Patent ID: 11915392
Assignee: SHANGHAI LINKCHIP SEMICONDUCTOR TECHNOLOGY CO., LTD.
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 3:
4. The image enhancement method according to claim 3, wherein the step of calculating a weight according to the low frequency sub-band of the brightness component of the corresponding layer comprises:, ⁢
        
          
            
              W
              N
            
            ⁡
            
              (
              
                
                  x
                  +
                  i
                
                ,
                
                  y
                  +
                  j
                
              
              )
            
          
          =
          
            
              
                
                  WD
                  N
                
                ⁡
                
                  (
                  
                    
                      x
                      +
                      i
                    
                    ,
                    
                      y
                      +
                      j
                    
                  
                  )
                
              
              *
            
            ⁢
            
              
                WR
                N
              
              ⁡
              
                (
                
                  
                    x
                    +
                    i
                  
                  ,
                  
                    y
                    +
                    j
                  
                
                )
              
            
          
        
      
    
    
      
        (
        3
        )
      
    
  
  
    
      
        
          
        
        ⁢
        
          
            
              WD
              N
            
            ⁡
            
              (
              
                
                  x
                  +
                  i
                
                ,
                
                  y
                  +
                  j
                
              
              )
            
          
          =
          
            exp
            (
            
              -
              
                
                  
                    i
                    2
                  
                  +
                  
                    j
                    2
                  
                
                
                  2
                  ⁢
                  
                    
                      δ_
                      ⁢
                      G
                    
                    N
                    2
                  
                
              
            
            )
          
        
      
    
    
      
        (
        4
        )
      
    
  
  
    
      
        
          
            WR
            N
          
          ⁡
          
            (
            
              
                x
                +
                i
              
              ,
              
                y
                +
                j
              
            
            )
          
        
        =
        
          {
          
            
              
                
                  
                    EI
                    N
                  
                  ⁡
                  
                    (
                    
                      
                        x
                        +
                        i
                      
                      ,
                      
                        y
                        +
                        j
                      
                    
                    )
                  
                
              
              
                
                  
                    
                      EI
                      N
                    
                    ⁡
                    
                      (
                      
                        
                          x
                          +
                          i
                        
                        ,
                        
                          y
                          +
                          j
                        
                      
                      )
                    
                  
                  >
                  0
                
              
            
            
              
                0
              
              
                
                  
                    
                      EI
                      N
                    
                    ⁡
                    
                      (
                      
                        
                          x
                          +
                          i
                        
                        ,
                        
                          y
                          +
                          j
                        
                      
                      )
                    
                  
                  ≤
                  0
                
              
            
          
        
      
    
    
      
        (
        5
        )
      
    
  
  
    
      
        
          
            EI
            N
          
          ⁡
          
            (
            
              
                x
                +
                i
              
              ,
              
                y
                +
                j
              
            
            )
          
        
        =
        
          16
          -
          
            
              
                (
                
                  
                    
                      Y_LL
                      N
                    
                    ⁢
                    
                      (
                      
                        
                          x
                          +
                          i
                        
                        ,
                        
                          y
                          +
                          j
                        
                      
                      )
                    
                  
                  -
                  
                    
                      Y_LL
                      N
                    
                    ⁢
                    
                      (
                      
                        x
                        ,
                        y
                      
                      )
                    
                  
                
                )
              
              2
            
            
              2
              ⁢
              
                
                  δ_
                  ⁢
                  Y
                
                N
                2
              
            
          
          -
          
            
              
                (
                
                  
                    
                      U_LL
                      N
                    
                    ⁢
                    
                      (
                      
                        
                          x
                          +
                          i
                        
                        ,
                        
                          y
                          +
                          j
                        
                      
                      )
                    
                  
                  -
                  
                    
                      
                        (
                        
                          U
                          ⁢
                          _LL
                        
                        )
                      
                      N
                    
                    ⁢
                    
                      (
                      
                        x
                        ,
                        y
                      
                      )
                    
                  
                
                )
              
              2
            
            
              2
              ⁢
              
                
                  δ_
                  ⁢
                  U
                
                N
                2
              
            
          
          -
          
            
              
                (
                
                  
                    
                      V_LL
                      N
                    
                    ⁢
                    
                      (
                      
                        
                          x
                          +
                          i
                        
                        ,
                        
                          y
                          +
                          j
                        
                      
                      )
                    
                  
                  -
                  
                    
                      V_LL
                      N
                    
                    ⁢
                    
                      (
                      
                        x
                        ,
                        y
                      
                      )
                    
                  
                
                )
              
              2
            
            
              2
              ⁢
              
                
                  δ_
                  ⁢
                  V
                
                N
                2
              
            
          
        
      
    
    
      
        (
        6
        )
      
    
  

wherein δ_GN is a Gaussian kernel variance in an Nth-layer bilateral filtering, δ_YN,δ_UN and δ_VN are respectively Y, U, V component variances of the Nth layer, WDN(x+i, y+j) is a domain weight in the bilateral filtering, WRN(x+i, y+j) is a range weight in the bilateral filtering, EIN(x+i, y+j) is a comprehensive edge indicator, Y_LLN(x, y) is a low frequency sub-band of a Y component pixel (x,y) of the Nth layer, Y_LLN(x+i, y+j) is a pixel set of the Y component pixel Y_LLN(x, y) taking the Gaussian kernel size WINN as the radius.