1.图片设置为灰色source：图片路经源
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(); } }原文地址：http://blog.csdn.net/sweiqin/article/details/45041701
