问在flex中为图像添加对比度和亮度

EN

var contrastAdj:ColorMatrixFilter = ColorMatrixFilter(filters.getItemAt(0));
        contrastAdj.matrix = getContrastMatrix(value);

    private static function getContrastMatrix(value:Number):Array
    {

    value /= 100;
    var s: Number = value + 1;
    var o : Number = 128 * (1 - s);
    var m:Array = new Array();
    m = m.concat([s, 0, 0, 0, o]);  // red
    m = m.concat([0, s, 0, 0, o]);  // green
    m = m.concat([0, 0, s, 0, o]);  // blue
    m = m.concat([0, 0, 0, 1, 0]);  // alpha

    return m;
}

private static function getBrightnessMatrix(value:Number):Array
{
                var m:Array = new Array();
                m = m.concat([1, 0, 0, 0, value]);  // red
                m = m.concat([0, 1, 0, 0, value]);  // green
                m = m.concat([0, 0, 1, 0, value]);  // blue
                m = m.concat([0, 0, 0, 1, 0]);      // alpha
                return m;
        }