JS二阶高斯矩阵

 1 function gaussBlur(radius = 2.0, sigma = 1.5) {
 2     let gaussMatrix = [],
 3         gaussSum = 0.0,
 4         a = 1.0 / (2.0 * Math.PI * sigma * sigma),
 5         b = 1.0 / (2.0 * sigma * sigma);
 6 
 7     for (let i = - radius; i <= radius; i++) {
 8         for (let j = - radius; j <= radius; j++) {
 9             var gxy = a * Math.exp(- (i * i + j * j) * b);
10             gaussMatrix.push(gxy);
11             gaussSum += gxy;// 得到高斯矩阵的和，用来归一化
12         }
13     }
14 
15     for (let i = 0; i < gaussMatrix.length; i++) {
16         gaussMatrix[i] = gaussMatrix[i] / gaussSum;
17     }
18     return gaussMatrix;
19 }