Patent ID: 11937771
Assignee: ASENSUS SURGICAL EUROPE SàRL
Field: Audio-visual technology (Electrical engineering)
Classification: CPC A  G  H | IPC A  G  H

Claim 4:
5. The method of claim 1, comprising, for any point Xw in world coordinate system, calculating the coordinate Xc of the same point in the camera coordinate system according to the following equation:

Xc=CcXw,

where Cc, the camera perspective projection matrix, is of the form, C
   c
  
  =
  
   
    
     α
     [
     
      
       
        
         f
         x
        
       
       
        
         kf
         y
        
       
       
        
         x
         c
         0
        
       
      
      
       
        0
       
       
        
         f
         y
        
       
       
        
         y
         c
         0
        
       
      
      
       
        0
       
       
        0
       
       
        1
       
      
     
     ]
    
    [
    
     
      
       
        R
        c
       
      
      
       
        t
        c
       
      
     
    
    ]
   
   .
  
 

where α is a proportion coefficient, fx and fy are the camera focal length scaled to each of the camera image dimensions, k is the shear of the camera coordinate system, c0 and c0 are the origin of Xc in image coordinates, and Rc and tc define the transformation between the world coordinate system and the light source's coordinate system, with Rc being a rotation matrix and tc a translation matrix.