Lines Matching refs:sigma
31 // g(x) = ( 1 / sqrt( 2 * pi ) * sigma) * e ^ ( -x^2 / 2 * sigma^2 )
33 // and sigma varies with radius.
34 // Based on some experimental radius values and sigma's
35 // we approximately fit sigma = f(radius) as
36 // sigma = radius * 0.3 + 0.6
38 // will resemble a box blur since with large sigma
40 float sigma = 0.3f * (float) radius + 0.6f;
46 float coeff1 = 1.0f / (sqrt(2.0f * pi) * sigma);
47 float coeff2 = - 1.0f / (2.0f * sigma * sigma);
