Method and Apparatus for Syntax Redundancy Removal in Palette Coding

Abstract

A method and apparatus for palette coding of a block of video data using a candidate prediction mode list with syntax redundancy removed are disclosed. In one embodiment, whether a redundant prediction mode exists in the candidate prediction mode list for the current samples of the current block is determined based on the candidate prediction mode list and the previous prediction mode associated with the previous samples. If the redundant prediction mode exists in the candidate prediction mode list, the redundant prediction mode is removed from the candidate prediction mode list to generate a reduced candidate prediction mode list. In another embodiment, whether a redundant predictor exists in a candidate predictor list for a current sample of the current block is determined based on a condition related to one or more predictors for the current sample of the current block.

1 . A method of coding a block of video data using palette coding in a video coding system, the method comprising:
 receiving input data associated with a current block;   determining at least one first palette syntax; and   if at least one sample coded as an escape pixel exists in the current block, applying escape-sample encoding or decoding to the at least one sample coded as an escape pixel to generate at least one second palette syntax of the at least one sample coded as an escape pixel after the at least one first palette syntax.   
     
     
         2 . The method of  claim 1 , wherein the at least one first palette syntax comprises at least one of the syntaxes of palette table coding, palette escape value present flag, palette transpose flag, palette run mode, palette run, and palette index. 
     
     
         3 . The method of  claim 1 , wherein the at least one second palette syntax comprises an escape value of the at least one sample coded as an escape pixel. 
     
     
         4 . The method of  claim 1 , wherein the at least one second palette syntax comprises an escape value of at least one color component of the at least one sample coded as an escape pixel. 
     
     
         5 . The method of  claim 1 , wherein the at least one second palette syntax is signaled at the end of the syntax coding of the current CU, or after index signaling of the current CU or after index map coding of the current CU or after prediction pattern signaling of the current CU. 
     
     
         6 . The method of  claim 1 , wherein the at least one first palette syntax associates with a palette index map. 
     
     
         7 . The method of  claim 1 , wherein when the number of the at least one first palette syntax is more than one, the at least one second palette syntax is not generated before any of the first palette syntaxes. 
     
     
         8 . An apparatus of coding a block of video data using palette coding in a video coding system, the apparatus comprising one or more electronic circuits configured to:
 receiving input data associated with a current block;   determining at least one first palette syntax; and   if at least one sample coded as an escape pixel exists in the current block, applying escape-sample encoding or decoding to the at least one sample coded as an escape pixel to generate at least one second palette syntax of the at least one sample coded as an escape pixel after the at least one first palette syntax.   
     
     
         9 . The apparatus of  claim 8 , wherein the at least one first palette syntax comprises at least one of the syntaxes of palette table coding, palette escape value present flag, palette transpose flag, palette run mode, palette run, and palette index. 
     
     
         10 . The apparatus of  claim 8 , wherein the at least one second palette syntax comprises an escape value of the at least one sample coded as an escape pixel. 
     
     
         11 . The apparatus of  claim 8 , wherein the at least one second palette syntax comprises an escape value of at least one color component of the at least one sample coded as an escape pixel. 
     
     
         12 . The apparatus of  claim 8 , wherein the at least one second palette syntax is signaled at the end of the syntax coding of the current CU, or after index signaling of the current CU or after index map coding of the current CU or after prediction pattern signaling of the current CU. 
     
     
         13 . The apparatus of  claim 8 , wherein the at least one first palette syntax associates with a palette index map. 
     
     
         14 . The apparatus of  claim 8 , wherein when the number of the at least one first palette syntax is more than one, the at least one second palette syntax is not generated before any of the first palette syntaxes.