查API的时候查到一个ColorTransform类，觉得这个类应该可以完成我需要的功能，不过现在还是想不到应该怎么样才能实现这个需求
哈哈，谢谢！
功能实现了，经你一提醒，我试了一下把MC的饱和度和亮度都设为－100，差不多就是我想要的效果
代码如下：
var color:ColorMatrix = new ColorMatrix();
color.adjustSaturation(-100);
color.adjustBrightness(-100);
mc.filters = [new ColorMatrixFilter(color)];
以下是ColorMatrix类（此类是他人作品，使用请加上作者信息，谢谢！）:
/**
* ColorMatrix by Grant Skinner. August 8, 2005
* Updated to AS3 November 19, 2007
* Visit www.gskinner.com/blog for documentation, updates and more free code.
*
* You may distribute this class freely, provided it is not modified in any way (including
* removing this header or changing the package path).
*
* Please contact info@gskinner.com prior to distributing modified versions of this class.
*usage:http://www.gskinner.com/blog/archives/2005/09/flash_8_source.html
*var cm = new ColorMatrix();
* cm.adjustColor(20,20,20,20);
*displayObject.filters = [new ColorMatrixFilter(cm)];
*/
package
{
dynamic public class ColorMatrix extends Array
{
// constant for contrast calculations:
private static const DELTA_INDEX:Array = [
0, 0.01, 0.02, 0.04, 0.05, 0.06, 0.07, 0.08, 0.1, 0.11,
0.12, 0.14, 0.15, 0.16, 0.17, 0.18, 0.20, 0.21, 0.22, 0.24,
0.25, 0.27, 0.28, 0.30, 0.32, 0.34, 0.36, 0.38, 0.40, 0.42,
0.44, 0.46, 0.48, 0.5, 0.53, 0.56, 0.59, 0.62, 0.65, 0.68,
0.71, 0.74, 0.77, 0.80, 0.83, 0.86, 0.89, 0.92, 0.95, 0.98,
1.0, 1.06, 1.12, 1.18, 1.24, 1.30, 1.36, 1.42, 1.48, 1.54,
1.60, 1.66, 1.72, 1.78, 1.84, 1.90, 1.96, 2.0, 2.12, 2.25,
2.37, 2.50, 2.62, 2.75, 2.87, 3.0, 3.2, 3.4, 3.6, 3.8,
4.0, 4.3, 4.7, 4.9, 5.0, 5.5, 6.0, 6.5, 6.8, 7.0,
7.3, 7.5, 7.8, 8.0, 8.4, 8.7, 9.0, 9.4, 9.6, 9.8,
10.0
];
// identity matrix constant:
private static const IDENTITY_MATRIX:Array = [
1,0,0,0,0,
0,1,0,0,0,
0,0,1,0,0,
0,0,0,1,0,
0,0,0,0,1
];
private static const LENGTH:Number = IDENTITY_MATRIX.length;
// initialization:
public function ColorMatrix(p_matrix:Array = null)
{
p_matrix = fixMatrix(p_matrix);
copyMatrix(((p_matrix.length == LENGTH) ? p_matrix : IDENTITY_MATRIX));
}
// public methods:
public function reset():void
{
for (var i:uint = 0; i < LENGTH; i++)
{
this[i] = IDENTITY_MATRIX[i];
}
}
public function adjustColor(p_brightness:Number, p_contrast:Number, p_saturation:Number, p_hue:Number):void
{
adjustHue(p_hue);
adjustContrast(p_contrast);
adjustBrightness(p_brightness);
adjustSaturation(p_saturation);
}
public function adjustBrightness(p_val:Number):void {
p_val = cleanValue(p_val, 100);
if (p_val == 0 || isNaN(p_val))
{
return;
}
multiplyMatrix([
1,0,0,0,p_val,
0,1,0,0,p_val,
0,0,1,0,p_val,
0,0,0,1,0,
0,0,0,0,1
]);
}
public function adjustContrast(p_val:Number):void
{
p_val = cleanValue(p_val, 100);
if (p_val == 0 || isNaN(p_val))
{
return;
}
var x:Number;
if (p_val < 0)
{
x = 127 + p_val / 100 * 127;
}
else
{
x = p_val % 1;
if (x == 0)
{
x = DELTA_INDEX[p_val];
}
else
{
//x = DELTA_INDEX[(p_val<<0)]; // this is how the IDE does it.
x = DELTA_INDEX[(p_val << 0)] * (1 - x) + DELTA_INDEX[(p_val << 0) + 1] * x; // use linear interpolation for more granularity.
}
x = x * 127 + 127;
}
multiplyMatrix([
x/127,0,0,0,0.5*(127-x),
0,x/127,0,0,0.5*(127-x),
0,0,x/127,0,0.5*(127-x),
0,0,0,1,0,
0,0,0,0,1
]);
}
public function adjustSaturation(p_val:Number):void
{
p_val = cleanValue(p_val, 100);
if (p_val == 0 || isNaN(p_val))
{
return;
}
var x:Number = 1 + ((p_val > 0) ? 3 * p_val / 100 : p_val / 100);
var lumR:Number = 0.3086;
var lumG:Number = 0.6094;
var lumB:Number = 0.0820;
multiplyMatrix([
lumR*(1-x)+x,lumG*(1-x),lumB*(1-x),0,0,
lumR*(1-x),lumG*(1-x)+x,lumB*(1-x),0,0,
lumR*(1-x),lumG*(1-x),lumB*(1-x)+x,0,0,
0,0,0,1,0,
0,0,0,0,1
]);
}
public function adjustHue(p_val:Number):void
{
p_val = cleanValue(p_val, 180) / 180 * Math.PI;
if (p_val == 0 || isNaN(p_val))
{
return;
}
var cosVal:Number = Math.cos(p_val);
var sinVal:Number = Math.sin(p_val);
var lumR:Number = 0.213;
var lumG:Number = 0.715;
var lumB:Number = 0.072;
multiplyMatrix([
lumR+cosVal*(1-lumR)+sinVal*(-lumR),lumG+cosVal*(-lumG)+sinVal*(-lumG),lumB+cosVal*(-lumB)+sinVal*(1-lumB),0,0,
lumR+cosVal*(-lumR)+sinVal*(0.143),lumG+cosVal*(1-lumG)+sinVal*(0.140),lumB+cosVal*(-lumB)+sinVal*(-0.283),0,0,
lumR+cosVal*(-lumR)+sinVal*(-(1-lumR)),lumG+cosVal*(-lumG)+sinVal*(lumG),lumB+cosVal*(1-lumB)+sinVal*(lumB),0,0,
0,0,0,1,0,
0,0,0,0,1
]);
}
public function concat(p_matrix:Array):void
{
p_matrix = fixMatrix(p_matrix);
if (p_matrix.length != LENGTH)
{
return;
}
multiplyMatrix(p_matrix);
}
public function clone():ColorMatrix
{
return new ColorMatrix(this);
}
public function toString():String
{
return "ColorMatrix [ " + this.join(" , ") + " ]";
}
// return a length 20 array (5x4):
public function toArray():Array
{
return slice(0, 20);
}
// private methods:
// copy the specified matrix's values to this matrix:
protected function copyMatrix(p_matrix:Array):void
{
var l:Number = LENGTH;
for (var i:uint = 0; i < l; i++)
{
this[i] = p_matrix[i];
}
}
// multiplies one matrix against another:
protected function multiplyMatrix(p_matrix:Array):void
{
var col:Array = [];
for (var i:uint = 0; i < 5; i++)
{
for (var j:uint = 0; j < 5; j++)
{
col[j] = this[j + i * 5];
}
for (j = 0; j < 5; j++)
{
var val:Number = 0;
for (var k:Number = 0; k < 5; k++)
{
val += p_matrix[j + k * 5] * col[k];
}
this[j + i * 5] = val;
}
}
}
// make sure values are within the specified range, hue has a limit of 180, others are 100:
protected function cleanValue(p_val:Number, p_limit:Number):Number
{
return Math.min(p_limit, Math.max(-p_limit, p_val));
}
// makes sure matrixes are 5x5 (25 long):
protected function fixMatrix(p_matrix:Array = null):Array
{
if (p_matrix == null)
{
return IDENTITY_MATRIX;
}
if (p_matrix is ColorMatrix)
{
p_matrix = p_matrix.slice(0);
}
if (p_matrix.length < LENGTH)
{
p_matrix = p_matrix.slice(0, p_matrix.length).concat(IDENTITY_MATRIX.slice(p_matrix.length, LENGTH));
}
else if (p_matrix.length > LENGTH)
{
p_matrix = p_matrix.slice(0, LENGTH);
}
return p_matrix;
}
}
}