Patent ID: 8693551

Claim:
A method of selecting an optimal angular intra prediction mode for a block-based video coding, the method comprising: calculating following functions for a spatial area S including a texture block beginning with coordinates (x, y): E = ( ∑ ( x , y ) ∈ S ⁢ W ⁡ ( x , y ) · D X 2 ⁡ ( x , y ) - ∑ ( x , y ) ∈ S ⁢ W ⁡ ( x , y ) · D Y 2 ⁡ ( x , y ) ) , ⁢ F = ∑ ( x , y ) ∈ S ⁢ W ⁡ ( x , y ) · D X ⁡ ( x , y ) · D Y ⁡ ( x , y ) , ⁢ A = E 2 E 2 + 4 · F 2 ; wherein W(x,y) is a set of non-negative weight coefficients defined at (x,y)εS; D x (x,y) and D y (x,y) are variations of function P(x,y) in the neighborhood of (x, y) point: D x (x,y)=(P(x+1,y)−P(x−1,y))/2; D y (x,y)=(P(x,y+1)−P(x,y−1))/2; and calculating a minimal activity direction for each case j= 1,4 : 1. E≦0 and F<0; 2. E>0 and F<0; 3. E≧0 and F≧0; and 4. E<0 and F≧0.