LINEAR I'UKDU'TION IN TELEVISION 



771 



"Planar" prediction, shown in Fi^. 8, is effectively tandem operation 

 of "previous value" and "previous line" prediction. Planar prediction 

 may also be thought of as the \alue represented by a plane above the 

 present value of the signal when passed through three adjacent signal 



PREVIOUS LINE PREDICTION 



Fig. 7 — Example of "previous line" prediction. Here the error signal is the 

 difference between the actual value of the signal and the value of the signal on 

 the line directly above. 



PLANAR PREDICTION 



SIGNAL OF 

 PREVIOUS LINE 



Sp= 5, 

 e = S, 



+ 5, 



' 0,0 ■-'1,0 -^0,1 ■'" -^1,1 



Fig. 8 — An example of • planar" prediction. Here the prediction is represented 

 by a plane that has been passed through three adjacent signal values. 



