android为图片去色,返回灰度图片

就是大家喜闻乐见的图片去色，返回黑白的图片，具体的方法就是为bitmap添加colorFilter，废话不多说了，上代码：

public static Bitmap getGreyImage(Bitmap old) {

int width, height;

height = old.getHeight();

width = old.getWidth();

Bitmap new= Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);

Canvas c = new Canvas(old);

Paint paint = new Paint();

ColorMatrix cm = new ColorMatrix();

cm.setSaturation(0);

ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm);

paint.setColorFilter(f);

c.drawBitmap(new, 0, 0, paint);

return new;

}