| for 
d 
es. 
es. 
amera 
1 their 
are 
cing 
rees 
emporal 
hoto- 
rent. 
ystema- 
nd 
densi- 
diffe- 
roubles 
at 
10 
ctures 
oxactly 
similar 
which 
m shows 
ore 
olour. 
emul- 
s of 
RED 
DENSITY 
  
10 
1975 
O 
® 
<q 
0 
1977 
B A o0 
  
1977 
ABCDEF 
background 
colour 
different groups of 
trees having the same 
position and background 
colour shift on temporal images 
Fig.2