatus as set forth in  claim 1 , wherein the motion compensator is configured to perform motion compensation of 1/4 pixel accuracy, and to perform interpolation of 1/2 pixel accuracy by using the 6-tap filter expressed below
   {1, −5, 20, 20, −5, 1}/32.
   
     
     
         8 . A decoding method, the method comprising:
 performing motion compensation by applying an 8-tap filter to a P picture and to perform motion prediction by applying a 6-tap filter to a B picture.   
     
     
         9 . The decoding method as set forth in  claim 8 , wherein pixel accuracies of motion compensation are equal to each other with respect to the P picture and the B picture. 
     
     
         10 . The decoding method as set forth in  claim 8 , further comprising selecting motion compensation by different pixel accuracies with respect to the P picture and the B picture. 
     
     
         11 . The decoding method as set forth in  claim 10 , further comprising performing motion compensation of 1/4 pixel accuracy with respect to the P picture, and performing motion compensation of 1/2 pixel accuracy with respect to the B picture. 
     
     
         12 . The decoding method as set forth in  claim 8 , further comprising performing motion compensation of 1/8 pixel accuracy, and performing interpolation of 1/8 pixel accuracy by using the 8-tap filter expressed below
   {−1, 6, −21, 71, 485, −37, 12, −3}/512.
   
     
     
         13 . The decoding method as set forth in  claim 8 , further comprising performing motion compensation of 1/4 pixel accuracy, and performing interpolation of 1/4 pixel accuracy by using the 8-tap filter expressed below
   {−1, 6, −21, 71, 229, −37, 12, −3}/256.
   
     
     
         14 . The decoding method as set forth in  claim 8 , further comprising performing motion compensation of 1/4 pixel accuracy, and performing interpolation of 1/2 pixel accuracy by using the 6-tap filter expressed below
   {1, −5, 20, 20, −5, 1}/32.
   
     
     
         15 . A non-transitory computer readable medium having stored thereon computer-executable instructions which when executed cause a computer to:
 perform motion compensation by applying an 8-tap filter to a P picture and to perform motion prediction by applying a 6-tap filter to a B picture.   
     
     
         16 . The non-transitory computer readable medium as set forth in  claim 15 , wherein pixel accuracies of motion compensation are equal to each other with respect to the P picture and the B picture. 
     
     
         17 . The non-transitory computer readable medium as set forth in  claim 15 , further comprising selecting motion compensation by different pixel accuracies with respect to the P picture and the B picture. 
     
     
         18 . The non-transitory computer readable medium as set forth in  claim 15 , further comprising performing motion compensation of 1/8 pixel accuracy, and performing interpolation of 1/8 pixel accuracy by using the 8-tap filter expressed below
   {−1, 6, −21, 71, 485, −37, 12, −3}/512.
   
     
     
         19 . The non-transitory computer readable medium as set forth in  claim 15 , further comprising performing motion compensation of 1/4 pixel accuracy, and performing interpolation of 1/4 pixel accuracy by using the 8-tap filter expressed below
   {−1, 6, −21, 71, 229, −37, 12, −3}/256.
   
     
     
         20 . The non-transitory computer readable medium as set forth in  claim 15 , further comprising performing motion compensation of 1/4 pixel accuracy, and performing interpolation of 1/2 pixel accuracy by using the 6-tap filter expressed below
   {1, −5, 20, 20, −5, 1}132.