HTML5 JS实现毛玻璃效果（高斯模糊）
Contents
- 1 HTML5 JS实现毛玻璃效果（高斯模糊）
- 1.1 index.html文件
- 1.2 StackBlur.js文件
- 1.3 index.css文件
- 1.4 代码演示及源码下载
HTML5 JS实现毛玻璃效果（高斯模糊）
苹果IOS系统的毛玻璃效果非常绚丽，自己也想在HTML5中实现同样的效果
css3中可以使用blur来实现这种效果：
.blur {
-webkit-filter: blur(10px);
-moz-filter: blur(10px);
-ms-filter: blur(10px);
filter: blur(10px);
}但是使用这种方法得出来的效果不理想(比如图片模糊后四周缩小)，而且不能局部控制图片
为了解决CSS3的缺陷，我们可以使用HTML5的canvas，用过photoshop的人一定知道里面有个高斯模糊功能，其实我们要做的就是用代码实现图片的高斯模糊转换，canvas中的getImageData方法获取图片像素信息，然后写相应的算法对图片像素进行转换
对高斯模糊的转换算法感兴趣的可以参考这篇文章—-点击打开链接
如果对这个算法实现不感兴趣，也可以用前人已经实现的JS类库StackBlur.js，毕竟前人栽树后人乘凉嘛。
这样高斯模糊效果不但非常理想，而且可以局部模糊图片
以下是测试代码：
index.html文件
<!doctype>
<html>
<head>
<title>HTML5 JS实现毛玻璃效果（高斯模糊）</title>
<link rel="stylesheet" type="text/css" href="index.css"/>
<script src="https://code.jquery.com/jquery-3.2.1.min.js"></script>
<script src="StackBlur.js" type="text/javascript"></script>
</head>
<body>
<img src='bg.jpg' id='BgImg' />
<div id='main'>
</div>
<canvas id='canvas' ></canvas>
</body>
<script>
//拖动
function change(obj,moves)
{
moves.onmousedown=function(ev)
{
var disx=0;
var disy=0;
var oev=ev||event;
disx=oev.clientX-obj.offsetLeft;
disy=oev.clientY-obj.offsetTop;
document.onmousemove=function(ev)
{
var oev=ev||event;
var l=oev.clientX-disx; //DIV x轴位置
var t=oev.clientY-disy; //DIV y轴位置
if(l<0)
{
l=0;
}
else if(l>document.documentElement.clientWidth-obj.offsetWidth)
{
l=document.documentElement.clientWidth-obj.offsetWidth;
}
if(t<0)
{
t=0;
}
obj.style.left=l+"px";
obj.style.top=t+"px";
Blur();
}
document.onmouseup=function()
{
Blur();
document.onmousemove=null;
document.onmouseup=null;
}
return false; //组织默认事件
}
}
function Blur(){
stackBlurImage( 'BgImg', 'canvas', 32,'main' );
}
window.onload=function(){
var aa = document.getElementById("canvas");
var bb = document.getElementById("main");
change(bb,bb);
}
</script>
</html> StackBlur.js文件
var mul_table = [
512,512,456,512,328,456,335,512,405,328,271,456,388,335,292,512,
454,405,364,328,298,271,496,456,420,388,360,335,312,292,273,512,
482,454,428,405,383,364,345,328,312,298,284,271,259,496,475,456,
437,420,404,388,374,360,347,335,323,312,302,292,282,273,265,512,
497,482,468,454,441,428,417,405,394,383,373,364,354,345,337,328,
320,312,305,298,291,284,278,271,265,259,507,496,485,475,465,456,
446,437,428,420,412,404,396,388,381,374,367,360,354,347,341,335,
329,323,318,312,307,302,297,292,287,282,278,273,269,265,261,512,
505,497,489,482,475,468,461,454,447,441,435,428,422,417,411,405,
399,394,389,383,378,373,368,364,359,354,350,345,341,337,332,328,
324,320,316,312,309,305,301,298,294,291,287,284,281,278,274,271,
268,265,262,259,257,507,501,496,491,485,480,475,470,465,460,456,
451,446,442,437,433,428,424,420,416,412,408,404,400,396,392,388,
385,381,377,374,370,367,363,360,357,354,350,347,344,341,338,335,
332,329,326,323,320,318,315,312,310,307,304,302,299,297,294,292,
289,287,285,282,280,278,275,273,271,269,267,265,263,261,259];
var shg_table = [
9, 11, 12, 13, 13, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 17,
17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 18, 19,
19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 20, 20, 20,
20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 21,
21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21,
21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22,
22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22,
22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 23,
23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24 ];
function stackBlurImage( imageID, canvasID, radius,maindiv )
{
var img = document.getElementById( imageID );
var canvas = document.getElementById( canvasID );
var mainDiv = document.getElementById( maindiv );
var oMainH = $(mainDiv).height();
var oMainW = $(mainDiv).width();
var oMainL = $(mainDiv).offset().left;
var oMainT = $(mainDiv).offset().top;
canvas.style.width = oMainW + "px";
canvas.style.height = oMainH + "px";
canvas.width = oMainW;
canvas.height = oMainH;
canvas.style.left = oMainL + "px";
canvas.style.top = oMainT + "px";
var context = canvas.getContext("2d");
context.clearRect( 0, 0, oMainW, oMainH );
context.drawImage( img,oMainL,oMainT,oMainW,oMainH, 0, 0 ,oMainW,oMainH );
if ( isNaN(radius) || radius < 1 ) return;
stackBlurCanvasRGBA( canvasID, 0, 0, oMainW, oMainH, radius );
}
function stackBlurCanvasRGBA( id, top_x, top_y, width, height, radius )
{
if ( isNaN(radius) || radius < 1 ) return;
radius |= 0;
var canvas = document.getElementById( id );
var context = canvas.getContext("2d");
var imageData;
try {
try {
imageData = context.getImageData( top_x, top_y, width, height );
} catch(e) {
// NOTE: this part is supposedly only needed if you want to work with local files
// so it might be okay to remove the whole try/catch block and just use
// imageData = context.getImageData( top_x, top_y, width, height );
try {
netscape.security.PrivilegeManager.enablePrivilege("UniversalBrowserRead");
imageData = context.getImageData( top_x, top_y, width, height );
} catch(e) {
alert("Cannot access local image");
throw new Error("unable to access local image data: " + e);
return;
}
}
} catch(e) {
alert("Cannot access image");
throw new Error("unable to access image data: " + e);
}
var pixels = imageData.data;
var x, y, i, p, yp, yi, yw, r_sum, g_sum, b_sum, a_sum,
r_out_sum, g_out_sum, b_out_sum, a_out_sum,
r_in_sum, g_in_sum, b_in_sum, a_in_sum,
pr, pg, pb, pa, rbs;
var div = radius + radius + 1;
var w4 = width << 2;
var widthMinus1 = width - 1;
var heightMinus1 = height - 1;
var radiusPlus1 = radius + 1;
var sumFactor = radiusPlus1 * ( radiusPlus1 + 1 ) / 2;
var stackStart = new BlurStack();
var stack = stackStart;
for ( i = 1; i < div; i++ )
{
stack = stack.next = new BlurStack();
if ( i == radiusPlus1 ) var stackEnd = stack;
}
stack.next = stackStart;
var stackIn = null;
var stackOut = null;
yw = yi = 0;
var mul_sum = mul_table[radius];
var shg_sum = shg_table[radius];
for ( y = 0; y < height; y++ )
{
r_in_sum = g_in_sum = b_in_sum = a_in_sum = r_sum = g_sum = b_sum = a_sum = 0;
r_out_sum = radiusPlus1 * ( pr = pixels[yi] );
g_out_sum = radiusPlus1 * ( pg = pixels[yi+1] );
b_out_sum = radiusPlus1 * ( pb = pixels[yi+2] );
a_out_sum = radiusPlus1 * ( pa = pixels[yi+3] );
r_sum += sumFactor * pr;
g_sum += sumFactor * pg;
b_sum += sumFactor * pb;
a_sum += sumFactor * pa;
stack = stackStart;
for( i = 0; i < radiusPlus1; i++ )
{
stack.r = pr;
stack.g = pg;
stack.b = pb;
stack.a = pa;
stack = stack.next;
}
for( i = 1; i < radiusPlus1; i++ )
{
p = yi + (( widthMinus1 < i ? widthMinus1 : i ) << 2 );
r_sum += ( stack.r = ( pr = pixels[p])) * ( rbs = radiusPlus1 - i );
g_sum += ( stack.g = ( pg = pixels[p+1])) * rbs;
b_sum += ( stack.b = ( pb = pixels[p+2])) * rbs;
a_sum += ( stack.a = ( pa = pixels[p+3])) * rbs;
r_in_sum += pr;
g_in_sum += pg;
b_in_sum += pb;
a_in_sum += pa;
stack = stack.next;
}
stackIn = stackStart;
stackOut = stackEnd;
for ( x = 0; x < width; x++ )
{
pixels[yi+3] = pa = (a_sum * mul_sum) >> shg_sum;
if ( pa != 0 )
{
pa = 255 / pa;
pixels[yi] = ((r_sum * mul_sum) >> shg_sum) * pa;
pixels[yi+1] = ((g_sum * mul_sum) >> shg_sum) * pa;
pixels[yi+2] = ((b_sum * mul_sum) >> shg_sum) * pa;
} else {
pixels[yi] = pixels[yi+1] = pixels[yi+2] = 0;
}
r_sum -= r_out_sum;
g_sum -= g_out_sum;
b_sum -= b_out_sum;
a_sum -= a_out_sum;
r_out_sum -= stackIn.r;
g_out_sum -= stackIn.g;
b_out_sum -= stackIn.b;
a_out_sum -= stackIn.a;
p = ( yw + ( ( p = x + radius + 1 ) < widthMinus1 ? p : widthMinus1 ) ) << 2;
r_in_sum += ( stackIn.r = pixels[p]);
g_in_sum += ( stackIn.g = pixels[p+1]);
b_in_sum += ( stackIn.b = pixels[p+2]);
a_in_sum += ( stackIn.a = pixels[p+3]);
r_sum += r_in_sum;
g_sum += g_in_sum;
b_sum += b_in_sum;
a_sum += a_in_sum;
stackIn = stackIn.next;
r_out_sum += ( pr = stackOut.r );
g_out_sum += ( pg = stackOut.g );
b_out_sum += ( pb = stackOut.b );
a_out_sum += ( pa = stackOut.a );
r_in_sum -= pr;
g_in_sum -= pg;
b_in_sum -= pb;
a_in_sum -= pa;
stackOut = stackOut.next;
yi += 4;
}
yw += width;
}
for ( x = 0; x < width; x++ )
{
g_in_sum = b_in_sum = a_in_sum = r_in_sum = g_sum = b_sum = a_sum = r_sum = 0;
yi = x << 2;
r_out_sum = radiusPlus1 * ( pr = pixels[yi]);
g_out_sum = radiusPlus1 * ( pg = pixels[yi+1]);
b_out_sum = radiusPlus1 * ( pb = pixels[yi+2]);
a_out_sum = radiusPlus1 * ( pa = pixels[yi+3]);
r_sum += sumFactor * pr;
g_sum += sumFactor * pg;
b_sum += sumFactor * pb;
a_sum += sumFactor * pa;
stack = stackStart;
for( i = 0; i < radiusPlus1; i++ )
{
stack.r = pr;
stack.g = pg;
stack.b = pb;
stack.a = pa;
stack = stack.next;
}
yp = width;
for( i = 1; i <= radius; i++ )
{
yi = ( yp + x ) << 2;
r_sum += ( stack.r = ( pr = pixels[yi])) * ( rbs = radiusPlus1 - i );
g_sum += ( stack.g = ( pg = pixels[yi+1])) * rbs;
b_sum += ( stack.b = ( pb = pixels[yi+2])) * rbs;
a_sum += ( stack.a = ( pa = pixels[yi+3])) * rbs;
r_in_sum += pr;
g_in_sum += pg;
b_in_sum += pb;
a_in_sum += pa;
stack = stack.next;
if( i < heightMinus1 )
{
yp += width;
}
}
yi = x;
stackIn = stackStart;
stackOut = stackEnd;
for ( y = 0; y < height; y++ )
{
p = yi << 2;
pixels[p+3] = pa = (a_sum * mul_sum) >> shg_sum;
if ( pa > 0 )
{
pa = 255 / pa;
pixels[p] = ((r_sum * mul_sum) >> shg_sum ) * pa;
pixels[p+1] = ((g_sum * mul_sum) >> shg_sum ) * pa;
pixels[p+2] = ((b_sum * mul_sum) >> shg_sum ) * pa;
} else {
pixels[p] = pixels[p+1] = pixels[p+2] = 0;
}
r_sum -= r_out_sum;
g_sum -= g_out_sum;
b_sum -= b_out_sum;
a_sum -= a_out_sum;
r_out_sum -= stackIn.r;
g_out_sum -= stackIn.g;
b_out_sum -= stackIn.b;
a_out_sum -= stackIn.a;
p = ( x + (( ( p = y + radiusPlus1) < heightMinus1 ? p : heightMinus1 ) * width )) << 2;
r_sum += ( r_in_sum += ( stackIn.r = pixels[p]));
g_sum += ( g_in_sum += ( stackIn.g = pixels[p+1]));
b_sum += ( b_in_sum += ( stackIn.b = pixels[p+2]));
a_sum += ( a_in_sum += ( stackIn.a = pixels[p+3]));
stackIn = stackIn.next;
r_out_sum += ( pr = stackOut.r );
g_out_sum += ( pg = stackOut.g );
b_out_sum += ( pb = stackOut.b );
a_out_sum += ( pa = stackOut.a );
r_in_sum -= pr;
g_in_sum -= pg;
b_in_sum -= pb;
a_in_sum -= pa;
stackOut = stackOut.next;
yi += width;
}
}
context.putImageData( imageData, top_x, top_y );
}
function BlurStack()
{
this.r = 0;
this.g = 0;
this.b = 0;
this.a = 0;
this.next = null;
}index.css文件
body{
background:#000000;
overflow:hidden;
}
#BgImg{
position:absolute;
z-index:-100;
}
#main{
width:700px;
height:700px;
color:#ffffff;
position:absolute;
z-index:12;
left:150px;
top:30px;
border-radius:1px;
box-shadow:-1px -1px 4px rgba(115,115,115,0.6) inset,
1px 1px 4px rgba(115,115,115,0.6) inset;
}
#canvas{
z-index:1;
position:absolute;
} 上述就是根据StackBlur.js实现的一个毛玻璃的效果
代码演示及源码下载
[infobox]演示:毛玻璃效果[/infobox][warningbox]源码下载：maoboli.zip[/warningbox]
本文参与 腾讯云自媒体分享计划，分享自作者个人站点/博客。
原始发表：2018年1月1日，如有侵权请联系 cloudcommunity@tencent.com 删除
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