the stereo pair; n is total pixel number within either patch 
(Fig. 1); 8, b indicate the grey values 
  
  
  
  
  
  
  
  
  
a- l7, 
| ard (22 
fe AS 
To make brief, we denote 
(Aims a 
B;=b;-—b 
apa "p 
Loft Right 
Fig. 1 Image patchs 
Thus (1) can be rewritten as 
0,52 32A, B, — max (4) 
i-1 
(b) Correlation coefficient 
O 45 e ( 5) 
= -—-—-—-—_—_ max 
r v/ 0,4055 m 
where Og, and Ogg are the variance of signal a and b, 
0,47 3241 
| ve (6) 
Oga= DB? 
i21 
(c) Sum of squares of differences 
0,7 $3(A, — B min ez? 
i=1 
In principle, the Least Squares Matching (Ackermann 1983, 
Fürstner 1984) without aditional parameters for radiometric 
transformation is equivalent to this criterion. 
(d) Sum of absolutedi fferences 
x 
— 
9,2 $2|A, — B; | z min C8 
{=] 
(e) After derivative processing 
The digitized image signal can be preprocessed with deriva- 
tives, such as 
AA, =A; —Ain (9.1) 
Mti, = AA; — AA; +ı= A; — 2A ; +1 + A;+2 (9.2) 
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