Patent ID: 11887560
Assignee: DOLBY LABORATORIES LICENSING CORPORATION
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 0:
1. A non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform operations, the operations comprising:
receiving image data with luminance values representing absolute luminance values L to be encoded;
encoding the image data into reference encoded image data; and
outputting the reference encoded image data,
wherein the encoding comprises mapping absolute luminance values into digital code values, the luminance values of the received image data being represented by the digital code values in the reference encoded image data;
wherein the mapping is based at least in part on an inverse of a functional model of:, Y
   =
   
    
     (
     
      
       max
       [
       
        
         (
         
          
           V
           
            1
            /
            m
           
          
          -
          
           c
           1
          
         
         )
        
        ,
        0
       
       ]
      
      
       
        c
        2
       
       -
       
        
         c
         3
        
        ⁢
        
         V
         
          1
          /
          m
         
        
       
      
     
     )
    
    
     1
     /
     n
    
   
  
  ,
 

wherein:
Y is a normalized value of a corresponding one of the absolute luminance values L, wherein 0≤Y≤1,
V is a normalized value of a corresponding one of the digital code values D that are output as reference encoded image data, wherein 0≤V≤1, and
n, m, c1, c2, and c3 are predetermined values, with:, n
   =
   
    
     
      
       2
       ⁢
       6
       ⁢
       1
       ⁢
       0
      
      
       4
       ⁢
       0
       ⁢
       9
       ⁢
       6
      
     
     ×
     
      1
      4
     
    
    ≃
    0.1593017578125
   
  
  ;
 

 
  
   m
   =
   
    
     
      
       2
       ⁢
       5
       ⁢
       2
       ⁢
       3
      
      
       4
       ⁢
       0
       ⁢
       9
       ⁢
       6
      
     
     ×
     128
    
    ≃
    78.84375
   
  
  ;
 

 
  
   
    c
    1
   
   =
   
    
     
      c
      3
     
     -
     
      c
      2
     
     +
     1
    
    =
    
     
      
       3
       ⁢
       4
       ⁢
       2
       ⁢
       4
      
      
       4
       ⁢
       0
       ⁢
       9
       ⁢
       6
      
     
     ≃
     0.8359375
    
   
  
  ;
 

 
  
   
    c
    2
   
   =
   
    
     
      
       2
       ⁢
       4
       ⁢
       1
       ⁢
       3
      
      
       4
       ⁢
       0
       ⁢
       9
       ⁢
       6
      
     
     ×
     32
    
    ≃
    18.8515656
   
  
  ;
  and
 

 
  
   c
   3
  
  =
  
   
    
     
      2
      ⁢
      3
      ⁢
      9
      ⁢
      2
     
     
      4
      ⁢
      0
      ⁢
      9
      ⁢
      6
     
    
    ×
    32
   
   ≃
   
    18.6875
    .