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Codefreigabe für den Bildunschärfealgorithmus, implementiert in JavaScript_Javascript-Kenntnissen

WBOY
Freigeben： 2016-05-16 16:51:40
Original
1653 Leute haben es durchsucht

Im Projekt müssen unscharfe HTML5-Bilder verwendet werden. Es gibt vorgefertigte Komponenten in GDI, um es in HTML5 zu implementieren.
1.createImageData()
2.getImageData()
3.putImageData()
Zur Verwendung und Geheimnissen gehen Sie bitte zu Baidu selbst die Beschreibung macht wenig Sinn.

Das Folgende ist der JS, der den Fuzzy-Algorithmus implementiert. Tatsächlich gibt es einen anderen 2B-Level-Algorithmus, nämlich die Verteilungsmatrix, der die Effizienz um ein Vielfaches erhöht, aber der Effekt ist sehr schlecht und der Feathering-Effekt ist nicht stark.
Implementierungscode:

Code kopieren Der Code lautet wie folgt:

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, blurAlphaChannel )
{

     var img = document.getElementById( imageID );
    var w = img.naturalWidth;
    var h = img.naturalHeight;

    var canvas = document.getElementById( canvasID );

    canvas.style.width  = w + "px";
    canvas.style.height = h + "px";
    canvas.width = w;
    canvas.height = h;

    var context = canvas.getContext("2d");
    context.clearRect( 0, 0, w, h );
    context.drawImage( img, 0, 0 );

    if ( isNaN(radius) || radius < 1 ) return;

if ( blurAlphaChannel )
stackBlurCanvasRGBA( canvasID, 0, 0, w, h, radius );
else
stackBlurCanvasRGB( canvasID, 0, 0, w, h, 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) {

    
        try {
            netscape.security.PrivilegeManager.enablePrivilege( "UniversalBrowserRead");
            imageData = context.getImageData( top_x, top_y, width, height );
        } Catch(e) {
            Alert("Zugriff auf lokales Bild nicht möglich");
            throw new Fehler("Zugriff auf lokale Bilddaten nicht möglich: " e);
            return;
        }
      }
    } Catch(e) {
      Alert("Zugriff auf Bild nicht möglich");
      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, pb, pa, rbs, <🎜,
pr, pg, pb, pb, pa, rbs, <🎜sum,
pr, pg, pb, pb, pa, rbs;
    var div = Radius Radius 1;
    var w4 = Breite << 2;
    var widthMinus1  = Breite - 1;
    var heightMinus1 = Höhe - 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; ich < 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 = Breite;

        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 )
            ;
        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;
                Pixel[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 stackBlurCanvasRGB( 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) {

 
        try {
            netscape.security.PrivilegeManager.enablePrivilege( "UniversalBrowserRead");
            imageData = context.getImageData( top_x, top_y, width, height );
        } Catch(e) {
            Alert("Zugriff auf lokales Bild nicht möglich");
            throw new Fehler("Zugriff auf lokale Bilddaten nicht möglich: " e);
            return;
        }
      }
    } Catch(e) {
      Alert("Zugriff auf Bild nicht möglich");
      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,
    r_out_sum, g_out_sum, b_out_sum,
    r_in_sum, g_in_sum, b_in_sum,
    pr, pg, pb, rbs;

    var div = radius uns 1;
    var w4 = Breite << 2;
    var widthMinus1  = Breite - 1;
    var heightMinus1 = Höhe - 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 = r_sum = g_sum = b_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] );

        r_sum = sumFactor * pr;
        g_sum = sumFactor * pg;
b_sum = sumFactor * pb;

        stack = stackStart;

        for( i = 0; ich < radiusPlus1; i )
        {
            stack.r = pr;
            stack.g = pg;
            stack.b = pb;
            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;

r_in_sum += pr;
g_in_sum += pg;
b_in_sum += pb;

stack = stack.next;
}


stackIn = stackStart;
stackOut = stackEnd;
for ( x = 0; x < width; x++ )
{
pixels[yi] = (r_sum * mul_sum) >> shg_sum;
            pixels[yi+1] = (g_sum * mul_sum) >> shg_sum;
            pixels[yi+2] = (b_sum * mul_sum) >> shg_sum;

            r_sum -= r_out_sum;
            g_sum -= g_out_sum;
            b_sum -= b_out_sum;

            r_out_sum -= stackIn.r;
            g_out_sum -= stackIn.g;
            b_out_sum -= stackIn.b;

            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]);

r_sum += r_in_sum;
g_sum += g_in_sum;
b_sum += b_in_sum;

stackIn = stackIn.next;

r_out_sum += ( pr = stackOut.r );
g_out_sum += ( pg = stackOut.g );
b_out_sum += ( pb = stackOut.b );

r_in_sum -= pr;
g_in_sum -= pg;
b_in_sum -= pb;

stackOut = stackOut.next;

yi += 4;
}
yw += width;
}

   
    for ( x = 0; x < width; x )
    {
        g_in_sum = b_in_sum = r_in_sum = g_sum = b_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] );

        r_sum = sumFactor * pr;
        g_sum = sumFactor * pg;
        b_sum = sumFactor * pb;

        für( i = 0; i < radiusPlus1; i )
            stack.r = pr;
            stack.b = pb;
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;

            r_in_sum = pr;
            g_in_sum =. pg;
            b_in_sum = pb;

            stack = stack.next;

            if( i < heightMinus1 )
            {
               yp =. width;
           }
        }

        yi = x;
        stackIn = stackStart;
        stackOut = stackEnd;
        for ( y = 0; y < height; y )
       . {
            p = yi << 2;
            Pixel[p]   = (r_sum * mul_sum) >> shg_sum;
            pixels[p 1] = (g_sum * mul_sum) >> shg_sum;
            pixels[p 2] = (b_sum * mul_sum) >> shg_sum;

            r_sum -= r_out_sum;
            g_sum -= g_out_sum;
            b_sum -= b_out_sum;

          . r_out _sum -= stackIn.r;
            g_out_sum -= stackIn. g;
            b_out_sum -= stackIn.b;

            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]));

            stackIn = stackIn.next;

            r_out_sum = ( pr = stackOut.r );
            g_out_sum = ( pg = stackOut.g ​​);
            b_out_sum = ( pb = stackOut.b );

            r_in_sum -= pr;
            g_in_sum -= pg;
            b_ in_sum -= pb;

            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;
}

使用方法：

复制代码 代码如下:
stackblurimage (scellImageId, targetCanvasid, Radius, Bluralphachannel); ( targetCanvasID, top_x, top_y, Breite, Höhe, Radius );
stackBlurCanvasRGB( targetCanvasID, top_x, top_y, Breite, Höhe, Radius );
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