Patent ID: 11915401
Assignee: SHENZHEN INSTITUTES OF ADVANCED TECHNOLOGY
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 5:
6. The method according to claim 5, wherein the specified joint loss function comprises a mean absolute error function LMAE, a perceptive loss function LPCP, and adversarial loss functions LGANG and LGAND, expressed as:, L
    comb
   
   =
   
    
     L
     MAE
    
    +
    
     
      λ
      1
     
     ·
     
      L
      PCP
     
    
    +
    
     
      λ
      2
     
     ·
     
      L
      GAN
      G
     
    
   
  
  ,
 

 
  
   
    L
    MAE
   
   =
   
    E
    [
    
     y
     -
     
      G
      ⁡
      (
      x
      )
     
    
    ]
   
  
  ,
 

 
  
   
    L
    PCP
   
   =
   
    
     
      ∑
       
     
     i
     n
    
    ⁢
    
     E
     [
     
      
       
        ϕ
        i
       
       (
       y
       )
      
      -
      
       
        ϕ
        i
       
       (
       
        G
        ⁡
        (
        x
        )
       
       )
      
     
     ]
    
   
  
  ,
 

 
  
   
    L
    GAN
    G
   
   =
   
    E
    [
    
     log
     ⁡
     (
     
      D
      ⁡
      (
      
       G
       ⁡
       (
       x
       )
      
      )
     
     )
    
    ]
   
  
  ,
 

 
  
   
    L
    GAN
    D
   
   =
   
    E
    [
    
     
      log
      ⁡
      (
      
       D
       ⁡
       (
       y
       )
      
      )
     
     +
     
      log
      ⁡
      (
      
       1
       -
       
        D
        ⁡
        (
        
         G
         ⁡
         (
         x
         )
        
        )
       
      
      )
     
    
    ]
   
  
  ,
 

wherein x represents the PET image inputted by a model, y represents a corresponding target reference image, G represents the generator, D represents the discriminator, E represents a mathematical expectation, ϕi represents an ith encoded convolutional layer of a VGG19 model, n represents a number of selected convolutional layers, λ1 and λ2 represent weight coefficients of corresponding functions, and LGAN2 represents a loss function of the discriminator.