java画图如何实现windows里图标的选中效果，颜色加深变蓝，透明处不变！

[nil2000]

这个问题搞我好长时间，一般使用到java的RGBFilter,或者直接对色彩做alpha或其他变换，但我实现的都变为一种颜色了，原来的不见了。
最多只能给200，解决问题者，再送200。
能给出代码最好，不行给个思路。

[simonhappy]

试试Graphics2D中的这个类AffineTransform或者Graphics2D关联的类.
我的思路是如果前景是单色,用一些颜色的与或运算就可以了.如果是一个图片之类的东西,那么必须有一个地方可以统一处理输出前的转换,以前在AffineTransform处理过输出比例的问题,你可以看看Graphics2D其他的类.

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[nil2000]

谢楼上先,再顶

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[wobelisk]

AffineTransform is not enough. It does not process Alpha or transparence 透明.

I used raster to do this.
If the image (.gif) has alpha channel, transform only pixels which alpha !=0.
If the image (.jpg) has no alpha channel, it become a little more complex. If I know the image has white( or other) background, the only transfor pixels are not white.

Process:
Image src=..... //width,height
BufferedImage proc= new BufferedImage(width,height,BufferedImage.TYPE_INT_ARGB);
Graphics2D g2=proc.createGraphics();
g2.drawImage(src,width,height,null); //offscreen copy src to proc

Raster rSrc=proc.getRaster();
ColorModel cm=proc.getColorModel();

float[][] matrix={ //alpha blend: src*0.75+dst*0.25, dst is a blue rect
{0.75f,0,0,0,0}, //red
{0,0.75f,0,0,0}, //green
{0,0,0.75f,0,255*0.25f}, //blue, increase blue channel
{0,0,0,0.75f,255*0.25f} //alpha
}

BandCombineOp op=new BandCombineOp(matrix, null){
// override filter to process alpha channel
public WritableRaster filter(Raster src,
WritableRaster dst){

...//src.getPixel
...//getAlpha
...//if has alpha channel and alpha!=0 use matrix to transfor
...//if no ahpha channel, and pixel color is not the background,
//do transform
.. //dst.setPixel

return dst;
}
}

WritableRaster rDst=op.filter(rSrc,rSrc); //op.filter(rSrc,null) is the same
BufferedImage dst=new BufferedImage(cm, rDst,false,null);


//draw dst to the screen if selected.

1.op.filter() refer to j2sdk source code, add the code to process alpha
2.adjust 0.75f to other numbers to get the effect you want.

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[nil2000]

等了几天，问题还没有很好的解决，但已经有替代方法了。所以还是很感谢楼上两位。
分就一人一半吧。

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