Android 图片设置为灰色

1.图片设置为灰色
source：图片路经源
dest：图片目的地
public  static  void  toGrayImage(String source, String dest)
    {
        try
        {
            Bitmap bitmap = BitmapFactory.decodeFile(source);

            int  width = bitmap.getWidth();
            int  height = bitmap.getHeight();
            Bitmap grayImg = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
            //
            Canvas canvas =  new  Canvas(grayImg);

            Paint paint =  new  Paint();
            ColorMatrix colorMatrix =  new  ColorMatrix();
            colorMatrix.setSaturation( 0 );
            ColorMatrixColorFilter colorMatrixFilter =  new  ColorMatrixColorFilter(
                    colorMatrix);
            paint.setColorFilter(colorMatrixFilter);
            canvas.drawBitmap(bitmap,  0 ,  0 , paint);
            // canvas.
            File file =  new  File(dest);
            boolean  success = file.createNewFile();
            FileOutputStream stream =  new  FileOutputStream(file);
            grayImg.compress(CompressFormat.JPEG,  100 , stream);
            stream.flush();
            stream.close();

            bitmap.recycle();
            grayImg.recycle();

        }
        catch  (Exception e)
        {
            @SuppressWarnings ( "unused" )
            String msg = e.getMessage();
        }

    }