Smooth Filter

InitGraph();
rows=31;cols=47;
ScaleWindow(0, 0,cols+1, rows+1);
Colour(Black);
BoxFill(0,0,cols+1,rows+1);

pic1=new Array(cols);pic2=new Array(cols);
for(var i = 0;i<=cols;i++){
   pic1[i]=new Array(rows);pic2[i]=new Array(rows);
}

function showpic2() {         //and copy to pic1
 for(var i = 0;i<=cols;i++){
   for(var j = 0;j<=rows;j++) {
      m=5*pic2[i][j]
      ColourRGB(m,m,m);
      BoxFill(i, j, 1.1, 1.1);
      Colour(Red);
      pic1[i][j]=pic2[i][j];
   }
 }
}

function blurrh() {
 b = 6.;            //sets the 'blur' constant
 for(var j = 0;j<=rows;j++) {
   a = pic1[0][j];
   for(var i = 0;i<=cols;i++){
      a = a + (pic1[i][j] - a) / b;
      pic1 [i][j] = a;
      c=6*a;
      ColourRGB(c,c,c);
      BoxFill(i, j, 1, 1);
   }
   for(var i = cols-1;i>=0;i+=-1){
      a = a + (pic1 [i][j] - a) / b;
      pic1 [i][j] = a;
      c=6*a;
      ColourRGB(c,c,c);
      BoxFill(i, j, 1, 1);
   }
 }
}

function blurrv() {
 b = 6;               //sets the 'blur' constant
 for(var i = 0;i<=cols;i++){
   var a = pic1 [i][0];
   for(var j = 0;j<=rows;j++) {
      a = a + (pic1[i][j] - a) / b;
      pic1 [i][j] = a;
      c=6*a;
      ColourRGB(c,c,c);
      BoxFill(i, j, 1, 1);
   }
   for(j = rows-1;j>=0;j+=-1) {
      a = a + (pic1[i][j] - a) / b;
      pic1 [i][j] = a;
      c=6*a;
      ColourRGB(c,c,c);
      BoxFill(i, j, 1, 1);
   }
 }
}

//Set up picture with a ragged diamond
Colour(Dull);
m=(rows+cols)/2;
for (i = 0;i<= cols;i++){ 
   for (j = 0; j<=rows;j++) {
      k = m - Math.abs(i - cols/2) - Math.abs(j - rows/2);
      k = k + 12. * Math.random();
      pic1 [i][j] = k; 
      c = 5 * k;
      ColourRGB(c, c, c);
      BoxFill(i, j, 1, 1);
   }
}

blurrh();
    blurrv();