Patent ID: 11900541
Assignee: EDDA TECHNOLOGY, INC.
Field: Medical technology (Instruments)
Classification: CPC G  A | IPC A  G

Claim 17:
18. The system of claim 16, wherein the first 3D coordinate of the first 3D feature point and the second 3D coordinate of the second 3D feature point are determined based on:, [
   
    
     
      
       X
       1
      
     
    
    
     
      
       Y
       1
      
     
    
    
     
      
       Z
       1
      
     
    
   
   ]
  
  =
  
   
    
     M
     camera
    
    [
    
     
      
       
        x
        1
       
      
     
     
      
       
        y
        1
       
      
     
     
      
       1
      
     
    
    ]
   
   ·
   
    s
    1
   
  
 

 
  
   [
   
    
     
      
       X
       2
      
     
    
    
     
      
       Y
       2
      
     
    
    
     
      
       Z
       2
      
     
    
   
   ]
  
  =
  
   
    
     M
     camera
    
    [
    
     
      
       
        x
        2
       
      
     
     
      
       
        y
        2
       
      
     
     
      
       1
      
     
    
    ]
   
   ·
   
    s
    1
   
  
 

where (X1, Y1, Z1) and (X2, Y2, Z2) are respectively three values along X, Y, Z axes for the first and the second 3D coordinates, (x1, y1) and (x2, y2) are respectively the image coordinates of the first and the second 2D feature points, and s1 is a scaling factor along the line of sight corresponding to depth Z, which, when the first and the second 3D feature points have substantially the same depth, can be solved from, d
  =
  
   
    
    
     
      M
      camera
     
     (
     
      
       [
       
        
         
          
           x
           1
          
         
        
        
         
          
           y
           1
          
         
        
        
         
          1
         
        
       
       ]
      
      -
      
       [
       
        
         
          
           x
           2
          
         
        
        
         
          
           y
           2
          
         
        
        
         
          1
         
        
       
       ]
      
     
     )
    
    
   
   ⁢
   
    s
    1
   
  
 

where d on the left side represents the second distance and the expression on the right side represents the first distance and Mcamera is a matrix representing camera parameters obtained via camera calibration.