height = getHeight();
width = getWidth();

v = newArray(width*height);

for(y = 1; y < height-1; y++){
    for(x = 1; x < width-1; x++){
        if(getPixel(x,y) != 255 && getPixel(x-1,y+1) != 255 && getPixel(x+1,y-1) != 255 && getPixel(x-1,y-1) != 255 && getPixel(x+1,y+1) != 255){
            v[x+y*width] = 0;
        }else{
            v[x+y*width] = 255;
        }
    }
}

for(y = 1; y < height-1; y++){
    for(x = 1; x < width-1; x++){
        setPixel(x, y, v[x+y*width]);
    }
}